diff --git a/lib/std/Io.zig b/lib/std/Io.zig
index b90276cfab..c55c28f177 100644
--- a/lib/std/Io.zig
+++ b/lib/std/Io.zig
@@ -438,8 +438,6 @@ pub fn GenericWriter(
 pub const AnyReader = @import("Io/DeprecatedReader.zig");
 /// Deprecated in favor of `Writer`.
 pub const AnyWriter = @import("Io/DeprecatedWriter.zig");
-/// Deprecated in favor of `File.Reader` and `File.Writer`.
-pub const SeekableStream = @import("Io/seekable_stream.zig").SeekableStream;
 /// Deprecated in favor of `Writer`.
 pub const BufferedWriter = @import("Io/buffered_writer.zig").BufferedWriter;
 /// Deprecated in favor of `Writer`.
@@ -467,12 +465,6 @@ pub const CountingReader = @import("Io/counting_reader.zig").CountingReader;
 /// Deprecated with no replacement; inefficient pattern
 pub const countingReader = @import("Io/counting_reader.zig").countingReader;
 
-pub const BitReader = @import("Io/bit_reader.zig").BitReader;
-pub const bitReader = @import("Io/bit_reader.zig").bitReader;
-
-pub const BitWriter = @import("Io/bit_writer.zig").BitWriter;
-pub const bitWriter = @import("Io/bit_writer.zig").bitWriter;
-
 pub const tty = @import("Io/tty.zig");
 
 /// Deprecated in favor of `Writer.Discarding`.
@@ -948,16 +940,12 @@ pub fn PollFiles(comptime StreamEnum: type) type {
 
 test {
     _ = Reader;
-    _ = Reader.Limited;
     _ = Writer;
-    _ = BitReader;
-    _ = BitWriter;
     _ = BufferedReader;
     _ = BufferedWriter;
     _ = CountingWriter;
     _ = CountingReader;
     _ = FixedBufferStream;
-    _ = SeekableStream;
     _ = tty;
     _ = @import("Io/test.zig");
 }
diff --git a/lib/std/Io/Reader.zig b/lib/std/Io/Reader.zig
index 7ba58bfbf4..05ab489286 100644
--- a/lib/std/Io/Reader.zig
+++ b/lib/std/Io/Reader.zig
@@ -74,6 +74,10 @@ pub const VTable = struct {
     ///
     /// `data` may not contain an alias to `Reader.buffer`.
     ///
+    /// `data` is mutable because the implementation may to temporarily modify
+    /// the fields in order to handle partial reads. Implementations must
+    /// restore the original value before returning.
+    ///
     /// Implementations may ignore `data`, writing directly to `Reader.buffer`,
     /// modifying `seek` and `end` accordingly, and returning 0 from this
     /// function. Implementations are encouraged to take advantage of this if
@@ -81,7 +85,7 @@ pub const VTable = struct {
     ///
     /// The default implementation calls `stream` with either `data[0]` or
     /// `Reader.buffer`, whichever is bigger.
-    readVec: *const fn (r: *Reader, data: []const []u8) Error!usize = defaultReadVec,
+    readVec: *const fn (r: *Reader, data: [][]u8) Error!usize = defaultReadVec,
 
     /// Ensures `capacity` more data can be buffered without rebasing.
     ///
@@ -262,8 +266,7 @@ pub fn streamRemaining(r: *Reader, w: *Writer) StreamRemainingError!usize {
 /// number of bytes discarded.
 pub fn discardRemaining(r: *Reader) ShortError!usize {
     var offset: usize = r.end - r.seek;
-    r.seek = 0;
-    r.end = 0;
+    r.seek = r.end;
     while (true) {
         offset += r.vtable.discard(r, .unlimited) catch |err| switch (err) {
             error.EndOfStream => return offset,
@@ -417,7 +420,7 @@ pub fn readVec(r: *Reader, data: [][]u8) Error!usize {
 }
 
 /// Writes to `Reader.buffer` or `data`, whichever has larger capacity.
-pub fn defaultReadVec(r: *Reader, data: []const []u8) Error!usize {
+pub fn defaultReadVec(r: *Reader, data: [][]u8) Error!usize {
     assert(r.seek == r.end);
     r.seek = 0;
     r.end = 0;
@@ -438,23 +441,6 @@ pub fn defaultReadVec(r: *Reader, data: []const []u8) Error!usize {
     return 0;
 }
 
-/// Always writes to `Reader.buffer` and returns 0.
-pub fn indirectReadVec(r: *Reader, data: []const []u8) Error!usize {
-    _ = data;
-    assert(r.seek == r.end);
-    var writer: Writer = .{
-        .buffer = r.buffer,
-        .end = r.end,
-        .vtable = &.{ .drain = Writer.fixedDrain },
-    };
-    const limit: Limit = .limited(writer.buffer.len - writer.end);
-    r.end += r.vtable.stream(r, &writer, limit) catch |err| switch (err) {
-        error.WriteFailed => unreachable,
-        else => |e| return e,
-    };
-    return 0;
-}
-
 pub fn buffered(r: *Reader) []u8 {
     return r.buffer[r.seek..r.end];
 }
@@ -463,8 +449,8 @@ pub fn bufferedLen(r: *const Reader) usize {
     return r.end - r.seek;
 }
 
-pub fn hashed(r: *Reader, hasher: anytype) Hashed(@TypeOf(hasher)) {
-    return .{ .in = r, .hasher = hasher };
+pub fn hashed(r: *Reader, hasher: anytype, buffer: []u8) Hashed(@TypeOf(hasher)) {
+    return .init(r, hasher, buffer);
 }
 
 pub fn readVecAll(r: *Reader, data: [][]u8) Error!void {
@@ -539,8 +525,7 @@ pub fn toss(r: *Reader, n: usize) void {
 
 /// Equivalent to `toss(r.bufferedLen())`.
 pub fn tossBuffered(r: *Reader) void {
-    r.seek = 0;
-    r.end = 0;
+    r.seek = r.end;
 }
 
 /// Equivalent to `peek` followed by `toss`.
@@ -627,8 +612,7 @@ pub fn discardShort(r: *Reader, n: usize) ShortError!usize {
         return n;
     }
     var remaining = n - (r.end - r.seek);
-    r.end = 0;
-    r.seek = 0;
+    r.seek = r.end;
     while (true) {
         const discard_len = r.vtable.discard(r, .limited(remaining)) catch |err| switch (err) {
             error.EndOfStream => return n - remaining,
@@ -1678,7 +1662,7 @@ fn endingStream(r: *Reader, w: *Writer, limit: Limit) StreamError!usize {
     return error.EndOfStream;
 }
 
-fn endingReadVec(r: *Reader, data: []const []u8) Error!usize {
+fn endingReadVec(r: *Reader, data: [][]u8) Error!usize {
     _ = r;
     _ = data;
     return error.EndOfStream;
@@ -1709,6 +1693,15 @@ fn failingDiscard(r: *Reader, limit: Limit) Error!usize {
     return error.ReadFailed;
 }
 
+pub fn adaptToOldInterface(r: *Reader) std.Io.AnyReader {
+    return .{ .context = r, .readFn = derpRead };
+}
+
+fn derpRead(context: *const anyopaque, buffer: []u8) anyerror!usize {
+    const r: *Reader = @constCast(@alignCast(@ptrCast(context)));
+    return r.readSliceShort(buffer);
+}
+
 test "readAlloc when the backing reader provides one byte at a time" {
     const str = "This is a test";
     var tiny_buffer: [1]u8 = undefined;
@@ -1772,15 +1765,16 @@ pub fn Hashed(comptime Hasher: type) type {
     return struct {
         in: *Reader,
         hasher: Hasher,
-        interface: Reader,
+        reader: Reader,
 
         pub fn init(in: *Reader, hasher: Hasher, buffer: []u8) @This() {
             return .{
                 .in = in,
                 .hasher = hasher,
-                .interface = .{
+                .reader = .{
                     .vtable = &.{
-                        .read = @This().read,
+                        .stream = @This().stream,
+                        .readVec = @This().readVec,
                         .discard = @This().discard,
                     },
                     .buffer = buffer,
@@ -1790,33 +1784,39 @@ pub fn Hashed(comptime Hasher: type) type {
             };
         }
 
-        fn read(r: *Reader, w: *Writer, limit: Limit) StreamError!usize {
-            const this: *@This() = @alignCast(@fieldParentPtr("interface", r));
-            const data = w.writableVector(limit);
+        fn stream(r: *Reader, w: *Writer, limit: Limit) StreamError!usize {
+            const this: *@This() = @alignCast(@fieldParentPtr("reader", r));
+            const data = limit.slice(try w.writableSliceGreedy(1));
+            var vec: [1][]u8 = .{data};
+            const n = try this.in.readVec(&vec);
+            this.hasher.update(data[0..n]);
+            w.advance(n);
+            return n;
+        }
+
+        fn readVec(r: *Reader, data: [][]u8) Error!usize {
+            const this: *@This() = @alignCast(@fieldParentPtr("reader", r));
             const n = try this.in.readVec(data);
-            const result = w.advanceVector(n);
             var remaining: usize = n;
             for (data) |slice| {
                 if (remaining < slice.len) {
                     this.hasher.update(slice[0..remaining]);
-                    return result;
+                    return n;
                 } else {
                     remaining -= slice.len;
                     this.hasher.update(slice);
                 }
             }
             assert(remaining == 0);
-            return result;
+            return n;
         }
 
         fn discard(r: *Reader, limit: Limit) Error!usize {
-            const this: *@This() = @alignCast(@fieldParentPtr("interface", r));
-            var w = this.hasher.writer(&.{});
-            const n = this.in.stream(&w, limit) catch |err| switch (err) {
-                error.WriteFailed => unreachable,
-                else => |e| return e,
-            };
-            return n;
+            const this: *@This() = @alignCast(@fieldParentPtr("reader", r));
+            const peeked = limit.slice(try this.in.peekGreedy(1));
+            this.hasher.update(peeked);
+            this.in.toss(peeked.len);
+            return peeked.len;
         }
     };
 }
@@ -1874,3 +1874,7 @@ pub fn writableVectorWsa(
     }
     return .{ i, n };
 }
+
+test {
+    _ = Limited;
+}
diff --git a/lib/std/Io/Writer.zig b/lib/std/Io/Writer.zig
index a177bda8ff..a84077f8f3 100644
--- a/lib/std/Io/Writer.zig
+++ b/lib/std/Io/Writer.zig
@@ -2266,7 +2266,7 @@ pub fn fixedDrain(w: *Writer, data: []const []const u8, splat: usize) Error!usiz
     const pattern = data[data.len - 1];
     const dest = w.buffer[w.end..];
     switch (pattern.len) {
-        0 => return w.end,
+        0 => return 0,
         1 => {
             assert(splat >= dest.len);
             @memset(dest, pattern[0]);
@@ -2286,6 +2286,13 @@ pub fn fixedDrain(w: *Writer, data: []const []const u8, splat: usize) Error!usiz
     }
 }
 
+pub fn unreachableDrain(w: *Writer, data: []const []const u8, splat: usize) Error!usize {
+    _ = w;
+    _ = data;
+    _ = splat;
+    unreachable;
+}
+
 /// Provides a `Writer` implementation based on calling `Hasher.update`, sending
 /// all data also to an underlying `Writer`.
 ///
@@ -2296,6 +2303,8 @@ pub fn fixedDrain(w: *Writer, data: []const []const u8, splat: usize) Error!usiz
 /// generic. A better solution will involve creating a writer for each hash
 /// function, where the splat buffer can be tailored to the hash implementation
 /// details.
+///
+/// Contrast with `Hashing` which terminates the stream pipeline.
 pub fn Hashed(comptime Hasher: type) type {
     return struct {
         out: *Writer,
@@ -2341,7 +2350,7 @@ pub fn Hashed(comptime Hasher: type) type {
                 this.hasher.update(slice);
             }
             const pattern = data[data.len - 1];
-            assert(remaining == splat * pattern.len);
+            assert(remaining <= splat * pattern.len);
             switch (pattern.len) {
                 0 => {
                     assert(remaining == 0);
@@ -2368,6 +2377,52 @@ pub fn Hashed(comptime Hasher: type) type {
     };
 }
 
+/// Provides a `Writer` implementation based on calling `Hasher.update`,
+/// discarding all data.
+///
+/// This implementation makes suboptimal buffering decisions due to being
+/// generic. A better solution will involve creating a writer for each hash
+/// function, where the splat buffer can be tailored to the hash implementation
+/// details.
+///
+/// The total number of bytes written is stored in `hasher`.
+///
+/// Contrast with `Hashed` which also passes the data to an underlying stream.
+pub fn Hashing(comptime Hasher: type) type {
+    return struct {
+        hasher: Hasher,
+        writer: Writer,
+
+        pub fn init(buffer: []u8) @This() {
+            return .initHasher(.init(.{}), buffer);
+        }
+
+        pub fn initHasher(hasher: Hasher, buffer: []u8) @This() {
+            return .{
+                .hasher = hasher,
+                .writer = .{
+                    .buffer = buffer,
+                    .vtable = &.{ .drain = @This().drain },
+                },
+            };
+        }
+
+        fn drain(w: *Writer, data: []const []const u8, splat: usize) Error!usize {
+            const this: *@This() = @alignCast(@fieldParentPtr("writer", w));
+            const hasher = &this.hasher;
+            hasher.update(w.buffered());
+            w.end = 0;
+            var n: usize = 0;
+            for (data[0 .. data.len - 1]) |slice| {
+                hasher.update(slice);
+                n += slice.len;
+            }
+            for (0..splat) |_| hasher.update(data[data.len - 1]);
+            return n + splat * data[data.len - 1].len;
+        }
+    };
+}
+
 /// Maintains `Writer` state such that it writes to the unused capacity of an
 /// array list, filling it up completely before making a call through the
 /// vtable, causing a resize. Consequently, the same, optimized, non-generic
diff --git a/lib/std/Io/bit_reader.zig b/lib/std/Io/bit_reader.zig
deleted file mode 100644
index 7823e47d43..0000000000
--- a/lib/std/Io/bit_reader.zig
+++ /dev/null
@@ -1,238 +0,0 @@
-const std = @import("../std.zig");
-
-//General note on endianess:
-//Big endian is packed starting in the most significant part of the byte and subsequent
-// bytes contain less significant bits. Thus we always take bits from the high
-// end and place them below existing bits in our output.
-//Little endian is packed starting in the least significant part of the byte and
-// subsequent bytes contain more significant bits. Thus we always take bits from
-// the low end and place them above existing bits in our output.
-//Regardless of endianess, within any given byte the bits are always in most
-// to least significant order.
-//Also regardless of endianess, the buffer always aligns bits to the low end
-// of the byte.
-
-/// Creates a bit reader which allows for reading bits from an underlying standard reader
-pub fn BitReader(comptime endian: std.builtin.Endian, comptime Reader: type) type {
-    return struct {
-        reader: Reader,
-        bits: u8 = 0,
-        count: u4 = 0,
-
-        const low_bit_mask = [9]u8{
-            0b00000000,
-            0b00000001,
-            0b00000011,
-            0b00000111,
-            0b00001111,
-            0b00011111,
-            0b00111111,
-            0b01111111,
-            0b11111111,
-        };
-
-        fn Bits(comptime T: type) type {
-            return struct {
-                T,
-                u16,
-            };
-        }
-
-        fn initBits(comptime T: type, out: anytype, num: u16) Bits(T) {
-            const UT = std.meta.Int(.unsigned, @bitSizeOf(T));
-            return .{
-                @bitCast(@as(UT, @intCast(out))),
-                num,
-            };
-        }
-
-        /// Reads `bits` bits from the reader and returns a specified type
-        ///  containing them in the least significant end, returning an error if the
-        ///  specified number of bits could not be read.
-        pub fn readBitsNoEof(self: *@This(), comptime T: type, num: u16) !T {
-            const b, const c = try self.readBitsTuple(T, num);
-            if (c < num) return error.EndOfStream;
-            return b;
-        }
-
-        /// Reads `bits` bits from the reader and returns a specified type
-        ///  containing them in the least significant end. The number of bits successfully
-        ///  read is placed in `out_bits`, as reaching the end of the stream is not an error.
-        pub fn readBits(self: *@This(), comptime T: type, num: u16, out_bits: *u16) !T {
-            const b, const c = try self.readBitsTuple(T, num);
-            out_bits.* = c;
-            return b;
-        }
-
-        /// Reads `bits` bits from the reader and returns a tuple of the specified type
-        ///  containing them in the least significant end, and the number of bits successfully
-        ///  read. Reaching the end of the stream is not an error.
-        pub fn readBitsTuple(self: *@This(), comptime T: type, num: u16) !Bits(T) {
-            const UT = std.meta.Int(.unsigned, @bitSizeOf(T));
-            const U = if (@bitSizeOf(T) < 8) u8 else UT; //it is a pain to work with <u8
-
-            //dump any bits in our buffer first
-            if (num <= self.count) return initBits(T, self.removeBits(@intCast(num)), num);
-
-            var out_count: u16 = self.count;
-            var out: U = self.removeBits(self.count);
-
-            //grab all the full bytes we need and put their
-            //bits where they belong
-            const full_bytes_left = (num - out_count) / 8;
-
-            for (0..full_bytes_left) |_| {
-                const byte = self.reader.readByte() catch |err| switch (err) {
-                    error.EndOfStream => return initBits(T, out, out_count),
-                    else => |e| return e,
-                };
-
-                switch (endian) {
-                    .big => {
-                        if (U == u8) out = 0 else out <<= 8; //shifting u8 by 8 is illegal in Zig
-                        out |= byte;
-                    },
-                    .little => {
-                        const pos = @as(U, byte) << @intCast(out_count);
-                        out |= pos;
-                    },
-                }
-                out_count += 8;
-            }
-
-            const bits_left = num - out_count;
-            const keep = 8 - bits_left;
-
-            if (bits_left == 0) return initBits(T, out, out_count);
-
-            const final_byte = self.reader.readByte() catch |err| switch (err) {
-                error.EndOfStream => return initBits(T, out, out_count),
-                else => |e| return e,
-            };
-
-            switch (endian) {
-                .big => {
-                    out <<= @intCast(bits_left);
-                    out |= final_byte >> @intCast(keep);
-                    self.bits = final_byte & low_bit_mask[keep];
-                },
-                .little => {
-                    const pos = @as(U, final_byte & low_bit_mask[bits_left]) << @intCast(out_count);
-                    out |= pos;
-                    self.bits = final_byte >> @intCast(bits_left);
-                },
-            }
-
-            self.count = @intCast(keep);
-            return initBits(T, out, num);
-        }
-
-        //convenience function for removing bits from
-        //the appropriate part of the buffer based on
-        //endianess.
-        fn removeBits(self: *@This(), num: u4) u8 {
-            if (num == 8) {
-                self.count = 0;
-                return self.bits;
-            }
-
-            const keep = self.count - num;
-            const bits = switch (endian) {
-                .big => self.bits >> @intCast(keep),
-                .little => self.bits & low_bit_mask[num],
-            };
-            switch (endian) {
-                .big => self.bits &= low_bit_mask[keep],
-                .little => self.bits >>= @intCast(num),
-            }
-
-            self.count = keep;
-            return bits;
-        }
-
-        pub fn alignToByte(self: *@This()) void {
-            self.bits = 0;
-            self.count = 0;
-        }
-    };
-}
-
-pub fn bitReader(comptime endian: std.builtin.Endian, reader: anytype) BitReader(endian, @TypeOf(reader)) {
-    return .{ .reader = reader };
-}
-
-///////////////////////////////
-
-test "api coverage" {
-    const mem_be = [_]u8{ 0b11001101, 0b00001011 };
-    const mem_le = [_]u8{ 0b00011101, 0b10010101 };
-
-    var mem_in_be = std.io.fixedBufferStream(&mem_be);
-    var bit_stream_be = bitReader(.big, mem_in_be.reader());
-
-    var out_bits: u16 = undefined;
-
-    const expect = std.testing.expect;
-    const expectError = std.testing.expectError;
-
-    try expect(1 == try bit_stream_be.readBits(u2, 1, &out_bits));
-    try expect(out_bits == 1);
-    try expect(2 == try bit_stream_be.readBits(u5, 2, &out_bits));
-    try expect(out_bits == 2);
-    try expect(3 == try bit_stream_be.readBits(u128, 3, &out_bits));
-    try expect(out_bits == 3);
-    try expect(4 == try bit_stream_be.readBits(u8, 4, &out_bits));
-    try expect(out_bits == 4);
-    try expect(5 == try bit_stream_be.readBits(u9, 5, &out_bits));
-    try expect(out_bits == 5);
-    try expect(1 == try bit_stream_be.readBits(u1, 1, &out_bits));
-    try expect(out_bits == 1);
-
-    mem_in_be.pos = 0;
-    bit_stream_be.count = 0;
-    try expect(0b110011010000101 == try bit_stream_be.readBits(u15, 15, &out_bits));
-    try expect(out_bits == 15);
-
-    mem_in_be.pos = 0;
-    bit_stream_be.count = 0;
-    try expect(0b1100110100001011 == try bit_stream_be.readBits(u16, 16, &out_bits));
-    try expect(out_bits == 16);
-
-    _ = try bit_stream_be.readBits(u0, 0, &out_bits);
-
-    try expect(0 == try bit_stream_be.readBits(u1, 1, &out_bits));
-    try expect(out_bits == 0);
-    try expectError(error.EndOfStream, bit_stream_be.readBitsNoEof(u1, 1));
-
-    var mem_in_le = std.io.fixedBufferStream(&mem_le);
-    var bit_stream_le = bitReader(.little, mem_in_le.reader());
-
-    try expect(1 == try bit_stream_le.readBits(u2, 1, &out_bits));
-    try expect(out_bits == 1);
-    try expect(2 == try bit_stream_le.readBits(u5, 2, &out_bits));
-    try expect(out_bits == 2);
-    try expect(3 == try bit_stream_le.readBits(u128, 3, &out_bits));
-    try expect(out_bits == 3);
-    try expect(4 == try bit_stream_le.readBits(u8, 4, &out_bits));
-    try expect(out_bits == 4);
-    try expect(5 == try bit_stream_le.readBits(u9, 5, &out_bits));
-    try expect(out_bits == 5);
-    try expect(1 == try bit_stream_le.readBits(u1, 1, &out_bits));
-    try expect(out_bits == 1);
-
-    mem_in_le.pos = 0;
-    bit_stream_le.count = 0;
-    try expect(0b001010100011101 == try bit_stream_le.readBits(u15, 15, &out_bits));
-    try expect(out_bits == 15);
-
-    mem_in_le.pos = 0;
-    bit_stream_le.count = 0;
-    try expect(0b1001010100011101 == try bit_stream_le.readBits(u16, 16, &out_bits));
-    try expect(out_bits == 16);
-
-    _ = try bit_stream_le.readBits(u0, 0, &out_bits);
-
-    try expect(0 == try bit_stream_le.readBits(u1, 1, &out_bits));
-    try expect(out_bits == 0);
-    try expectError(error.EndOfStream, bit_stream_le.readBitsNoEof(u1, 1));
-}
diff --git a/lib/std/Io/bit_writer.zig b/lib/std/Io/bit_writer.zig
deleted file mode 100644
index eef0ece81b..0000000000
--- a/lib/std/Io/bit_writer.zig
+++ /dev/null
@@ -1,179 +0,0 @@
-const std = @import("../std.zig");
-
-//General note on endianess:
-//Big endian is packed starting in the most significant part of the byte and subsequent
-// bytes contain less significant bits. Thus we write out bits from the high end
-// of our input first.
-//Little endian is packed starting in the least significant part of the byte and
-// subsequent bytes contain more significant bits. Thus we write out bits from
-// the low end of our input first.
-//Regardless of endianess, within any given byte the bits are always in most
-// to least significant order.
-//Also regardless of endianess, the buffer always aligns bits to the low end
-// of the byte.
-
-/// Creates a bit writer which allows for writing bits to an underlying standard writer
-pub fn BitWriter(comptime endian: std.builtin.Endian, comptime Writer: type) type {
-    return struct {
-        writer: Writer,
-        bits: u8 = 0,
-        count: u4 = 0,
-
-        const low_bit_mask = [9]u8{
-            0b00000000,
-            0b00000001,
-            0b00000011,
-            0b00000111,
-            0b00001111,
-            0b00011111,
-            0b00111111,
-            0b01111111,
-            0b11111111,
-        };
-
-        /// Write the specified number of bits to the writer from the least significant bits of
-        ///  the specified value. Bits will only be written to the writer when there
-        ///  are enough to fill a byte.
-        pub fn writeBits(self: *@This(), value: anytype, num: u16) !void {
-            const T = @TypeOf(value);
-            const UT = std.meta.Int(.unsigned, @bitSizeOf(T));
-            const U = if (@bitSizeOf(T) < 8) u8 else UT; //<u8 is a pain to work with
-
-            var in: U = @as(UT, @bitCast(value));
-            var in_count: u16 = num;
-
-            if (self.count > 0) {
-                //if we can't fill the buffer, add what we have
-                const bits_free = 8 - self.count;
-                if (num < bits_free) {
-                    self.addBits(@truncate(in), @intCast(num));
-                    return;
-                }
-
-                //finish filling the buffer and flush it
-                if (num == bits_free) {
-                    self.addBits(@truncate(in), @intCast(num));
-                    return self.flushBits();
-                }
-
-                switch (endian) {
-                    .big => {
-                        const bits = in >> @intCast(in_count - bits_free);
-                        self.addBits(@truncate(bits), bits_free);
-                    },
-                    .little => {
-                        self.addBits(@truncate(in), bits_free);
-                        in >>= @intCast(bits_free);
-                    },
-                }
-                in_count -= bits_free;
-                try self.flushBits();
-            }
-
-            //write full bytes while we can
-            const full_bytes_left = in_count / 8;
-            for (0..full_bytes_left) |_| {
-                switch (endian) {
-                    .big => {
-                        const bits = in >> @intCast(in_count - 8);
-                        try self.writer.writeByte(@truncate(bits));
-                    },
-                    .little => {
-                        try self.writer.writeByte(@truncate(in));
-                        if (U == u8) in = 0 else in >>= 8;
-                    },
-                }
-                in_count -= 8;
-            }
-
-            //save the remaining bits in the buffer
-            self.addBits(@truncate(in), @intCast(in_count));
-        }
-
-        //convenience funciton for adding bits to the buffer
-        //in the appropriate position based on endianess
-        fn addBits(self: *@This(), bits: u8, num: u4) void {
-            if (num == 8) self.bits = bits else switch (endian) {
-                .big => {
-                    self.bits <<= @intCast(num);
-                    self.bits |= bits & low_bit_mask[num];
-                },
-                .little => {
-                    const pos = bits << @intCast(self.count);
-                    self.bits |= pos;
-                },
-            }
-            self.count += num;
-        }
-
-        /// Flush any remaining bits to the writer, filling
-        /// unused bits with 0s.
-        pub fn flushBits(self: *@This()) !void {
-            if (self.count == 0) return;
-            if (endian == .big) self.bits <<= @intCast(8 - self.count);
-            try self.writer.writeByte(self.bits);
-            self.bits = 0;
-            self.count = 0;
-        }
-    };
-}
-
-pub fn bitWriter(comptime endian: std.builtin.Endian, writer: anytype) BitWriter(endian, @TypeOf(writer)) {
-    return .{ .writer = writer };
-}
-
-///////////////////////////////
-
-test "api coverage" {
-    var mem_be = [_]u8{0} ** 2;
-    var mem_le = [_]u8{0} ** 2;
-
-    var mem_out_be = std.io.fixedBufferStream(&mem_be);
-    var bit_stream_be = bitWriter(.big, mem_out_be.writer());
-
-    const testing = std.testing;
-
-    try bit_stream_be.writeBits(@as(u2, 1), 1);
-    try bit_stream_be.writeBits(@as(u5, 2), 2);
-    try bit_stream_be.writeBits(@as(u128, 3), 3);
-    try bit_stream_be.writeBits(@as(u8, 4), 4);
-    try bit_stream_be.writeBits(@as(u9, 5), 5);
-    try bit_stream_be.writeBits(@as(u1, 1), 1);
-
-    try testing.expect(mem_be[0] == 0b11001101 and mem_be[1] == 0b00001011);
-
-    mem_out_be.pos = 0;
-
-    try bit_stream_be.writeBits(@as(u15, 0b110011010000101), 15);
-    try bit_stream_be.flushBits();
-    try testing.expect(mem_be[0] == 0b11001101 and mem_be[1] == 0b00001010);
-
-    mem_out_be.pos = 0;
-    try bit_stream_be.writeBits(@as(u32, 0b110011010000101), 16);
-    try testing.expect(mem_be[0] == 0b01100110 and mem_be[1] == 0b10000101);
-
-    try bit_stream_be.writeBits(@as(u0, 0), 0);
-
-    var mem_out_le = std.io.fixedBufferStream(&mem_le);
-    var bit_stream_le = bitWriter(.little, mem_out_le.writer());
-
-    try bit_stream_le.writeBits(@as(u2, 1), 1);
-    try bit_stream_le.writeBits(@as(u5, 2), 2);
-    try bit_stream_le.writeBits(@as(u128, 3), 3);
-    try bit_stream_le.writeBits(@as(u8, 4), 4);
-    try bit_stream_le.writeBits(@as(u9, 5), 5);
-    try bit_stream_le.writeBits(@as(u1, 1), 1);
-
-    try testing.expect(mem_le[0] == 0b00011101 and mem_le[1] == 0b10010101);
-
-    mem_out_le.pos = 0;
-    try bit_stream_le.writeBits(@as(u15, 0b110011010000101), 15);
-    try bit_stream_le.flushBits();
-    try testing.expect(mem_le[0] == 0b10000101 and mem_le[1] == 0b01100110);
-
-    mem_out_le.pos = 0;
-    try bit_stream_le.writeBits(@as(u32, 0b1100110100001011), 16);
-    try testing.expect(mem_le[0] == 0b00001011 and mem_le[1] == 0b11001101);
-
-    try bit_stream_le.writeBits(@as(u0, 0), 0);
-}
diff --git a/lib/std/Io/fixed_buffer_stream.zig b/lib/std/Io/fixed_buffer_stream.zig
index 67d6f3d286..c284b9baf4 100644
--- a/lib/std/Io/fixed_buffer_stream.zig
+++ b/lib/std/Io/fixed_buffer_stream.zig
@@ -4,8 +4,7 @@ const testing = std.testing;
 const mem = std.mem;
 const assert = std.debug.assert;
 
-/// This turns a byte buffer into an `io.GenericWriter`, `io.GenericReader`, or `io.SeekableStream`.
-/// If the supplied byte buffer is const, then `io.GenericWriter` is not available.
+/// Deprecated in favor of `std.Io.Reader.fixed` and `std.Io.Writer.fixed`.
 pub fn FixedBufferStream(comptime Buffer: type) type {
     return struct {
         /// `Buffer` is either a `[]u8` or `[]const u8`.
@@ -20,16 +19,6 @@ pub fn FixedBufferStream(comptime Buffer: type) type {
         pub const Reader = io.GenericReader(*Self, ReadError, read);
         pub const Writer = io.GenericWriter(*Self, WriteError, write);
 
-        pub const SeekableStream = io.SeekableStream(
-            *Self,
-            SeekError,
-            GetSeekPosError,
-            seekTo,
-            seekBy,
-            getPos,
-            getEndPos,
-        );
-
         const Self = @This();
 
         pub fn reader(self: *Self) Reader {
@@ -40,10 +29,6 @@ pub fn FixedBufferStream(comptime Buffer: type) type {
             return .{ .context = self };
         }
 
-        pub fn seekableStream(self: *Self) SeekableStream {
-            return .{ .context = self };
-        }
-
         pub fn read(self: *Self, dest: []u8) ReadError!usize {
             const size = @min(dest.len, self.buffer.len - self.pos);
             const end = self.pos + size;
diff --git a/lib/std/Io/seekable_stream.zig b/lib/std/Io/seekable_stream.zig
deleted file mode 100644
index 1aa653dbe5..0000000000
--- a/lib/std/Io/seekable_stream.zig
+++ /dev/null
@@ -1,35 +0,0 @@
-const std = @import("../std.zig");
-
-pub fn SeekableStream(
-    comptime Context: type,
-    comptime SeekErrorType: type,
-    comptime GetSeekPosErrorType: type,
-    comptime seekToFn: fn (context: Context, pos: u64) SeekErrorType!void,
-    comptime seekByFn: fn (context: Context, pos: i64) SeekErrorType!void,
-    comptime getPosFn: fn (context: Context) GetSeekPosErrorType!u64,
-    comptime getEndPosFn: fn (context: Context) GetSeekPosErrorType!u64,
-) type {
-    return struct {
-        context: Context,
-
-        const Self = @This();
-        pub const SeekError = SeekErrorType;
-        pub const GetSeekPosError = GetSeekPosErrorType;
-
-        pub fn seekTo(self: Self, pos: u64) SeekError!void {
-            return seekToFn(self.context, pos);
-        }
-
-        pub fn seekBy(self: Self, amt: i64) SeekError!void {
-            return seekByFn(self.context, amt);
-        }
-
-        pub fn getEndPos(self: Self) GetSeekPosError!u64 {
-            return getEndPosFn(self.context);
-        }
-
-        pub fn getPos(self: Self) GetSeekPosError!u64 {
-            return getPosFn(self.context);
-        }
-    };
-}
diff --git a/lib/std/Io/test.zig b/lib/std/Io/test.zig
index c08879316e..e0fcea7674 100644
--- a/lib/std/Io/test.zig
+++ b/lib/std/Io/test.zig
@@ -57,51 +57,6 @@ test "write a file, read it, then delete it" {
     try tmp.dir.deleteFile(tmp_file_name);
 }
 
-test "BitStreams with File Stream" {
-    var tmp = tmpDir(.{});
-    defer tmp.cleanup();
-
-    const tmp_file_name = "temp_test_file.txt";
-    {
-        var file = try tmp.dir.createFile(tmp_file_name, .{});
-        defer file.close();
-
-        var bit_stream = io.bitWriter(native_endian, file.deprecatedWriter());
-
-        try bit_stream.writeBits(@as(u2, 1), 1);
-        try bit_stream.writeBits(@as(u5, 2), 2);
-        try bit_stream.writeBits(@as(u128, 3), 3);
-        try bit_stream.writeBits(@as(u8, 4), 4);
-        try bit_stream.writeBits(@as(u9, 5), 5);
-        try bit_stream.writeBits(@as(u1, 1), 1);
-        try bit_stream.flushBits();
-    }
-    {
-        var file = try tmp.dir.openFile(tmp_file_name, .{});
-        defer file.close();
-
-        var bit_stream = io.bitReader(native_endian, file.deprecatedReader());
-
-        var out_bits: u16 = undefined;
-
-        try expect(1 == try bit_stream.readBits(u2, 1, &out_bits));
-        try expect(out_bits == 1);
-        try expect(2 == try bit_stream.readBits(u5, 2, &out_bits));
-        try expect(out_bits == 2);
-        try expect(3 == try bit_stream.readBits(u128, 3, &out_bits));
-        try expect(out_bits == 3);
-        try expect(4 == try bit_stream.readBits(u8, 4, &out_bits));
-        try expect(out_bits == 4);
-        try expect(5 == try bit_stream.readBits(u9, 5, &out_bits));
-        try expect(out_bits == 5);
-        try expect(1 == try bit_stream.readBits(u1, 1, &out_bits));
-        try expect(out_bits == 1);
-
-        try expectError(error.EndOfStream, bit_stream.readBitsNoEof(u1, 1));
-    }
-    try tmp.dir.deleteFile(tmp_file_name);
-}
-
 test "File seek ops" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();
diff --git a/lib/std/compress.zig b/lib/std/compress.zig
index 018de51001..199d046af6 100644
--- a/lib/std/compress.zig
+++ b/lib/std/compress.zig
@@ -1,8 +1,7 @@
 //! Compression algorithms.
 
+/// gzip and zlib are here.
 pub const flate = @import("compress/flate.zig");
-pub const gzip = @import("compress/gzip.zig");
-pub const zlib = @import("compress/zlib.zig");
 pub const lzma = @import("compress/lzma.zig");
 pub const lzma2 = @import("compress/lzma2.zig");
 pub const xz = @import("compress/xz.zig");
@@ -14,6 +13,4 @@ test {
     _ = lzma2;
     _ = xz;
     _ = zstd;
-    _ = gzip;
-    _ = zlib;
 }
diff --git a/lib/std/compress/flate.zig b/lib/std/compress/flate.zig
index 6a111ac0fc..4391a06787 100644
--- a/lib/std/compress/flate.zig
+++ b/lib/std/compress/flate.zig
@@ -1,477 +1,180 @@
+const std = @import("../std.zig");
+
+/// When decompressing, the output buffer is used as the history window, so
+/// less than this may result in failure to decompress streams that were
+/// compressed with a larger window.
+pub const max_window_len = history_len * 2;
+
+pub const history_len = 32768;
+
 /// Deflate is a lossless data compression file format that uses a combination
 /// of LZ77 and Huffman coding.
-pub const deflate = @import("flate/deflate.zig");
+pub const Compress = @import("flate/Compress.zig");
 
-/// Inflate is the decoding process that takes a Deflate bitstream for
-/// decompression and correctly produces the original full-size data or file.
-pub const inflate = @import("flate/inflate.zig");
+/// Inflate is the decoding process that consumes a Deflate bitstream and
+/// produces the original full-size data.
+pub const Decompress = @import("flate/Decompress.zig");
 
-/// Decompress compressed data from reader and write plain data to the writer.
-pub fn decompress(reader: anytype, writer: anytype) !void {
-    try inflate.decompress(.raw, reader, writer);
-}
+/// Compression without Lempel-Ziv match searching. Faster compression, less
+/// memory requirements but bigger compressed sizes.
+pub const HuffmanEncoder = @import("flate/HuffmanEncoder.zig");
 
-/// Decompressor type
-pub fn Decompressor(comptime ReaderType: type) type {
-    return inflate.Decompressor(.raw, ReaderType);
-}
+/// Container of the deflate bit stream body. Container adds header before
+/// deflate bit stream and footer after. It can bi gzip, zlib or raw (no header,
+/// no footer, raw bit stream).
+///
+/// Zlib format is defined in rfc 1950. Header has 2 bytes and footer 4 bytes
+/// addler 32 checksum.
+///
+/// Gzip format is defined in rfc 1952. Header has 10+ bytes and footer 4 bytes
+/// crc32 checksum and 4 bytes of uncompressed data length.
+///
+/// rfc 1950: https://datatracker.ietf.org/doc/html/rfc1950#page-4
+/// rfc 1952: https://datatracker.ietf.org/doc/html/rfc1952#page-5
+pub const Container = enum {
+    raw, // no header or footer
+    gzip, // gzip header and footer
+    zlib, // zlib header and footer
 
-/// Create Decompressor which will read compressed data from reader.
-pub fn decompressor(reader: anytype) Decompressor(@TypeOf(reader)) {
-    return inflate.decompressor(.raw, reader);
-}
-
-/// Compression level, trades between speed and compression size.
-pub const Options = deflate.Options;
-
-/// Compress plain data from reader and write compressed data to the writer.
-pub fn compress(reader: anytype, writer: anytype, options: Options) !void {
-    try deflate.compress(.raw, reader, writer, options);
-}
-
-/// Compressor type
-pub fn Compressor(comptime WriterType: type) type {
-    return deflate.Compressor(.raw, WriterType);
-}
-
-/// Create Compressor which outputs compressed data to the writer.
-pub fn compressor(writer: anytype, options: Options) !Compressor(@TypeOf(writer)) {
-    return try deflate.compressor(.raw, writer, options);
-}
-
-/// Huffman only compression. Without Lempel-Ziv match searching. Faster
-/// compression, less memory requirements but bigger compressed sizes.
-pub const huffman = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.huffman.compress(.raw, reader, writer);
+    pub fn size(w: Container) usize {
+        return headerSize(w) + footerSize(w);
     }
 
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.huffman.Compressor(.raw, WriterType);
+    pub fn headerSize(w: Container) usize {
+        return header(w).len;
     }
 
-    pub fn compressor(writer: anytype) !huffman.Compressor(@TypeOf(writer)) {
-        return deflate.huffman.compressor(.raw, writer);
-    }
-};
-
-// No compression store only. Compressed size is slightly bigger than plain.
-pub const store = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.store.compress(.raw, reader, writer);
+    pub fn footerSize(w: Container) usize {
+        return switch (w) {
+            .gzip => 8,
+            .zlib => 4,
+            .raw => 0,
+        };
     }
 
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.store.Compressor(.raw, WriterType);
-    }
+    pub const list = [_]Container{ .raw, .gzip, .zlib };
 
-    pub fn compressor(writer: anytype) !store.Compressor(@TypeOf(writer)) {
-        return deflate.store.compressor(.raw, writer);
-    }
-};
-
-/// Container defines header/footer around deflate bit stream. Gzip and zlib
-/// compression algorithms are containers around deflate bit stream body.
-const Container = @import("flate/container.zig").Container;
-const std = @import("std");
-const testing = std.testing;
-const fixedBufferStream = std.io.fixedBufferStream;
-const print = std.debug.print;
-const builtin = @import("builtin");
-
-test {
-    _ = deflate;
-    _ = inflate;
-}
-
-test "compress/decompress" {
-    var cmp_buf: [64 * 1024]u8 = undefined; // compressed data buffer
-    var dcm_buf: [64 * 1024]u8 = undefined; // decompressed data buffer
-
-    const levels = [_]deflate.Level{ .level_4, .level_5, .level_6, .level_7, .level_8, .level_9 };
-    const cases = [_]struct {
-        data: []const u8, // uncompressed content
-        // compressed data sizes per level 4-9
-        gzip_sizes: [levels.len]usize = [_]usize{0} ** levels.len,
-        huffman_only_size: usize = 0,
-        store_size: usize = 0,
-    }{
-        .{
-            .data = @embedFile("flate/testdata/rfc1951.txt"),
-            .gzip_sizes = [_]usize{ 11513, 11217, 11139, 11126, 11122, 11119 },
-            .huffman_only_size = 20287,
-            .store_size = 36967,
-        },
-        .{
-            .data = @embedFile("flate/testdata/fuzz/roundtrip1.input"),
-            .gzip_sizes = [_]usize{ 373, 370, 370, 370, 370, 370 },
-            .huffman_only_size = 393,
-            .store_size = 393,
-        },
-        .{
-            .data = @embedFile("flate/testdata/fuzz/roundtrip2.input"),
-            .gzip_sizes = [_]usize{ 373, 373, 373, 373, 373, 373 },
-            .huffman_only_size = 394,
-            .store_size = 394,
-        },
-        .{
-            .data = @embedFile("flate/testdata/fuzz/deflate-stream.expect"),
-            .gzip_sizes = [_]usize{ 351, 347, 347, 347, 347, 347 },
-            .huffman_only_size = 498,
-            .store_size = 747,
-        },
+    pub const Error = error{
+        BadGzipHeader,
+        BadZlibHeader,
+        WrongGzipChecksum,
+        WrongGzipSize,
+        WrongZlibChecksum,
     };
 
-    for (cases, 0..) |case, case_no| { // for each case
-        const data = case.data;
+    pub fn header(container: Container) []const u8 {
+        return switch (container) {
+            // GZIP 10 byte header (https://datatracker.ietf.org/doc/html/rfc1952#page-5):
+            //  - ID1 (IDentification 1), always 0x1f
+            //  - ID2 (IDentification 2), always 0x8b
+            //  - CM (Compression Method), always 8 = deflate
+            //  - FLG (Flags), all set to 0
+            //  - 4 bytes, MTIME (Modification time), not used, all set to zero
+            //  - XFL (eXtra FLags), all set to zero
+            //  - OS (Operating System), 03 = Unix
+            .gzip => &[_]u8{ 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03 },
+            // ZLIB has a two-byte header (https://datatracker.ietf.org/doc/html/rfc1950#page-4):
+            // 1st byte:
+            //  - First four bits is the CINFO (compression info), which is 7 for the default deflate window size.
+            //  - The next four bits is the CM (compression method), which is 8 for deflate.
+            // 2nd byte:
+            //  - Two bits is the FLEVEL (compression level). Values are: 0=fastest, 1=fast, 2=default, 3=best.
+            //  - The next bit, FDICT, is set if a dictionary is given.
+            //  - The final five FCHECK bits form a mod-31 checksum.
+            //
+            // CINFO = 7, CM = 8, FLEVEL = 0b10, FDICT = 0, FCHECK = 0b11100
+            .zlib => &[_]u8{ 0x78, 0b10_0_11100 },
+            .raw => &.{},
+        };
+    }
 
-        for (levels, 0..) |level, i| { // for each compression level
+    pub const Hasher = union(Container) {
+        raw: void,
+        gzip: struct {
+            crc: std.hash.Crc32 = .init(),
+            count: u32 = 0,
+        },
+        zlib: std.hash.Adler32,
 
-            inline for (Container.list) |container| { // for each wrapping
-                var compressed_size: usize = if (case.gzip_sizes[i] > 0)
-                    case.gzip_sizes[i] - Container.gzip.size() + container.size()
-                else
-                    0;
-
-                // compress original stream to compressed stream
-                {
-                    var original = fixedBufferStream(data);
-                    var compressed = fixedBufferStream(&cmp_buf);
-                    try deflate.compress(container, original.reader(), compressed.writer(), .{ .level = level });
-                    if (compressed_size == 0) {
-                        if (container == .gzip)
-                            print("case {d} gzip level {} compressed size: {d}\n", .{ case_no, level, compressed.pos });
-                        compressed_size = compressed.pos;
-                    }
-                    try testing.expectEqual(compressed_size, compressed.pos);
-                }
-                // decompress compressed stream to decompressed stream
-                {
-                    var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
-                    var decompressed = fixedBufferStream(&dcm_buf);
-                    try inflate.decompress(container, compressed.reader(), decompressed.writer());
-                    try testing.expectEqualSlices(u8, data, decompressed.getWritten());
-                }
-
-                // compressor writer interface
-                {
-                    var compressed = fixedBufferStream(&cmp_buf);
-                    var cmp = try deflate.compressor(container, compressed.writer(), .{ .level = level });
-                    var cmp_wrt = cmp.writer();
-                    try cmp_wrt.writeAll(data);
-                    try cmp.finish();
-
-                    try testing.expectEqual(compressed_size, compressed.pos);
-                }
-                // decompressor reader interface
-                {
-                    var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
-                    var dcm = inflate.decompressor(container, compressed.reader());
-                    var dcm_rdr = dcm.reader();
-                    const n = try dcm_rdr.readAll(&dcm_buf);
-                    try testing.expectEqual(data.len, n);
-                    try testing.expectEqualSlices(u8, data, dcm_buf[0..n]);
-                }
-            }
+        pub fn init(containter: Container) Hasher {
+            return switch (containter) {
+                .gzip => .{ .gzip = .{} },
+                .zlib => .{ .zlib = .{} },
+                .raw => .raw,
+            };
         }
-        // huffman only compression
-        {
-            inline for (Container.list) |container| { // for each wrapping
-                var compressed_size: usize = if (case.huffman_only_size > 0)
-                    case.huffman_only_size - Container.gzip.size() + container.size()
-                else
-                    0;
 
-                // compress original stream to compressed stream
-                {
-                    var original = fixedBufferStream(data);
-                    var compressed = fixedBufferStream(&cmp_buf);
-                    var cmp = try deflate.huffman.compressor(container, compressed.writer());
-                    try cmp.compress(original.reader());
-                    try cmp.finish();
-                    if (compressed_size == 0) {
-                        if (container == .gzip)
-                            print("case {d} huffman only compressed size: {d}\n", .{ case_no, compressed.pos });
-                        compressed_size = compressed.pos;
-                    }
-                    try testing.expectEqual(compressed_size, compressed.pos);
-                }
-                // decompress compressed stream to decompressed stream
-                {
-                    var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
-                    var decompressed = fixedBufferStream(&dcm_buf);
-                    try inflate.decompress(container, compressed.reader(), decompressed.writer());
-                    try testing.expectEqualSlices(u8, data, decompressed.getWritten());
-                }
+        pub fn container(h: Hasher) Container {
+            return h;
+        }
+
+        pub fn update(h: *Hasher, buf: []const u8) void {
+            switch (h.*) {
+                .raw => {},
+                .gzip => |*gzip| {
+                    gzip.update(buf);
+                    gzip.count +%= buf.len;
+                },
+                .zlib => |*zlib| {
+                    zlib.update(buf);
+                },
+                inline .gzip, .zlib => |*x| x.update(buf),
             }
         }
 
-        // store only
-        {
-            inline for (Container.list) |container| { // for each wrapping
-                var compressed_size: usize = if (case.store_size > 0)
-                    case.store_size - Container.gzip.size() + container.size()
-                else
-                    0;
+        pub fn writeFooter(hasher: *Hasher, writer: *std.Io.Writer) std.Io.Writer.Error!void {
+            var bits: [4]u8 = undefined;
+            switch (hasher.*) {
+                .gzip => |*gzip| {
+                    // GZIP 8 bytes footer
+                    //  - 4 bytes, CRC32 (CRC-32)
+                    //  - 4 bytes, ISIZE (Input SIZE) - size of the original (uncompressed) input data modulo 2^32
+                    std.mem.writeInt(u32, &bits, gzip.final(), .little);
+                    try writer.writeAll(&bits);
 
-                // compress original stream to compressed stream
-                {
-                    var original = fixedBufferStream(data);
-                    var compressed = fixedBufferStream(&cmp_buf);
-                    var cmp = try deflate.store.compressor(container, compressed.writer());
-                    try cmp.compress(original.reader());
-                    try cmp.finish();
-                    if (compressed_size == 0) {
-                        if (container == .gzip)
-                            print("case {d} store only compressed size: {d}\n", .{ case_no, compressed.pos });
-                        compressed_size = compressed.pos;
-                    }
-
-                    try testing.expectEqual(compressed_size, compressed.pos);
-                }
-                // decompress compressed stream to decompressed stream
-                {
-                    var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
-                    var decompressed = fixedBufferStream(&dcm_buf);
-                    try inflate.decompress(container, compressed.reader(), decompressed.writer());
-                    try testing.expectEqualSlices(u8, data, decompressed.getWritten());
-                }
+                    std.mem.writeInt(u32, &bits, gzip.bytes_read, .little);
+                    try writer.writeAll(&bits);
+                },
+                .zlib => |*zlib| {
+                    // ZLIB (RFC 1950) is big-endian, unlike GZIP (RFC 1952).
+                    // 4 bytes of ADLER32 (Adler-32 checksum)
+                    // Checksum value of the uncompressed data (excluding any
+                    // dictionary data) computed according to Adler-32
+                    // algorithm.
+                    std.mem.writeInt(u32, &bits, zlib.final, .big);
+                    try writer.writeAll(&bits);
+                },
+                .raw => {},
             }
         }
-    }
-}
+    };
 
-fn testDecompress(comptime container: Container, compressed: []const u8, expected_plain: []const u8) !void {
-    var in = fixedBufferStream(compressed);
-    var out = std.ArrayList(u8).init(testing.allocator);
-    defer out.deinit();
+    pub const Metadata = union(Container) {
+        raw: void,
+        gzip: struct {
+            crc: u32 = 0,
+            count: u32 = 0,
+        },
+        zlib: struct {
+            adler: u32 = 0,
+        },
 
-    try inflate.decompress(container, in.reader(), out.writer());
-    try testing.expectEqualSlices(u8, expected_plain, out.items);
-}
-
-test "don't read past deflate stream's end" {
-    try testDecompress(.zlib, &[_]u8{
-        0x08, 0xd7, 0x63, 0xf8, 0xcf, 0xc0, 0xc0, 0x00, 0xc1, 0xff,
-        0xff, 0x43, 0x30, 0x03, 0x03, 0xc3, 0xff, 0xff, 0xff, 0x01,
-        0x83, 0x95, 0x0b, 0xf5,
-    }, &[_]u8{
-        0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
-        0x00, 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
-        0x00, 0x00, 0xff, 0xff, 0xff,
-    });
-}
-
-test "zlib header" {
-    // Truncated header
-    try testing.expectError(
-        error.EndOfStream,
-        testDecompress(.zlib, &[_]u8{0x78}, ""),
-    );
-    // Wrong CM
-    try testing.expectError(
-        error.BadZlibHeader,
-        testDecompress(.zlib, &[_]u8{ 0x79, 0x94 }, ""),
-    );
-    // Wrong CINFO
-    try testing.expectError(
-        error.BadZlibHeader,
-        testDecompress(.zlib, &[_]u8{ 0x88, 0x98 }, ""),
-    );
-    // Wrong checksum
-    try testing.expectError(
-        error.WrongZlibChecksum,
-        testDecompress(.zlib, &[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00 }, ""),
-    );
-    // Truncated checksum
-    try testing.expectError(
-        error.EndOfStream,
-        testDecompress(.zlib, &[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00 }, ""),
-    );
-}
-
-test "gzip header" {
-    // Truncated header
-    try testing.expectError(
-        error.EndOfStream,
-        testDecompress(.gzip, &[_]u8{ 0x1f, 0x8B }, undefined),
-    );
-    // Wrong CM
-    try testing.expectError(
-        error.BadGzipHeader,
-        testDecompress(.gzip, &[_]u8{
-            0x1f, 0x8b, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x03,
-        }, undefined),
-    );
-
-    // Wrong checksum
-    try testing.expectError(
-        error.WrongGzipChecksum,
-        testDecompress(.gzip, &[_]u8{
-            0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01,
-            0x00, 0x00, 0x00, 0x00,
-        }, undefined),
-    );
-    // Truncated checksum
-    try testing.expectError(
-        error.EndOfStream,
-        testDecompress(.gzip, &[_]u8{
-            0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00,
-        }, undefined),
-    );
-    // Wrong initial size
-    try testing.expectError(
-        error.WrongGzipSize,
-        testDecompress(.gzip, &[_]u8{
-            0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x00, 0x00, 0x01,
-        }, undefined),
-    );
-    // Truncated initial size field
-    try testing.expectError(
-        error.EndOfStream,
-        testDecompress(.gzip, &[_]u8{
-            0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x00, 0x00,
-        }, undefined),
-    );
-
-    try testDecompress(.gzip, &[_]u8{
-        // GZIP header
-        0x1f, 0x8b, 0x08, 0x12, 0x00, 0x09, 0x6e, 0x88, 0x00, 0xff, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x00,
-        // header.FHCRC (should cover entire header)
-        0x99, 0xd6,
-        // GZIP data
-        0x01, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-    }, "");
-}
-
-test "public interface" {
-    const plain_data = [_]u8{ 'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a };
-
-    // deflate final stored block, header + plain (stored) data
-    const deflate_block = [_]u8{
-        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
-    } ++ plain_data;
-
-    // gzip header/footer + deflate block
-    const gzip_data =
-        [_]u8{ 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03 } ++ // gzip header (10 bytes)
-        deflate_block ++
-        [_]u8{ 0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00 }; // gzip footer checksum (4 byte), size (4 bytes)
-
-    // zlib header/footer + deflate block
-    const zlib_data = [_]u8{ 0x78, 0b10_0_11100 } ++ // zlib header (2 bytes)}
-        deflate_block ++
-        [_]u8{ 0x1c, 0xf2, 0x04, 0x47 }; // zlib footer: checksum
-
-    const gzip = @import("gzip.zig");
-    const zlib = @import("zlib.zig");
-    const flate = @This();
-
-    try testInterface(gzip, &gzip_data, &plain_data);
-    try testInterface(zlib, &zlib_data, &plain_data);
-    try testInterface(flate, &deflate_block, &plain_data);
-}
-
-fn testInterface(comptime pkg: type, gzip_data: []const u8, plain_data: []const u8) !void {
-    var buffer1: [64]u8 = undefined;
-    var buffer2: [64]u8 = undefined;
-
-    var compressed = fixedBufferStream(&buffer1);
-    var plain = fixedBufferStream(&buffer2);
-
-    // decompress
-    {
-        var in = fixedBufferStream(gzip_data);
-        try pkg.decompress(in.reader(), plain.writer());
-        try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
-    }
-    plain.reset();
-    compressed.reset();
-
-    // compress/decompress
-    {
-        var in = fixedBufferStream(plain_data);
-        try pkg.compress(in.reader(), compressed.writer(), .{});
-        compressed.reset();
-        try pkg.decompress(compressed.reader(), plain.writer());
-        try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
-    }
-    plain.reset();
-    compressed.reset();
-
-    // compressor/decompressor
-    {
-        var in = fixedBufferStream(plain_data);
-        var cmp = try pkg.compressor(compressed.writer(), .{});
-        try cmp.compress(in.reader());
-        try cmp.finish();
-
-        compressed.reset();
-        var dcp = pkg.decompressor(compressed.reader());
-        try dcp.decompress(plain.writer());
-        try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
-    }
-    plain.reset();
-    compressed.reset();
-
-    // huffman
-    {
-        // huffman compress/decompress
-        {
-            var in = fixedBufferStream(plain_data);
-            try pkg.huffman.compress(in.reader(), compressed.writer());
-            compressed.reset();
-            try pkg.decompress(compressed.reader(), plain.writer());
-            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
+        pub fn init(containter: Container) Metadata {
+            return switch (containter) {
+                .gzip => .{ .gzip = .{} },
+                .zlib => .{ .zlib = .{} },
+                .raw => .raw,
+            };
         }
-        plain.reset();
-        compressed.reset();
 
-        // huffman compressor/decompressor
-        {
-            var in = fixedBufferStream(plain_data);
-            var cmp = try pkg.huffman.compressor(compressed.writer());
-            try cmp.compress(in.reader());
-            try cmp.finish();
-
-            compressed.reset();
-            try pkg.decompress(compressed.reader(), plain.writer());
-            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
+        pub fn container(m: Metadata) Container {
+            return m;
         }
-    }
-    plain.reset();
-    compressed.reset();
+    };
+};
 
-    // store
-    {
-        // store compress/decompress
-        {
-            var in = fixedBufferStream(plain_data);
-            try pkg.store.compress(in.reader(), compressed.writer());
-            compressed.reset();
-            try pkg.decompress(compressed.reader(), plain.writer());
-            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
-        }
-        plain.reset();
-        compressed.reset();
-
-        // store compressor/decompressor
-        {
-            var in = fixedBufferStream(plain_data);
-            var cmp = try pkg.store.compressor(compressed.writer());
-            try cmp.compress(in.reader());
-            try cmp.finish();
-
-            compressed.reset();
-            try pkg.decompress(compressed.reader(), plain.writer());
-            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
-        }
-    }
+test {
+    _ = HuffmanEncoder;
+    _ = Compress;
+    _ = Decompress;
 }
diff --git a/lib/std/compress/flate/BlockWriter.zig b/lib/std/compress/flate/BlockWriter.zig
new file mode 100644
index 0000000000..d0e9dc1203
--- /dev/null
+++ b/lib/std/compress/flate/BlockWriter.zig
@@ -0,0 +1,592 @@
+//! Accepts list of tokens, decides what is best block type to write. What block
+//! type will provide best compression. Writes header and body of the block.
+const std = @import("std");
+const io = std.io;
+const assert = std.debug.assert;
+const Writer = std.io.Writer;
+
+const BlockWriter = @This();
+const flate = @import("../flate.zig");
+const Compress = flate.Compress;
+const HuffmanEncoder = flate.HuffmanEncoder;
+const Token = @import("Token.zig");
+
+const codegen_order = HuffmanEncoder.codegen_order;
+const end_code_mark = 255;
+
+output: *Writer,
+
+codegen_freq: [HuffmanEncoder.codegen_code_count]u16,
+literal_freq: [HuffmanEncoder.max_num_lit]u16,
+distance_freq: [HuffmanEncoder.distance_code_count]u16,
+codegen: [HuffmanEncoder.max_num_lit + HuffmanEncoder.distance_code_count + 1]u8,
+literal_encoding: HuffmanEncoder,
+distance_encoding: HuffmanEncoder,
+codegen_encoding: HuffmanEncoder,
+fixed_literal_encoding: HuffmanEncoder,
+fixed_distance_encoding: HuffmanEncoder,
+huff_distance: HuffmanEncoder,
+
+fixed_literal_codes: [HuffmanEncoder.max_num_frequencies]HuffmanEncoder.Code,
+fixed_distance_codes: [HuffmanEncoder.distance_code_count]HuffmanEncoder.Code,
+distance_codes: [HuffmanEncoder.distance_code_count]HuffmanEncoder.Code,
+
+pub fn init(output: *Writer) BlockWriter {
+    return .{
+        .output = output,
+        .codegen_freq = undefined,
+        .literal_freq = undefined,
+        .distance_freq = undefined,
+        .codegen = undefined,
+        .literal_encoding = undefined,
+        .distance_encoding = undefined,
+        .codegen_encoding = undefined,
+        .fixed_literal_encoding = undefined,
+        .fixed_distance_encoding = undefined,
+        .huff_distance = undefined,
+        .fixed_literal_codes = undefined,
+        .fixed_distance_codes = undefined,
+        .distance_codes = undefined,
+    };
+}
+
+pub fn initBuffers(bw: *BlockWriter) void {
+    bw.fixed_literal_encoding = .fixedLiteralEncoder(&bw.fixed_literal_codes);
+    bw.fixed_distance_encoding = .fixedDistanceEncoder(&bw.fixed_distance_codes);
+    bw.huff_distance = .huffmanDistanceEncoder(&bw.distance_codes);
+}
+
+/// Flush intrenal bit buffer to the writer.
+/// Should be called only when bit stream is at byte boundary.
+///
+/// That is after final block; when last byte could be incomplete or
+/// after stored block; which is aligned to the byte boundary (it has x
+/// padding bits after first 3 bits).
+pub fn flush(self: *BlockWriter) Writer.Error!void {
+    try self.bit_writer.flush();
+}
+
+fn writeCode(self: *BlockWriter, c: Compress.HuffCode) Writer.Error!void {
+    try self.bit_writer.writeBits(c.code, c.len);
+}
+
+/// RFC 1951 3.2.7 specifies a special run-length encoding for specifying
+/// the literal and distance lengths arrays (which are concatenated into a single
+/// array).  This method generates that run-length encoding.
+///
+/// The result is written into the codegen array, and the frequencies
+/// of each code is written into the codegen_freq array.
+/// Codes 0-15 are single byte codes. Codes 16-18 are followed by additional
+/// information. Code bad_code is an end marker
+///
+/// num_literals: The number of literals in literal_encoding
+/// num_distances: The number of distances in distance_encoding
+/// lit_enc: The literal encoder to use
+/// dist_enc: The distance encoder to use
+fn generateCodegen(
+    self: *BlockWriter,
+    num_literals: u32,
+    num_distances: u32,
+    lit_enc: *Compress.LiteralEncoder,
+    dist_enc: *Compress.DistanceEncoder,
+) void {
+    for (self.codegen_freq, 0..) |_, i| {
+        self.codegen_freq[i] = 0;
+    }
+
+    // Note that we are using codegen both as a temporary variable for holding
+    // a copy of the frequencies, and as the place where we put the result.
+    // This is fine because the output is always shorter than the input used
+    // so far.
+    var codegen = &self.codegen; // cache
+    // Copy the concatenated code sizes to codegen. Put a marker at the end.
+    var cgnl = codegen[0..num_literals];
+    for (cgnl, 0..) |_, i| {
+        cgnl[i] = @as(u8, @intCast(lit_enc.codes[i].len));
+    }
+
+    cgnl = codegen[num_literals .. num_literals + num_distances];
+    for (cgnl, 0..) |_, i| {
+        cgnl[i] = @as(u8, @intCast(dist_enc.codes[i].len));
+    }
+    codegen[num_literals + num_distances] = end_code_mark;
+
+    var size = codegen[0];
+    var count: i32 = 1;
+    var out_index: u32 = 0;
+    var in_index: u32 = 1;
+    while (size != end_code_mark) : (in_index += 1) {
+        // INVARIANT: We have seen "count" copies of size that have not yet
+        // had output generated for them.
+        const next_size = codegen[in_index];
+        if (next_size == size) {
+            count += 1;
+            continue;
+        }
+        // We need to generate codegen indicating "count" of size.
+        if (size != 0) {
+            codegen[out_index] = size;
+            out_index += 1;
+            self.codegen_freq[size] += 1;
+            count -= 1;
+            while (count >= 3) {
+                var n: i32 = 6;
+                if (n > count) {
+                    n = count;
+                }
+                codegen[out_index] = 16;
+                out_index += 1;
+                codegen[out_index] = @as(u8, @intCast(n - 3));
+                out_index += 1;
+                self.codegen_freq[16] += 1;
+                count -= n;
+            }
+        } else {
+            while (count >= 11) {
+                var n: i32 = 138;
+                if (n > count) {
+                    n = count;
+                }
+                codegen[out_index] = 18;
+                out_index += 1;
+                codegen[out_index] = @as(u8, @intCast(n - 11));
+                out_index += 1;
+                self.codegen_freq[18] += 1;
+                count -= n;
+            }
+            if (count >= 3) {
+                // 3 <= count <= 10
+                codegen[out_index] = 17;
+                out_index += 1;
+                codegen[out_index] = @as(u8, @intCast(count - 3));
+                out_index += 1;
+                self.codegen_freq[17] += 1;
+                count = 0;
+            }
+        }
+        count -= 1;
+        while (count >= 0) : (count -= 1) {
+            codegen[out_index] = size;
+            out_index += 1;
+            self.codegen_freq[size] += 1;
+        }
+        // Set up invariant for next time through the loop.
+        size = next_size;
+        count = 1;
+    }
+    // Marker indicating the end of the codegen.
+    codegen[out_index] = end_code_mark;
+}
+
+const DynamicSize = struct {
+    size: u32,
+    num_codegens: u32,
+};
+
+/// dynamicSize returns the size of dynamically encoded data in bits.
+fn dynamicSize(
+    self: *BlockWriter,
+    lit_enc: *Compress.LiteralEncoder, // literal encoder
+    dist_enc: *Compress.DistanceEncoder, // distance encoder
+    extra_bits: u32,
+) DynamicSize {
+    var num_codegens = self.codegen_freq.len;
+    while (num_codegens > 4 and self.codegen_freq[codegen_order[num_codegens - 1]] == 0) {
+        num_codegens -= 1;
+    }
+    const header = 3 + 5 + 5 + 4 + (3 * num_codegens) +
+        self.codegen_encoding.bitLength(self.codegen_freq[0..]) +
+        self.codegen_freq[16] * 2 +
+        self.codegen_freq[17] * 3 +
+        self.codegen_freq[18] * 7;
+    const size = header +
+        lit_enc.bitLength(&self.literal_freq) +
+        dist_enc.bitLength(&self.distance_freq) +
+        extra_bits;
+
+    return DynamicSize{
+        .size = @as(u32, @intCast(size)),
+        .num_codegens = @as(u32, @intCast(num_codegens)),
+    };
+}
+
+/// fixedSize returns the size of dynamically encoded data in bits.
+fn fixedSize(self: *BlockWriter, extra_bits: u32) u32 {
+    return 3 +
+        self.fixed_literal_encoding.bitLength(&self.literal_freq) +
+        self.fixed_distance_encoding.bitLength(&self.distance_freq) +
+        extra_bits;
+}
+
+const StoredSize = struct {
+    size: u32,
+    storable: bool,
+};
+
+/// storedSizeFits calculates the stored size, including header.
+/// The function returns the size in bits and whether the block
+/// fits inside a single block.
+fn storedSizeFits(in: ?[]const u8) StoredSize {
+    if (in == null) {
+        return .{ .size = 0, .storable = false };
+    }
+    if (in.?.len <= HuffmanEncoder.max_store_block_size) {
+        return .{ .size = @as(u32, @intCast((in.?.len + 5) * 8)), .storable = true };
+    }
+    return .{ .size = 0, .storable = false };
+}
+
+/// Write the header of a dynamic Huffman block to the output stream.
+///
+///  num_literals: The number of literals specified in codegen
+///  num_distances: The number of distances specified in codegen
+///  num_codegens: The number of codegens used in codegen
+///  eof: Is it the end-of-file? (end of stream)
+fn dynamicHeader(
+    self: *BlockWriter,
+    num_literals: u32,
+    num_distances: u32,
+    num_codegens: u32,
+    eof: bool,
+) Writer.Error!void {
+    const first_bits: u32 = if (eof) 5 else 4;
+    try self.bit_writer.writeBits(first_bits, 3);
+    try self.bit_writer.writeBits(num_literals - 257, 5);
+    try self.bit_writer.writeBits(num_distances - 1, 5);
+    try self.bit_writer.writeBits(num_codegens - 4, 4);
+
+    var i: u32 = 0;
+    while (i < num_codegens) : (i += 1) {
+        const value = self.codegen_encoding.codes[codegen_order[i]].len;
+        try self.bit_writer.writeBits(value, 3);
+    }
+
+    i = 0;
+    while (true) {
+        const code_word: u32 = @as(u32, @intCast(self.codegen[i]));
+        i += 1;
+        if (code_word == end_code_mark) {
+            break;
+        }
+        try self.writeCode(self.codegen_encoding.codes[@as(u32, @intCast(code_word))]);
+
+        switch (code_word) {
+            16 => {
+                try self.bit_writer.writeBits(self.codegen[i], 2);
+                i += 1;
+            },
+            17 => {
+                try self.bit_writer.writeBits(self.codegen[i], 3);
+                i += 1;
+            },
+            18 => {
+                try self.bit_writer.writeBits(self.codegen[i], 7);
+                i += 1;
+            },
+            else => {},
+        }
+    }
+}
+
+fn storedHeader(self: *BlockWriter, length: usize, eof: bool) Writer.Error!void {
+    assert(length <= 65535);
+    const flag: u32 = if (eof) 1 else 0;
+    try self.bit_writer.writeBits(flag, 3);
+    try self.flush();
+    const l: u16 = @intCast(length);
+    try self.bit_writer.writeBits(l, 16);
+    try self.bit_writer.writeBits(~l, 16);
+}
+
+fn fixedHeader(self: *BlockWriter, eof: bool) Writer.Error!void {
+    // Indicate that we are a fixed Huffman block
+    var value: u32 = 2;
+    if (eof) {
+        value = 3;
+    }
+    try self.bit_writer.writeBits(value, 3);
+}
+
+/// Write a block of tokens with the smallest encoding. Will choose block type.
+/// The original input can be supplied, and if the huffman encoded data
+/// is larger than the original bytes, the data will be written as a
+/// stored block.
+/// If the input is null, the tokens will always be Huffman encoded.
+pub fn write(self: *BlockWriter, tokens: []const Token, eof: bool, input: ?[]const u8) Writer.Error!void {
+    const lit_and_dist = self.indexTokens(tokens);
+    const num_literals = lit_and_dist.num_literals;
+    const num_distances = lit_and_dist.num_distances;
+
+    var extra_bits: u32 = 0;
+    const ret = storedSizeFits(input);
+    const stored_size = ret.size;
+    const storable = ret.storable;
+
+    if (storable) {
+        // We only bother calculating the costs of the extra bits required by
+        // the length of distance fields (which will be the same for both fixed
+        // and dynamic encoding), if we need to compare those two encodings
+        // against stored encoding.
+        var length_code: u16 = Token.length_codes_start + 8;
+        while (length_code < num_literals) : (length_code += 1) {
+            // First eight length codes have extra size = 0.
+            extra_bits += @as(u32, @intCast(self.literal_freq[length_code])) *
+                @as(u32, @intCast(Token.lengthExtraBits(length_code)));
+        }
+        var distance_code: u16 = 4;
+        while (distance_code < num_distances) : (distance_code += 1) {
+            // First four distance codes have extra size = 0.
+            extra_bits += @as(u32, @intCast(self.distance_freq[distance_code])) *
+                @as(u32, @intCast(Token.distanceExtraBits(distance_code)));
+        }
+    }
+
+    // Figure out smallest code.
+    // Fixed Huffman baseline.
+    var literal_encoding = &self.fixed_literal_encoding;
+    var distance_encoding = &self.fixed_distance_encoding;
+    var size = self.fixedSize(extra_bits);
+
+    // Dynamic Huffman?
+    var num_codegens: u32 = 0;
+
+    // Generate codegen and codegenFrequencies, which indicates how to encode
+    // the literal_encoding and the distance_encoding.
+    self.generateCodegen(
+        num_literals,
+        num_distances,
+        &self.literal_encoding,
+        &self.distance_encoding,
+    );
+    self.codegen_encoding.generate(self.codegen_freq[0..], 7);
+    const dynamic_size = self.dynamicSize(
+        &self.literal_encoding,
+        &self.distance_encoding,
+        extra_bits,
+    );
+    const dyn_size = dynamic_size.size;
+    num_codegens = dynamic_size.num_codegens;
+
+    if (dyn_size < size) {
+        size = dyn_size;
+        literal_encoding = &self.literal_encoding;
+        distance_encoding = &self.distance_encoding;
+    }
+
+    // Stored bytes?
+    if (storable and stored_size < size) {
+        try self.storedBlock(input.?, eof);
+        return;
+    }
+
+    // Huffman.
+    if (@intFromPtr(literal_encoding) == @intFromPtr(&self.fixed_literal_encoding)) {
+        try self.fixedHeader(eof);
+    } else {
+        try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
+    }
+
+    // Write the tokens.
+    try self.writeTokens(tokens, &literal_encoding.codes, &distance_encoding.codes);
+}
+
+pub fn storedBlock(self: *BlockWriter, input: []const u8, eof: bool) Writer.Error!void {
+    try self.storedHeader(input.len, eof);
+    try self.bit_writer.writeBytes(input);
+}
+
+/// writeBlockDynamic encodes a block using a dynamic Huffman table.
+/// This should be used if the symbols used have a disproportionate
+/// histogram distribution.
+/// If input is supplied and the compression savings are below 1/16th of the
+/// input size the block is stored.
+fn dynamicBlock(
+    self: *BlockWriter,
+    tokens: []const Token,
+    eof: bool,
+    input: ?[]const u8,
+) Writer.Error!void {
+    const total_tokens = self.indexTokens(tokens);
+    const num_literals = total_tokens.num_literals;
+    const num_distances = total_tokens.num_distances;
+
+    // Generate codegen and codegenFrequencies, which indicates how to encode
+    // the literal_encoding and the distance_encoding.
+    self.generateCodegen(
+        num_literals,
+        num_distances,
+        &self.literal_encoding,
+        &self.distance_encoding,
+    );
+    self.codegen_encoding.generate(self.codegen_freq[0..], 7);
+    const dynamic_size = self.dynamicSize(&self.literal_encoding, &self.distance_encoding, 0);
+    const size = dynamic_size.size;
+    const num_codegens = dynamic_size.num_codegens;
+
+    // Store bytes, if we don't get a reasonable improvement.
+
+    const stored_size = storedSizeFits(input);
+    const ssize = stored_size.size;
+    const storable = stored_size.storable;
+    if (storable and ssize < (size + (size >> 4))) {
+        try self.storedBlock(input.?, eof);
+        return;
+    }
+
+    // Write Huffman table.
+    try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
+
+    // Write the tokens.
+    try self.writeTokens(tokens, &self.literal_encoding.codes, &self.distance_encoding.codes);
+}
+
+const TotalIndexedTokens = struct {
+    num_literals: u32,
+    num_distances: u32,
+};
+
+/// Indexes a slice of tokens followed by an end_block_marker, and updates
+/// literal_freq and distance_freq, and generates literal_encoding
+/// and distance_encoding.
+/// The number of literal and distance tokens is returned.
+fn indexTokens(self: *BlockWriter, tokens: []const Token) TotalIndexedTokens {
+    var num_literals: u32 = 0;
+    var num_distances: u32 = 0;
+
+    for (self.literal_freq, 0..) |_, i| {
+        self.literal_freq[i] = 0;
+    }
+    for (self.distance_freq, 0..) |_, i| {
+        self.distance_freq[i] = 0;
+    }
+
+    for (tokens) |t| {
+        if (t.kind == Token.Kind.literal) {
+            self.literal_freq[t.literal()] += 1;
+            continue;
+        }
+        self.literal_freq[t.lengthCode()] += 1;
+        self.distance_freq[t.distanceCode()] += 1;
+    }
+    // add end_block_marker token at the end
+    self.literal_freq[HuffmanEncoder.end_block_marker] += 1;
+
+    // get the number of literals
+    num_literals = @as(u32, @intCast(self.literal_freq.len));
+    while (self.literal_freq[num_literals - 1] == 0) {
+        num_literals -= 1;
+    }
+    // get the number of distances
+    num_distances = @as(u32, @intCast(self.distance_freq.len));
+    while (num_distances > 0 and self.distance_freq[num_distances - 1] == 0) {
+        num_distances -= 1;
+    }
+    if (num_distances == 0) {
+        // We haven't found a single match. If we want to go with the dynamic encoding,
+        // we should count at least one distance to be sure that the distance huffman tree could be encoded.
+        self.distance_freq[0] = 1;
+        num_distances = 1;
+    }
+    self.literal_encoding.generate(&self.literal_freq, 15);
+    self.distance_encoding.generate(&self.distance_freq, 15);
+    return TotalIndexedTokens{
+        .num_literals = num_literals,
+        .num_distances = num_distances,
+    };
+}
+
+/// Writes a slice of tokens to the output followed by and end_block_marker.
+/// codes for literal and distance encoding must be supplied.
+fn writeTokens(
+    self: *BlockWriter,
+    tokens: []const Token,
+    le_codes: []Compress.HuffCode,
+    oe_codes: []Compress.HuffCode,
+) Writer.Error!void {
+    for (tokens) |t| {
+        if (t.kind == Token.Kind.literal) {
+            try self.writeCode(le_codes[t.literal()]);
+            continue;
+        }
+
+        // Write the length
+        const le = t.lengthEncoding();
+        try self.writeCode(le_codes[le.code]);
+        if (le.extra_bits > 0) {
+            try self.bit_writer.writeBits(le.extra_length, le.extra_bits);
+        }
+
+        // Write the distance
+        const oe = t.distanceEncoding();
+        try self.writeCode(oe_codes[oe.code]);
+        if (oe.extra_bits > 0) {
+            try self.bit_writer.writeBits(oe.extra_distance, oe.extra_bits);
+        }
+    }
+    // add end_block_marker at the end
+    try self.writeCode(le_codes[HuffmanEncoder.end_block_marker]);
+}
+
+/// Encodes a block of bytes as either Huffman encoded literals or uncompressed bytes
+/// if the results only gains very little from compression.
+pub fn huffmanBlock(self: *BlockWriter, input: []const u8, eof: bool) Writer.Error!void {
+    // Add everything as literals
+    histogram(input, &self.literal_freq);
+
+    self.literal_freq[HuffmanEncoder.end_block_marker] = 1;
+
+    const num_literals = HuffmanEncoder.end_block_marker + 1;
+    self.distance_freq[0] = 1;
+    const num_distances = 1;
+
+    self.literal_encoding.generate(&self.literal_freq, 15);
+
+    // Figure out smallest code.
+    // Always use dynamic Huffman or Store
+    var num_codegens: u32 = 0;
+
+    // Generate codegen and codegenFrequencies, which indicates how to encode
+    // the literal_encoding and the distance_encoding.
+    self.generateCodegen(
+        num_literals,
+        num_distances,
+        &self.literal_encoding,
+        &self.huff_distance,
+    );
+    self.codegen_encoding.generate(self.codegen_freq[0..], 7);
+    const dynamic_size = self.dynamicSize(&self.literal_encoding, &self.huff_distance, 0);
+    const size = dynamic_size.size;
+    num_codegens = dynamic_size.num_codegens;
+
+    // Store bytes, if we don't get a reasonable improvement.
+    const stored_size_ret = storedSizeFits(input);
+    const ssize = stored_size_ret.size;
+    const storable = stored_size_ret.storable;
+
+    if (storable and ssize < (size + (size >> 4))) {
+        try self.storedBlock(input, eof);
+        return;
+    }
+
+    // Huffman.
+    try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
+    const encoding = self.literal_encoding.codes[0..257];
+
+    for (input) |t| {
+        const c = encoding[t];
+        try self.bit_writer.writeBits(c.code, c.len);
+    }
+    try self.writeCode(encoding[HuffmanEncoder.end_block_marker]);
+}
+
+fn histogram(b: []const u8, h: *[286]u16) void {
+    // Clear histogram
+    for (h, 0..) |_, i| {
+        h[i] = 0;
+    }
+
+    var lh = h.*[0..256];
+    for (b) |t| {
+        lh[t] += 1;
+    }
+}
diff --git a/lib/std/compress/flate/CircularBuffer.zig b/lib/std/compress/flate/CircularBuffer.zig
deleted file mode 100644
index 552d364894..0000000000
--- a/lib/std/compress/flate/CircularBuffer.zig
+++ /dev/null
@@ -1,240 +0,0 @@
-//! 64K buffer of uncompressed data created in inflate (decompression). Has enough
-//! history to support writing match<length, distance>; copying length of bytes
-//! from the position distance backward from current.
-//!
-//! Reads can return less than available bytes if they are spread across
-//! different circles. So reads should repeat until get required number of bytes
-//! or until returned slice is zero length.
-//!
-//! Note on deflate limits:
-//!  * non-compressible block is limited to 65,535 bytes.
-//!  * backward pointer is limited in distance to 32K bytes and in length to 258 bytes.
-//!
-//! Whole non-compressed block can be written without overlap. We always have
-//! history of up to 64K, more then 32K needed.
-//!
-const std = @import("std");
-const assert = std.debug.assert;
-const testing = std.testing;
-
-const consts = @import("consts.zig").match;
-
-const mask = 0xffff; // 64K - 1
-const buffer_len = mask + 1; // 64K buffer
-
-const Self = @This();
-
-buffer: [buffer_len]u8 = undefined,
-wp: usize = 0, // write position
-rp: usize = 0, // read position
-
-fn writeAll(self: *Self, buf: []const u8) void {
-    for (buf) |c| self.write(c);
-}
-
-/// Write literal.
-pub fn write(self: *Self, b: u8) void {
-    assert(self.wp - self.rp < mask);
-    self.buffer[self.wp & mask] = b;
-    self.wp += 1;
-}
-
-/// Write match (back-reference to the same data slice) starting at `distance`
-/// back from current write position, and `length` of bytes.
-pub fn writeMatch(self: *Self, length: u16, distance: u16) !void {
-    if (self.wp < distance or
-        length < consts.base_length or length > consts.max_length or
-        distance < consts.min_distance or distance > consts.max_distance)
-    {
-        return error.InvalidMatch;
-    }
-    assert(self.wp - self.rp < mask);
-
-    var from: usize = self.wp - distance & mask;
-    const from_end: usize = from + length;
-    var to: usize = self.wp & mask;
-    const to_end: usize = to + length;
-
-    self.wp += length;
-
-    // Fast path using memcpy
-    if (from_end < buffer_len and to_end < buffer_len) // start and end at the same circle
-    {
-        var cur_len = distance;
-        var remaining_len = length;
-        while (cur_len < remaining_len) {
-            @memcpy(self.buffer[to..][0..cur_len], self.buffer[from..][0..cur_len]);
-            to += cur_len;
-            remaining_len -= cur_len;
-            cur_len = cur_len * 2;
-        }
-        @memcpy(self.buffer[to..][0..remaining_len], self.buffer[from..][0..remaining_len]);
-        return;
-    }
-
-    // Slow byte by byte
-    while (to < to_end) {
-        self.buffer[to & mask] = self.buffer[from & mask];
-        to += 1;
-        from += 1;
-    }
-}
-
-/// Returns writable part of the internal buffer of size `n` at most. Advances
-/// write pointer, assumes that returned buffer will be filled with data.
-pub fn getWritable(self: *Self, n: usize) []u8 {
-    const wp = self.wp & mask;
-    const len = @min(n, buffer_len - wp);
-    self.wp += len;
-    return self.buffer[wp .. wp + len];
-}
-
-/// Read available data. Can return part of the available data if it is
-/// spread across two circles. So read until this returns zero length.
-pub fn read(self: *Self) []const u8 {
-    return self.readAtMost(buffer_len);
-}
-
-/// Read part of available data. Can return less than max even if there are
-/// more than max decoded data.
-pub fn readAtMost(self: *Self, limit: usize) []const u8 {
-    const rb = self.readBlock(if (limit == 0) buffer_len else limit);
-    defer self.rp += rb.len;
-    return self.buffer[rb.head..rb.tail];
-}
-
-const ReadBlock = struct {
-    head: usize,
-    tail: usize,
-    len: usize,
-};
-
-/// Returns position of continuous read block data.
-fn readBlock(self: *Self, max: usize) ReadBlock {
-    const r = self.rp & mask;
-    const w = self.wp & mask;
-    const n = @min(
-        max,
-        if (w >= r) w - r else buffer_len - r,
-    );
-    return .{
-        .head = r,
-        .tail = r + n,
-        .len = n,
-    };
-}
-
-/// Number of free bytes for write.
-pub fn free(self: *Self) usize {
-    return buffer_len - (self.wp - self.rp);
-}
-
-/// Full if largest match can't fit. 258 is largest match length. That much
-/// bytes can be produced in single decode step.
-pub fn full(self: *Self) bool {
-    return self.free() < 258 + 1;
-}
-
-// example from: https://youtu.be/SJPvNi4HrWQ?t=3558
-test writeMatch {
-    var cb: Self = .{};
-
-    cb.writeAll("a salad; ");
-    try cb.writeMatch(5, 9);
-    try cb.writeMatch(3, 3);
-
-    try testing.expectEqualStrings("a salad; a salsal", cb.read());
-}
-
-test "writeMatch overlap" {
-    var cb: Self = .{};
-
-    cb.writeAll("a b c ");
-    try cb.writeMatch(8, 4);
-    cb.write('d');
-
-    try testing.expectEqualStrings("a b c b c b c d", cb.read());
-}
-
-test readAtMost {
-    var cb: Self = .{};
-
-    cb.writeAll("0123456789");
-    try cb.writeMatch(50, 10);
-
-    try testing.expectEqualStrings("0123456789" ** 6, cb.buffer[cb.rp..cb.wp]);
-    for (0..6) |i| {
-        try testing.expectEqual(i * 10, cb.rp);
-        try testing.expectEqualStrings("0123456789", cb.readAtMost(10));
-    }
-    try testing.expectEqualStrings("", cb.readAtMost(10));
-    try testing.expectEqualStrings("", cb.read());
-}
-
-test Self {
-    var cb: Self = .{};
-
-    const data = "0123456789abcdef" ** (1024 / 16);
-    cb.writeAll(data);
-    try testing.expectEqual(@as(usize, 0), cb.rp);
-    try testing.expectEqual(@as(usize, 1024), cb.wp);
-    try testing.expectEqual(@as(usize, 1024 * 63), cb.free());
-
-    for (0..62 * 4) |_|
-        try cb.writeMatch(256, 1024); // write 62K
-
-    try testing.expectEqual(@as(usize, 0), cb.rp);
-    try testing.expectEqual(@as(usize, 63 * 1024), cb.wp);
-    try testing.expectEqual(@as(usize, 1024), cb.free());
-
-    cb.writeAll(data[0..200]);
-    _ = cb.readAtMost(1024); // make some space
-    cb.writeAll(data); // overflows write position
-    try testing.expectEqual(@as(usize, 200 + 65536), cb.wp);
-    try testing.expectEqual(@as(usize, 1024), cb.rp);
-    try testing.expectEqual(@as(usize, 1024 - 200), cb.free());
-
-    const rb = cb.readBlock(Self.buffer_len);
-    try testing.expectEqual(@as(usize, 65536 - 1024), rb.len);
-    try testing.expectEqual(@as(usize, 1024), rb.head);
-    try testing.expectEqual(@as(usize, 65536), rb.tail);
-
-    try testing.expectEqual(@as(usize, 65536 - 1024), cb.read().len); // read to the end of the buffer
-    try testing.expectEqual(@as(usize, 200 + 65536), cb.wp);
-    try testing.expectEqual(@as(usize, 65536), cb.rp);
-    try testing.expectEqual(@as(usize, 65536 - 200), cb.free());
-
-    try testing.expectEqual(@as(usize, 200), cb.read().len); // read the rest
-}
-
-test "write overlap" {
-    var cb: Self = .{};
-    cb.wp = cb.buffer.len - 15;
-    cb.rp = cb.wp;
-
-    cb.writeAll("0123456789");
-    cb.writeAll("abcdefghij");
-
-    try testing.expectEqual(cb.buffer.len + 5, cb.wp);
-    try testing.expectEqual(cb.buffer.len - 15, cb.rp);
-
-    try testing.expectEqualStrings("0123456789abcde", cb.read());
-    try testing.expectEqualStrings("fghij", cb.read());
-
-    try testing.expect(cb.wp == cb.rp);
-}
-
-test "writeMatch/read overlap" {
-    var cb: Self = .{};
-    cb.wp = cb.buffer.len - 15;
-    cb.rp = cb.wp;
-
-    cb.writeAll("0123456789");
-    try cb.writeMatch(15, 5);
-
-    try testing.expectEqualStrings("012345678956789", cb.read());
-    try testing.expectEqualStrings("5678956789", cb.read());
-
-    try cb.writeMatch(20, 25);
-    try testing.expectEqualStrings("01234567895678956789", cb.read());
-}
diff --git a/lib/std/compress/flate/Compress.zig b/lib/std/compress/flate/Compress.zig
new file mode 100644
index 0000000000..2249ece4c0
--- /dev/null
+++ b/lib/std/compress/flate/Compress.zig
@@ -0,0 +1,332 @@
+//! Default compression algorithm. Has two steps: tokenization and token
+//! encoding.
+//!
+//! Tokenization takes uncompressed input stream and produces list of tokens.
+//! Each token can be literal (byte of data) or match (backrefernce to previous
+//! data with length and distance). Tokenization accumulators 32K tokens, when
+//! full or `flush` is called tokens are passed to the `block_writer`. Level
+//! defines how hard (how slow) it tries to find match.
+//!
+//! Block writer will decide which type of deflate block to write (stored, fixed,
+//! dynamic) and encode tokens to the output byte stream. Client has to call
+//! `finish` to write block with the final bit set.
+//!
+//! Container defines type of header and footer which can be gzip, zlib or raw.
+//! They all share same deflate body. Raw has no header or footer just deflate
+//! body.
+//!
+//! Compression algorithm explained in rfc-1951 (slightly edited for this case):
+//!
+//!   The compressor uses a chained hash table `lookup` to find duplicated
+//!   strings, using a hash function that operates on 4-byte sequences. At any
+//!   given point during compression, let XYZW be the next 4 input bytes
+//!   (lookahead) to be examined (not necessarily all different, of course).
+//!   First, the compressor examines the hash chain for XYZW. If the chain is
+//!   empty, the compressor simply writes out X as a literal byte and advances
+//!   one byte in the input. If the hash chain is not empty, indicating that the
+//!   sequence XYZW (or, if we are unlucky, some other 4 bytes with the same
+//!   hash function value) has occurred recently, the compressor compares all
+//!   strings on the XYZW hash chain with the actual input data sequence
+//!   starting at the current point, and selects the longest match.
+//!
+//!   To improve overall compression, the compressor defers the selection of
+//!   matches ("lazy matching"): after a match of length N has been found, the
+//!   compressor searches for a longer match starting at the next input byte. If
+//!   it finds a longer match, it truncates the previous match to a length of
+//!   one (thus producing a single literal byte) and then emits the longer
+//!   match. Otherwise, it emits the original match, and, as described above,
+//!   advances N bytes before continuing.
+//!
+//!
+//! Allocates statically ~400K (192K lookup, 128K tokens, 64K window).
+
+const builtin = @import("builtin");
+const std = @import("std");
+const assert = std.debug.assert;
+const testing = std.testing;
+const expect = testing.expect;
+const mem = std.mem;
+const math = std.math;
+const Writer = std.Io.Writer;
+
+const Compress = @This();
+const Token = @import("Token.zig");
+const BlockWriter = @import("BlockWriter.zig");
+const flate = @import("../flate.zig");
+const Container = flate.Container;
+const Lookup = @import("Lookup.zig");
+const HuffmanEncoder = flate.HuffmanEncoder;
+const LiteralNode = HuffmanEncoder.LiteralNode;
+
+lookup: Lookup = .{},
+tokens: Tokens = .{},
+block_writer: BlockWriter,
+level: LevelArgs,
+hasher: Container.Hasher,
+writer: Writer,
+state: State,
+
+// Match and literal at the previous position.
+// Used for lazy match finding in processWindow.
+prev_match: ?Token = null,
+prev_literal: ?u8 = null,
+
+pub const State = enum { header, middle, ended };
+
+/// Trades between speed and compression size.
+/// Starts with level 4: in [zlib](https://github.com/madler/zlib/blob/abd3d1a28930f89375d4b41408b39f6c1be157b2/deflate.c#L115C1-L117C43)
+/// levels 1-3 are using different algorithm to perform faster but with less
+/// compression. That is not implemented here.
+pub const Level = enum(u4) {
+    level_4 = 4,
+    level_5 = 5,
+    level_6 = 6,
+    level_7 = 7,
+    level_8 = 8,
+    level_9 = 9,
+
+    fast = 0xb,
+    default = 0xc,
+    best = 0xd,
+};
+
+/// Number of tokens to accumulate in deflate before starting block encoding.
+///
+/// In zlib this depends on memlevel: 6 + memlevel, where default memlevel is
+/// 8 and max 9 that gives 14 or 15 bits.
+pub const n_tokens = 1 << 15;
+
+/// Algorithm knobs for each level.
+const LevelArgs = struct {
+    good: u16, // Do less lookups if we already have match of this length.
+    nice: u16, // Stop looking for better match if we found match with at least this length.
+    lazy: u16, // Don't do lazy match find if got match with at least this length.
+    chain: u16, // How many lookups for previous match to perform.
+
+    pub fn get(level: Level) LevelArgs {
+        return switch (level) {
+            .fast, .level_4 => .{ .good = 4, .lazy = 4, .nice = 16, .chain = 16 },
+            .level_5 => .{ .good = 8, .lazy = 16, .nice = 32, .chain = 32 },
+            .default, .level_6 => .{ .good = 8, .lazy = 16, .nice = 128, .chain = 128 },
+            .level_7 => .{ .good = 8, .lazy = 32, .nice = 128, .chain = 256 },
+            .level_8 => .{ .good = 32, .lazy = 128, .nice = 258, .chain = 1024 },
+            .best, .level_9 => .{ .good = 32, .lazy = 258, .nice = 258, .chain = 4096 },
+        };
+    }
+};
+
+pub const Options = struct {
+    level: Level = .default,
+    container: Container = .raw,
+};
+
+pub fn init(output: *Writer, buffer: []u8, options: Options) Compress {
+    return .{
+        .block_writer = .init(output),
+        .level = .get(options.level),
+        .hasher = .init(options.container),
+        .state = .header,
+        .writer = .{
+            .buffer = buffer,
+            .vtable = &.{ .drain = drain },
+        },
+    };
+}
+
+// Tokens store
+const Tokens = struct {
+    list: [n_tokens]Token = undefined,
+    pos: usize = 0,
+
+    fn add(self: *Tokens, t: Token) void {
+        self.list[self.pos] = t;
+        self.pos += 1;
+    }
+
+    fn full(self: *Tokens) bool {
+        return self.pos == self.list.len;
+    }
+
+    fn reset(self: *Tokens) void {
+        self.pos = 0;
+    }
+
+    fn tokens(self: *Tokens) []const Token {
+        return self.list[0..self.pos];
+    }
+};
+
+fn drain(me: *Writer, data: []const []const u8, splat: usize) Writer.Error!usize {
+    _ = data;
+    _ = splat;
+    const c: *Compress = @fieldParentPtr("writer", me);
+    const out = c.block_writer.output;
+    switch (c.state) {
+        .header => {
+            c.state = .middle;
+            const header = c.hasher.container().header();
+            try out.writeAll(header);
+            return header.len;
+        },
+        .middle => {},
+        .ended => unreachable,
+    }
+
+    const buffered = me.buffered();
+    const min_lookahead = Token.min_length + Token.max_length;
+    const history_plus_lookahead_len = flate.history_len + min_lookahead;
+    if (buffered.len < history_plus_lookahead_len) return 0;
+    const lookahead = buffered[flate.history_len..];
+
+    // TODO tokenize
+    _ = lookahead;
+    //c.hasher.update(lookahead[0..n]);
+    @panic("TODO");
+}
+
+pub fn end(c: *Compress) !void {
+    try endUnflushed(c);
+    const out = c.block_writer.output;
+    try out.flush();
+}
+
+pub fn endUnflushed(c: *Compress) !void {
+    while (c.writer.end != 0) _ = try drain(&c.writer, &.{""}, 1);
+    c.state = .ended;
+
+    const out = c.block_writer.output;
+
+    // TODO flush tokens
+
+    switch (c.hasher) {
+        .gzip => |*gzip| {
+            // GZIP 8 bytes footer
+            //  - 4 bytes, CRC32 (CRC-32)
+            //  - 4 bytes, ISIZE (Input SIZE) - size of the original (uncompressed) input data modulo 2^32
+            const footer = try out.writableArray(8);
+            std.mem.writeInt(u32, footer[0..4], gzip.crc.final(), .little);
+            std.mem.writeInt(u32, footer[4..8], @truncate(gzip.count), .little);
+        },
+        .zlib => |*zlib| {
+            // ZLIB (RFC 1950) is big-endian, unlike GZIP (RFC 1952).
+            // 4 bytes of ADLER32 (Adler-32 checksum)
+            // Checksum value of the uncompressed data (excluding any
+            // dictionary data) computed according to Adler-32
+            // algorithm.
+            std.mem.writeInt(u32, try out.writableArray(4), zlib.adler, .big);
+        },
+        .raw => {},
+    }
+}
+
+pub const Simple = struct {
+    /// Note that store blocks are limited to 65535 bytes.
+    buffer: []u8,
+    wp: usize,
+    block_writer: BlockWriter,
+    hasher: Container.Hasher,
+    strategy: Strategy,
+
+    pub const Strategy = enum { huffman, store };
+
+    pub fn init(output: *Writer, buffer: []u8, container: Container, strategy: Strategy) !Simple {
+        const header = container.header();
+        try output.writeAll(header);
+        return .{
+            .buffer = buffer,
+            .wp = 0,
+            .block_writer = .init(output),
+            .hasher = .init(container),
+            .strategy = strategy,
+        };
+    }
+
+    pub fn flush(self: *Simple) !void {
+        try self.flushBuffer(false);
+        try self.block_writer.storedBlock("", false);
+        try self.block_writer.flush();
+    }
+
+    pub fn finish(self: *Simple) !void {
+        try self.flushBuffer(true);
+        try self.block_writer.flush();
+        try self.hasher.container().writeFooter(&self.hasher, self.block_writer.output);
+    }
+
+    fn flushBuffer(self: *Simple, final: bool) !void {
+        const buf = self.buffer[0..self.wp];
+        switch (self.strategy) {
+            .huffman => try self.block_writer.huffmanBlock(buf, final),
+            .store => try self.block_writer.storedBlock(buf, final),
+        }
+        self.wp = 0;
+    }
+};
+
+test "generate a Huffman code from an array of frequencies" {
+    var freqs: [19]u16 = [_]u16{
+        8, // 0
+        1, // 1
+        1, // 2
+        2, // 3
+        5, // 4
+        10, // 5
+        9, // 6
+        1, // 7
+        0, // 8
+        0, // 9
+        0, // 10
+        0, // 11
+        0, // 12
+        0, // 13
+        0, // 14
+        0, // 15
+        1, // 16
+        3, // 17
+        5, // 18
+    };
+
+    var codes: [19]HuffmanEncoder.Code = undefined;
+    var enc: HuffmanEncoder = .{
+        .codes = &codes,
+        .freq_cache = undefined,
+        .bit_count = undefined,
+        .lns = undefined,
+        .lfs = undefined,
+    };
+    enc.generate(freqs[0..], 7);
+
+    try testing.expectEqual(@as(u32, 141), enc.bitLength(freqs[0..]));
+
+    try testing.expectEqual(@as(usize, 3), enc.codes[0].len);
+    try testing.expectEqual(@as(usize, 6), enc.codes[1].len);
+    try testing.expectEqual(@as(usize, 6), enc.codes[2].len);
+    try testing.expectEqual(@as(usize, 5), enc.codes[3].len);
+    try testing.expectEqual(@as(usize, 3), enc.codes[4].len);
+    try testing.expectEqual(@as(usize, 2), enc.codes[5].len);
+    try testing.expectEqual(@as(usize, 2), enc.codes[6].len);
+    try testing.expectEqual(@as(usize, 6), enc.codes[7].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[8].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[9].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[10].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[11].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[12].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[13].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[14].len);
+    try testing.expectEqual(@as(usize, 0), enc.codes[15].len);
+    try testing.expectEqual(@as(usize, 6), enc.codes[16].len);
+    try testing.expectEqual(@as(usize, 5), enc.codes[17].len);
+    try testing.expectEqual(@as(usize, 3), enc.codes[18].len);
+
+    try testing.expectEqual(@as(u16, 0x0), enc.codes[5].code);
+    try testing.expectEqual(@as(u16, 0x2), enc.codes[6].code);
+    try testing.expectEqual(@as(u16, 0x1), enc.codes[0].code);
+    try testing.expectEqual(@as(u16, 0x5), enc.codes[4].code);
+    try testing.expectEqual(@as(u16, 0x3), enc.codes[18].code);
+    try testing.expectEqual(@as(u16, 0x7), enc.codes[3].code);
+    try testing.expectEqual(@as(u16, 0x17), enc.codes[17].code);
+    try testing.expectEqual(@as(u16, 0x0f), enc.codes[1].code);
+    try testing.expectEqual(@as(u16, 0x2f), enc.codes[2].code);
+    try testing.expectEqual(@as(u16, 0x1f), enc.codes[7].code);
+    try testing.expectEqual(@as(u16, 0x3f), enc.codes[16].code);
+}
diff --git a/lib/std/compress/flate/Decompress.zig b/lib/std/compress/flate/Decompress.zig
new file mode 100644
index 0000000000..90f89ea6c9
--- /dev/null
+++ b/lib/std/compress/flate/Decompress.zig
@@ -0,0 +1,1270 @@
+const std = @import("../../std.zig");
+const assert = std.debug.assert;
+const flate = std.compress.flate;
+const testing = std.testing;
+const Writer = std.Io.Writer;
+const Reader = std.Io.Reader;
+const Container = flate.Container;
+
+const Decompress = @This();
+const Token = @import("Token.zig");
+
+input: *Reader,
+next_bits: Bits,
+remaining_bits: std.math.Log2Int(Bits),
+
+reader: Reader,
+
+container_metadata: Container.Metadata,
+
+lit_dec: LiteralDecoder,
+dst_dec: DistanceDecoder,
+
+final_block: bool,
+state: State,
+
+err: ?Error,
+
+/// TODO: change this to usize
+const Bits = u64;
+
+const BlockType = enum(u2) {
+    stored = 0,
+    fixed = 1,
+    dynamic = 2,
+};
+
+const State = union(enum) {
+    protocol_header,
+    block_header,
+    stored_block: u16,
+    fixed_block,
+    dynamic_block,
+    dynamic_block_literal: u8,
+    dynamic_block_match: u16,
+    protocol_footer,
+    end,
+};
+
+pub const Error = Container.Error || error{
+    InvalidCode,
+    InvalidMatch,
+    WrongStoredBlockNlen,
+    InvalidDynamicBlockHeader,
+    ReadFailed,
+    OversubscribedHuffmanTree,
+    IncompleteHuffmanTree,
+    MissingEndOfBlockCode,
+    EndOfStream,
+};
+
+const direct_vtable: Reader.VTable = .{
+    .stream = streamDirect,
+    .rebase = rebaseFallible,
+    .discard = discard,
+    .readVec = readVec,
+};
+
+const indirect_vtable: Reader.VTable = .{
+    .stream = streamIndirect,
+    .rebase = rebaseFallible,
+    .discard = discardIndirect,
+    .readVec = readVec,
+};
+
+pub fn init(input: *Reader, container: Container, buffer: []u8) Decompress {
+    return .{
+        .reader = .{
+            .vtable = if (buffer.len == 0) &direct_vtable else &indirect_vtable,
+            .buffer = buffer,
+            .seek = 0,
+            .end = 0,
+        },
+        .input = input,
+        .next_bits = 0,
+        .remaining_bits = 0,
+        .container_metadata = .init(container),
+        .lit_dec = .{},
+        .dst_dec = .{},
+        .final_block = false,
+        .state = .protocol_header,
+        .err = null,
+    };
+}
+
+fn rebaseFallible(r: *Reader, capacity: usize) Reader.RebaseError!void {
+    rebase(r, capacity);
+}
+
+fn rebase(r: *Reader, capacity: usize) void {
+    assert(capacity <= r.buffer.len - flate.history_len);
+    assert(r.end + capacity > r.buffer.len);
+    const discard_n = r.end - flate.history_len;
+    const keep = r.buffer[discard_n..r.end];
+    @memmove(r.buffer[0..keep.len], keep);
+    assert(keep.len != 0);
+    r.end = keep.len;
+    r.seek -= discard_n;
+}
+
+/// This could be improved so that when an amount is discarded that includes an
+/// entire frame, skip decoding that frame.
+fn discard(r: *Reader, limit: std.Io.Limit) Reader.Error!usize {
+    if (r.end + flate.history_len > r.buffer.len) rebase(r, flate.history_len);
+    var writer: Writer = .{
+        .vtable = &.{
+            .drain = std.Io.Writer.Discarding.drain,
+            .sendFile = std.Io.Writer.Discarding.sendFile,
+        },
+        .buffer = r.buffer,
+        .end = r.end,
+    };
+    defer {
+        assert(writer.end != 0);
+        r.end = writer.end;
+        r.seek = r.end;
+    }
+    const n = r.stream(&writer, limit) catch |err| switch (err) {
+        error.WriteFailed => unreachable,
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => return error.EndOfStream,
+    };
+    assert(n <= @intFromEnum(limit));
+    return n;
+}
+
+fn discardIndirect(r: *Reader, limit: std.Io.Limit) Reader.Error!usize {
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    if (r.end + flate.history_len > r.buffer.len) rebase(r, flate.history_len);
+    var writer: Writer = .{
+        .buffer = r.buffer,
+        .end = r.end,
+        .vtable = &.{ .drain = Writer.unreachableDrain },
+    };
+    {
+        defer r.end = writer.end;
+        _ = streamFallible(d, &writer, .limited(writer.buffer.len - writer.end)) catch |err| switch (err) {
+            error.WriteFailed => unreachable,
+            else => |e| return e,
+        };
+    }
+    const n = limit.minInt(r.end - r.seek);
+    r.seek += n;
+    return n;
+}
+
+fn readVec(r: *Reader, data: [][]u8) Reader.Error!usize {
+    _ = data;
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    return streamIndirectInner(d);
+}
+
+fn streamIndirectInner(d: *Decompress) Reader.Error!usize {
+    const r = &d.reader;
+    if (r.end + flate.history_len > r.buffer.len) rebase(r, flate.history_len);
+    var writer: Writer = .{
+        .buffer = r.buffer,
+        .end = r.end,
+        .vtable = &.{ .drain = Writer.unreachableDrain },
+    };
+    defer r.end = writer.end;
+    _ = streamFallible(d, &writer, .limited(writer.buffer.len - writer.end)) catch |err| switch (err) {
+        error.WriteFailed => unreachable,
+        else => |e| return e,
+    };
+    return 0;
+}
+
+fn decodeLength(self: *Decompress, code: u8) !u16 {
+    if (code > 28) return error.InvalidCode;
+    const ml = Token.matchLength(code);
+    return if (ml.extra_bits == 0) // 0 - 5 extra bits
+        ml.base
+    else
+        ml.base + try self.takeBitsRuntime(ml.extra_bits);
+}
+
+fn decodeDistance(self: *Decompress, code: u8) !u16 {
+    if (code > 29) return error.InvalidCode;
+    const md = Token.matchDistance(code);
+    return if (md.extra_bits == 0) // 0 - 13 extra bits
+        md.base
+    else
+        md.base + try self.takeBitsRuntime(md.extra_bits);
+}
+
+// Decode code length symbol to code length. Writes decoded length into
+// lens slice starting at position pos. Returns number of positions
+// advanced.
+fn dynamicCodeLength(self: *Decompress, code: u16, lens: []u4, pos: usize) !usize {
+    if (pos >= lens.len)
+        return error.InvalidDynamicBlockHeader;
+
+    switch (code) {
+        0...15 => {
+            // Represent code lengths of 0 - 15
+            lens[pos] = @intCast(code);
+            return 1;
+        },
+        16 => {
+            // Copy the previous code length 3 - 6 times.
+            // The next 2 bits indicate repeat length
+            const n: u8 = @as(u8, try self.takeBits(u2)) + 3;
+            if (pos == 0 or pos + n > lens.len)
+                return error.InvalidDynamicBlockHeader;
+            for (0..n) |i| {
+                lens[pos + i] = lens[pos + i - 1];
+            }
+            return n;
+        },
+        // Repeat a code length of 0 for 3 - 10 times. (3 bits of length)
+        17 => return @as(u8, try self.takeBits(u3)) + 3,
+        // Repeat a code length of 0 for 11 - 138 times (7 bits of length)
+        18 => return @as(u8, try self.takeBits(u7)) + 11,
+        else => return error.InvalidDynamicBlockHeader,
+    }
+}
+
+fn decodeSymbol(self: *Decompress, decoder: anytype) !Symbol {
+    // Maximum code len is 15 bits.
+    const sym = try decoder.find(@bitReverse(try self.peekBits(u15)));
+    try self.tossBits(sym.code_bits);
+    return sym;
+}
+
+fn streamDirect(r: *Reader, w: *Writer, limit: std.Io.Limit) Reader.StreamError!usize {
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    return streamFallible(d, w, limit);
+}
+
+fn streamIndirect(r: *Reader, w: *Writer, limit: std.Io.Limit) Reader.StreamError!usize {
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    _ = limit;
+    _ = w;
+    return streamIndirectInner(d);
+}
+
+fn streamFallible(d: *Decompress, w: *Writer, limit: std.Io.Limit) Reader.StreamError!usize {
+    return streamInner(d, w, limit) catch |err| switch (err) {
+        error.EndOfStream => {
+            if (d.state == .end) {
+                return error.EndOfStream;
+            } else {
+                d.err = error.EndOfStream;
+                return error.ReadFailed;
+            }
+        },
+        error.WriteFailed => return error.WriteFailed,
+        else => |e| {
+            // In the event of an error, state is unmodified so that it can be
+            // better used to diagnose the failure.
+            d.err = e;
+            return error.ReadFailed;
+        },
+    };
+}
+
+fn streamInner(d: *Decompress, w: *Writer, limit: std.Io.Limit) (Error || Reader.StreamError)!usize {
+    var remaining = @intFromEnum(limit);
+    const in = d.input;
+    sw: switch (d.state) {
+        .protocol_header => switch (d.container_metadata.container()) {
+            .gzip => {
+                const Header = extern struct {
+                    magic: u16 align(1),
+                    method: u8,
+                    flags: packed struct(u8) {
+                        text: bool,
+                        hcrc: bool,
+                        extra: bool,
+                        name: bool,
+                        comment: bool,
+                        reserved: u3,
+                    },
+                    mtime: u32 align(1),
+                    xfl: u8,
+                    os: u8,
+                };
+                const header = try in.takeStruct(Header, .little);
+                if (header.magic != 0x8b1f or header.method != 0x08)
+                    return error.BadGzipHeader;
+                if (header.flags.extra) {
+                    const extra_len = try in.takeInt(u16, .little);
+                    try in.discardAll(extra_len);
+                }
+                if (header.flags.name) {
+                    _ = try in.discardDelimiterInclusive(0);
+                }
+                if (header.flags.comment) {
+                    _ = try in.discardDelimiterInclusive(0);
+                }
+                if (header.flags.hcrc) {
+                    try in.discardAll(2);
+                }
+                continue :sw .block_header;
+            },
+            .zlib => {
+                const header = try in.takeArray(2);
+                const cmf: packed struct(u8) { cm: u4, cinfo: u4 } = @bitCast(header[0]);
+                if (cmf.cm != 8 or cmf.cinfo > 7) return error.BadZlibHeader;
+                continue :sw .block_header;
+            },
+            .raw => continue :sw .block_header,
+        },
+        .block_header => {
+            d.final_block = (try d.takeBits(u1)) != 0;
+            const block_type: BlockType = @enumFromInt(try d.takeBits(u2));
+            switch (block_type) {
+                .stored => {
+                    d.alignBitsDiscarding();
+                    // everything after this is byte aligned in stored block
+                    const len = try in.takeInt(u16, .little);
+                    const nlen = try in.takeInt(u16, .little);
+                    if (len != ~nlen) return error.WrongStoredBlockNlen;
+                    continue :sw .{ .stored_block = len };
+                },
+                .fixed => continue :sw .fixed_block,
+                .dynamic => {
+                    const hlit: u16 = @as(u16, try d.takeBits(u5)) + 257; // number of ll code entries present - 257
+                    const hdist: u16 = @as(u16, try d.takeBits(u5)) + 1; // number of distance code entries - 1
+                    const hclen: u8 = @as(u8, try d.takeBits(u4)) + 4; // hclen + 4 code lengths are encoded
+
+                    if (hlit > 286 or hdist > 30)
+                        return error.InvalidDynamicBlockHeader;
+
+                    // lengths for code lengths
+                    var cl_lens: [19]u4 = @splat(0);
+                    for (flate.HuffmanEncoder.codegen_order[0..hclen]) |i| {
+                        cl_lens[i] = try d.takeBits(u3);
+                    }
+                    var cl_dec: CodegenDecoder = .{};
+                    try cl_dec.generate(&cl_lens);
+
+                    // decoded code lengths
+                    var dec_lens: [286 + 30]u4 = @splat(0);
+                    var pos: usize = 0;
+                    while (pos < hlit + hdist) {
+                        const peeked = @bitReverse(try d.peekBits(u7));
+                        const sym = try cl_dec.find(peeked);
+                        try d.tossBits(sym.code_bits);
+                        pos += try d.dynamicCodeLength(sym.symbol, &dec_lens, pos);
+                    }
+                    if (pos > hlit + hdist) {
+                        return error.InvalidDynamicBlockHeader;
+                    }
+
+                    // literal code lengths to literal decoder
+                    try d.lit_dec.generate(dec_lens[0..hlit]);
+
+                    // distance code lengths to distance decoder
+                    try d.dst_dec.generate(dec_lens[hlit..][0..hdist]);
+
+                    continue :sw .dynamic_block;
+                },
+            }
+        },
+        .stored_block => |remaining_len| {
+            const out = try w.writableSliceGreedyPreserve(flate.history_len, 1);
+            var limited_out: [1][]u8 = .{limit.min(.limited(remaining_len)).slice(out)};
+            const n = try d.input.readVec(&limited_out);
+            if (remaining_len - n == 0) {
+                d.state = if (d.final_block) .protocol_footer else .block_header;
+            } else {
+                d.state = .{ .stored_block = @intCast(remaining_len - n) };
+            }
+            w.advance(n);
+            return n;
+        },
+        .fixed_block => {
+            while (remaining > 0) {
+                const code = try d.readFixedCode();
+                switch (code) {
+                    0...255 => {
+                        try w.writeBytePreserve(flate.history_len, @intCast(code));
+                        remaining -= 1;
+                    },
+                    256 => {
+                        d.state = if (d.final_block) .protocol_footer else .block_header;
+                        return @intFromEnum(limit) - remaining;
+                    },
+                    257...285 => {
+                        // Handles fixed block non literal (length) code.
+                        // Length code is followed by 5 bits of distance code.
+                        const length = try d.decodeLength(@intCast(code - 257));
+                        const distance = try d.decodeDistance(@bitReverse(try d.takeBits(u5)));
+                        try writeMatch(w, length, distance);
+                        remaining -= length;
+                    },
+                    else => return error.InvalidCode,
+                }
+            }
+            d.state = .fixed_block;
+            return @intFromEnum(limit) - remaining;
+        },
+        .dynamic_block => {
+            // In larger archives most blocks are usually dynamic, so
+            // decompression performance depends on this logic.
+            var sym = try d.decodeSymbol(&d.lit_dec);
+            sym: switch (sym.kind) {
+                .literal => {
+                    if (remaining != 0) {
+                        @branchHint(.likely);
+                        remaining -= 1;
+                        try w.writeBytePreserve(flate.history_len, sym.symbol);
+                        sym = try d.decodeSymbol(&d.lit_dec);
+                        continue :sym sym.kind;
+                    } else {
+                        d.state = .{ .dynamic_block_literal = sym.symbol };
+                        return @intFromEnum(limit) - remaining;
+                    }
+                },
+                .match => {
+                    // Decode match backreference <length, distance>
+                    const length = try d.decodeLength(sym.symbol);
+                    continue :sw .{ .dynamic_block_match = length };
+                },
+                .end_of_block => {
+                    d.state = if (d.final_block) .protocol_footer else .block_header;
+                    continue :sw d.state;
+                },
+            }
+        },
+        .dynamic_block_literal => |symbol| {
+            assert(remaining != 0);
+            remaining -= 1;
+            try w.writeBytePreserve(flate.history_len, symbol);
+            continue :sw .dynamic_block;
+        },
+        .dynamic_block_match => |length| {
+            if (remaining >= length) {
+                @branchHint(.likely);
+                remaining -= length;
+                const dsm = try d.decodeSymbol(&d.dst_dec);
+                const distance = try d.decodeDistance(dsm.symbol);
+                try writeMatch(w, length, distance);
+                continue :sw .dynamic_block;
+            } else {
+                d.state = .{ .dynamic_block_match = length };
+                return @intFromEnum(limit) - remaining;
+            }
+        },
+        .protocol_footer => {
+            switch (d.container_metadata) {
+                .gzip => |*gzip| {
+                    d.alignBitsDiscarding();
+                    gzip.* = .{
+                        .crc = try in.takeInt(u32, .little),
+                        .count = try in.takeInt(u32, .little),
+                    };
+                },
+                .zlib => |*zlib| {
+                    d.alignBitsDiscarding();
+                    zlib.* = .{
+                        .adler = try in.takeInt(u32, .little),
+                    };
+                },
+                .raw => {
+                    d.alignBitsPreserving();
+                },
+            }
+            d.state = .end;
+            return @intFromEnum(limit) - remaining;
+        },
+        .end => return error.EndOfStream,
+    }
+}
+
+/// Write match (back-reference to the same data slice) starting at `distance`
+/// back from current write position, and `length` of bytes.
+fn writeMatch(w: *Writer, length: u16, distance: u16) !void {
+    if (w.end < distance) return error.InvalidMatch;
+    if (length < Token.base_length) return error.InvalidMatch;
+    if (length > Token.max_length) return error.InvalidMatch;
+    if (distance < Token.min_distance) return error.InvalidMatch;
+    if (distance > Token.max_distance) return error.InvalidMatch;
+
+    // This is not a @memmove; it intentionally repeats patterns caused by
+    // iterating one byte at a time.
+    const dest = try w.writableSlicePreserve(flate.history_len, length);
+    const end = dest.ptr - w.buffer.ptr;
+    const src = w.buffer[end - distance ..][0..length];
+    for (dest, src) |*d, s| d.* = s;
+}
+
+fn takeBits(d: *Decompress, comptime U: type) !U {
+    const remaining_bits = d.remaining_bits;
+    const next_bits = d.next_bits;
+    if (remaining_bits >= @bitSizeOf(U)) {
+        const u: U = @truncate(next_bits);
+        d.next_bits = next_bits >> @bitSizeOf(U);
+        d.remaining_bits = remaining_bits - @bitSizeOf(U);
+        return u;
+    }
+    const in = d.input;
+    const next_int = in.takeInt(Bits, .little) catch |err| switch (err) {
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => return takeBitsEnding(d, U),
+    };
+    const needed_bits = @bitSizeOf(U) - remaining_bits;
+    const u: U = @intCast(((next_int & ((@as(Bits, 1) << needed_bits) - 1)) << remaining_bits) | next_bits);
+    d.next_bits = next_int >> needed_bits;
+    d.remaining_bits = @intCast(@bitSizeOf(Bits) - @as(usize, needed_bits));
+    return u;
+}
+
+fn takeBitsEnding(d: *Decompress, comptime U: type) !U {
+    const remaining_bits = d.remaining_bits;
+    const next_bits = d.next_bits;
+    const in = d.input;
+    const n = in.bufferedLen();
+    assert(n < @sizeOf(Bits));
+    const needed_bits = @bitSizeOf(U) - remaining_bits;
+    if (n * 8 < needed_bits) return error.EndOfStream;
+    const next_int = in.takeVarInt(Bits, .little, n) catch |err| switch (err) {
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => unreachable,
+    };
+    const u: U = @intCast(((next_int & ((@as(Bits, 1) << needed_bits) - 1)) << remaining_bits) | next_bits);
+    d.next_bits = next_int >> needed_bits;
+    d.remaining_bits = @intCast(n * 8 - @as(usize, needed_bits));
+    return u;
+}
+
+fn peekBits(d: *Decompress, comptime U: type) !U {
+    const remaining_bits = d.remaining_bits;
+    const next_bits = d.next_bits;
+    if (remaining_bits >= @bitSizeOf(U)) return @truncate(next_bits);
+    const in = d.input;
+    const next_int = in.peekInt(Bits, .little) catch |err| switch (err) {
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => return peekBitsEnding(d, U),
+    };
+    const needed_bits = @bitSizeOf(U) - remaining_bits;
+    return @intCast(((next_int & ((@as(Bits, 1) << needed_bits) - 1)) << remaining_bits) | next_bits);
+}
+
+fn peekBitsEnding(d: *Decompress, comptime U: type) !U {
+    const remaining_bits = d.remaining_bits;
+    const next_bits = d.next_bits;
+    const in = d.input;
+    var u: Bits = 0;
+    var remaining_needed_bits = @bitSizeOf(U) - remaining_bits;
+    var i: usize = 0;
+    while (remaining_needed_bits >= 8) {
+        const byte = try specialPeek(in, next_bits, i);
+        u |= @as(Bits, byte) << @intCast(i * 8);
+        remaining_needed_bits -= 8;
+        i += 1;
+    }
+    if (remaining_needed_bits != 0) {
+        const byte = try specialPeek(in, next_bits, i);
+        u |= @as(Bits, byte) << @intCast((i * 8) + remaining_needed_bits);
+    }
+    return @truncate((u << remaining_bits) | next_bits);
+}
+
+/// If there is any unconsumed data, handles EndOfStream by pretending there
+/// are zeroes afterwards.
+fn specialPeek(in: *Reader, next_bits: Bits, i: usize) Reader.Error!u8 {
+    const peeked = in.peek(i + 1) catch |err| switch (err) {
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => if (next_bits == 0 and i == 0) return error.EndOfStream else return 0,
+    };
+    return peeked[i];
+}
+
+fn tossBits(d: *Decompress, n: u4) !void {
+    const remaining_bits = d.remaining_bits;
+    const next_bits = d.next_bits;
+    if (remaining_bits >= n) {
+        d.next_bits = next_bits >> n;
+        d.remaining_bits = remaining_bits - n;
+    } else {
+        const in = d.input;
+        const next_int = in.takeInt(Bits, .little) catch |err| switch (err) {
+            error.ReadFailed => return error.ReadFailed,
+            error.EndOfStream => return tossBitsEnding(d, n),
+        };
+        const needed_bits = n - remaining_bits;
+        d.next_bits = next_int >> needed_bits;
+        d.remaining_bits = @intCast(@bitSizeOf(Bits) - @as(usize, needed_bits));
+    }
+}
+
+fn tossBitsEnding(d: *Decompress, n: u4) !void {
+    const remaining_bits = d.remaining_bits;
+    const in = d.input;
+    const buffered_n = in.bufferedLen();
+    if (buffered_n == 0) return error.EndOfStream;
+    assert(buffered_n < @sizeOf(Bits));
+    const needed_bits = n - remaining_bits;
+    const next_int = in.takeVarInt(Bits, .little, buffered_n) catch |err| switch (err) {
+        error.ReadFailed => return error.ReadFailed,
+        error.EndOfStream => unreachable,
+    };
+    d.next_bits = next_int >> needed_bits;
+    d.remaining_bits = @intCast(@as(usize, n) * 8 -| @as(usize, needed_bits));
+}
+
+fn takeBitsRuntime(d: *Decompress, n: u4) !u16 {
+    const x = try peekBits(d, u16);
+    const mask: u16 = (@as(u16, 1) << n) - 1;
+    const u: u16 = @as(u16, @truncate(x)) & mask;
+    try tossBits(d, n);
+    return u;
+}
+
+fn alignBitsDiscarding(d: *Decompress) void {
+    const remaining_bits = d.remaining_bits;
+    if (remaining_bits == 0) return;
+    const n_bytes = remaining_bits / 8;
+    const in = d.input;
+    in.seek -= n_bytes;
+    d.remaining_bits = 0;
+    d.next_bits = 0;
+}
+
+fn alignBitsPreserving(d: *Decompress) void {
+    const remaining_bits: usize = d.remaining_bits;
+    if (remaining_bits == 0) return;
+    const n_bytes = (remaining_bits + 7) / 8;
+    const in = d.input;
+    in.seek -= n_bytes;
+    d.remaining_bits = 0;
+    d.next_bits = 0;
+}
+
+/// Reads first 7 bits, and then maybe 1 or 2 more to get full 7,8 or 9 bit code.
+/// ref: https://datatracker.ietf.org/doc/html/rfc1951#page-12
+///         Lit Value    Bits        Codes
+///          ---------    ----        -----
+///            0 - 143     8          00110000 through
+///                                   10111111
+///          144 - 255     9          110010000 through
+///                                   111111111
+///          256 - 279     7          0000000 through
+///                                   0010111
+///          280 - 287     8          11000000 through
+///                                   11000111
+fn readFixedCode(d: *Decompress) !u16 {
+    const code7 = @bitReverse(try d.takeBits(u7));
+    return switch (code7) {
+        0...0b0010_111 => @as(u16, code7) + 256,
+        0b0010_111 + 1...0b1011_111 => (@as(u16, code7) << 1) + @as(u16, try d.takeBits(u1)) - 0b0011_0000,
+        0b1011_111 + 1...0b1100_011 => (@as(u16, code7 - 0b1100000) << 1) + try d.takeBits(u1) + 280,
+        else => (@as(u16, code7 - 0b1100_100) << 2) + @as(u16, @bitReverse(try d.takeBits(u2))) + 144,
+    };
+}
+
+pub const Symbol = packed struct {
+    pub const Kind = enum(u2) {
+        literal,
+        end_of_block,
+        match,
+    };
+
+    symbol: u8 = 0, // symbol from alphabet
+    code_bits: u4 = 0, // number of bits in code 0-15
+    kind: Kind = .literal,
+
+    code: u16 = 0, // huffman code of the symbol
+    next: u16 = 0, // pointer to the next symbol in linked list
+    // it is safe to use 0 as null pointer, when sorted 0 has shortest code and fits into lookup
+
+    // Sorting less than function.
+    pub fn asc(_: void, a: Symbol, b: Symbol) bool {
+        if (a.code_bits == b.code_bits) {
+            if (a.kind == b.kind) {
+                return a.symbol < b.symbol;
+            }
+            return @intFromEnum(a.kind) < @intFromEnum(b.kind);
+        }
+        return a.code_bits < b.code_bits;
+    }
+};
+
+pub const LiteralDecoder = HuffmanDecoder(286, 15, 9);
+pub const DistanceDecoder = HuffmanDecoder(30, 15, 9);
+pub const CodegenDecoder = HuffmanDecoder(19, 7, 7);
+
+/// Creates huffman tree codes from list of code lengths (in `build`).
+///
+/// `find` then finds symbol for code bits. Code can be any length between 1 and
+/// 15 bits. When calling `find` we don't know how many bits will be used to
+/// find symbol. When symbol is returned it has code_bits field which defines
+/// how much we should advance in bit stream.
+///
+/// Lookup table is used to map 15 bit int to symbol. Same symbol is written
+/// many times in this table; 32K places for 286 (at most) symbols.
+/// Small lookup table is optimization for faster search.
+/// It is variation of the algorithm explained in [zlib](https://github.com/madler/zlib/blob/643e17b7498d12ab8d15565662880579692f769d/doc/algorithm.txt#L92)
+/// with difference that we here use statically allocated arrays.
+///
+fn HuffmanDecoder(
+    comptime alphabet_size: u16,
+    comptime max_code_bits: u4,
+    comptime lookup_bits: u4,
+) type {
+    const lookup_shift = max_code_bits - lookup_bits;
+
+    return struct {
+        // all symbols in alaphabet, sorted by code_len, symbol
+        symbols: [alphabet_size]Symbol = undefined,
+        // lookup table code -> symbol
+        lookup: [1 << lookup_bits]Symbol = undefined,
+
+        const Self = @This();
+
+        /// Generates symbols and lookup tables from list of code lens for each symbol.
+        pub fn generate(self: *Self, lens: []const u4) !void {
+            try checkCompleteness(lens);
+
+            // init alphabet with code_bits
+            for (self.symbols, 0..) |_, i| {
+                const cb: u4 = if (i < lens.len) lens[i] else 0;
+                self.symbols[i] = if (i < 256)
+                    .{ .kind = .literal, .symbol = @intCast(i), .code_bits = cb }
+                else if (i == 256)
+                    .{ .kind = .end_of_block, .symbol = 0xff, .code_bits = cb }
+                else
+                    .{ .kind = .match, .symbol = @intCast(i - 257), .code_bits = cb };
+            }
+            std.sort.heap(Symbol, &self.symbols, {}, Symbol.asc);
+
+            // reset lookup table
+            for (0..self.lookup.len) |i| {
+                self.lookup[i] = .{};
+            }
+
+            // assign code to symbols
+            // reference: https://youtu.be/9_YEGLe33NA?list=PLU4IQLU9e_OrY8oASHx0u3IXAL9TOdidm&t=2639
+            var code: u16 = 0;
+            var idx: u16 = 0;
+            for (&self.symbols, 0..) |*sym, pos| {
+                if (sym.code_bits == 0) continue; // skip unused
+                sym.code = code;
+
+                const next_code = code + (@as(u16, 1) << (max_code_bits - sym.code_bits));
+                const next_idx = next_code >> lookup_shift;
+
+                if (next_idx > self.lookup.len or idx >= self.lookup.len) break;
+                if (sym.code_bits <= lookup_bits) {
+                    // fill small lookup table
+                    for (idx..next_idx) |j|
+                        self.lookup[j] = sym.*;
+                } else {
+                    // insert into linked table starting at root
+                    const root = &self.lookup[idx];
+                    const root_next = root.next;
+                    root.next = @intCast(pos);
+                    sym.next = root_next;
+                }
+
+                idx = next_idx;
+                code = next_code;
+            }
+        }
+
+        /// Given the list of code lengths check that it represents a canonical
+        /// Huffman code for n symbols.
+        ///
+        /// Reference: https://github.com/madler/zlib/blob/5c42a230b7b468dff011f444161c0145b5efae59/contrib/puff/puff.c#L340
+        fn checkCompleteness(lens: []const u4) !void {
+            if (alphabet_size == 286)
+                if (lens[256] == 0) return error.MissingEndOfBlockCode;
+
+            var count = [_]u16{0} ** (@as(usize, max_code_bits) + 1);
+            var max: usize = 0;
+            for (lens) |n| {
+                if (n == 0) continue;
+                if (n > max) max = n;
+                count[n] += 1;
+            }
+            if (max == 0) // empty tree
+                return;
+
+            // check for an over-subscribed or incomplete set of lengths
+            var left: usize = 1; // one possible code of zero length
+            for (1..count.len) |len| {
+                left <<= 1; // one more bit, double codes left
+                if (count[len] > left)
+                    return error.OversubscribedHuffmanTree;
+                left -= count[len]; // deduct count from possible codes
+            }
+            if (left > 0) { // left > 0 means incomplete
+                // incomplete code ok only for single length 1 code
+                if (max_code_bits > 7 and max == count[0] + count[1]) return;
+                return error.IncompleteHuffmanTree;
+            }
+        }
+
+        /// Finds symbol for lookup table code.
+        pub fn find(self: *Self, code: u16) !Symbol {
+            // try to find in lookup table
+            const idx = code >> lookup_shift;
+            const sym = self.lookup[idx];
+            if (sym.code_bits != 0) return sym;
+            // if not use linked list of symbols with same prefix
+            return self.findLinked(code, sym.next);
+        }
+
+        inline fn findLinked(self: *Self, code: u16, start: u16) !Symbol {
+            var pos = start;
+            while (pos > 0) {
+                const sym = self.symbols[pos];
+                const shift = max_code_bits - sym.code_bits;
+                // compare code_bits number of upper bits
+                if ((code ^ sym.code) >> shift == 0) return sym;
+                pos = sym.next;
+            }
+            return error.InvalidCode;
+        }
+    };
+}
+
+test "init/find" {
+    // example data from: https://youtu.be/SJPvNi4HrWQ?t=8423
+    const code_lens = [_]u4{ 4, 3, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 3, 2 };
+    var h: CodegenDecoder = .{};
+    try h.generate(&code_lens);
+
+    const expected = [_]struct {
+        sym: Symbol,
+        code: u16,
+    }{
+        .{
+            .code = 0b00_00000,
+            .sym = .{ .symbol = 3, .code_bits = 2 },
+        },
+        .{
+            .code = 0b01_00000,
+            .sym = .{ .symbol = 18, .code_bits = 2 },
+        },
+        .{
+            .code = 0b100_0000,
+            .sym = .{ .symbol = 1, .code_bits = 3 },
+        },
+        .{
+            .code = 0b101_0000,
+            .sym = .{ .symbol = 4, .code_bits = 3 },
+        },
+        .{
+            .code = 0b110_0000,
+            .sym = .{ .symbol = 17, .code_bits = 3 },
+        },
+        .{
+            .code = 0b1110_000,
+            .sym = .{ .symbol = 0, .code_bits = 4 },
+        },
+        .{
+            .code = 0b1111_000,
+            .sym = .{ .symbol = 16, .code_bits = 4 },
+        },
+    };
+
+    // unused symbols
+    for (0..12) |i| {
+        try testing.expectEqual(0, h.symbols[i].code_bits);
+    }
+    // used, from index 12
+    for (expected, 12..) |e, i| {
+        try testing.expectEqual(e.sym.symbol, h.symbols[i].symbol);
+        try testing.expectEqual(e.sym.code_bits, h.symbols[i].code_bits);
+        const sym_from_code = try h.find(e.code);
+        try testing.expectEqual(e.sym.symbol, sym_from_code.symbol);
+    }
+
+    // All possible codes for each symbol.
+    // Lookup table has 126 elements, to cover all possible 7 bit codes.
+    for (0b0000_000..0b0100_000) |c| // 0..32 (32)
+        try testing.expectEqual(3, (try h.find(@intCast(c))).symbol);
+
+    for (0b0100_000..0b1000_000) |c| // 32..64 (32)
+        try testing.expectEqual(18, (try h.find(@intCast(c))).symbol);
+
+    for (0b1000_000..0b1010_000) |c| // 64..80 (16)
+        try testing.expectEqual(1, (try h.find(@intCast(c))).symbol);
+
+    for (0b1010_000..0b1100_000) |c| // 80..96 (16)
+        try testing.expectEqual(4, (try h.find(@intCast(c))).symbol);
+
+    for (0b1100_000..0b1110_000) |c| // 96..112 (16)
+        try testing.expectEqual(17, (try h.find(@intCast(c))).symbol);
+
+    for (0b1110_000..0b1111_000) |c| // 112..120 (8)
+        try testing.expectEqual(0, (try h.find(@intCast(c))).symbol);
+
+    for (0b1111_000..0b1_0000_000) |c| // 120...128 (8)
+        try testing.expectEqual(16, (try h.find(@intCast(c))).symbol);
+}
+
+test "encode/decode literals" {
+    var codes: [flate.HuffmanEncoder.max_num_frequencies]flate.HuffmanEncoder.Code = undefined;
+    for (1..286) |j| { // for all different number of codes
+        var enc: flate.HuffmanEncoder = .{
+            .codes = &codes,
+            .freq_cache = undefined,
+            .bit_count = undefined,
+            .lns = undefined,
+            .lfs = undefined,
+        };
+        // create frequencies
+        var freq = [_]u16{0} ** 286;
+        freq[256] = 1; // ensure we have end of block code
+        for (&freq, 1..) |*f, i| {
+            if (i % j == 0)
+                f.* = @intCast(i);
+        }
+
+        // encoder from frequencies
+        enc.generate(&freq, 15);
+
+        // get code_lens from encoder
+        var code_lens = [_]u4{0} ** 286;
+        for (code_lens, 0..) |_, i| {
+            code_lens[i] = @intCast(enc.codes[i].len);
+        }
+        // generate decoder from code lens
+        var dec: LiteralDecoder = .{};
+        try dec.generate(&code_lens);
+
+        // expect decoder code to match original encoder code
+        for (dec.symbols) |s| {
+            if (s.code_bits == 0) continue;
+            const c_code: u16 = @bitReverse(@as(u15, @intCast(s.code)));
+            const symbol: u16 = switch (s.kind) {
+                .literal => s.symbol,
+                .end_of_block => 256,
+                .match => @as(u16, s.symbol) + 257,
+            };
+
+            const c = enc.codes[symbol];
+            try testing.expect(c.code == c_code);
+        }
+
+        // find each symbol by code
+        for (enc.codes) |c| {
+            if (c.len == 0) continue;
+
+            const s_code: u15 = @bitReverse(@as(u15, @intCast(c.code)));
+            const s = try dec.find(s_code);
+            try testing.expect(s.code == s_code);
+            try testing.expect(s.code_bits == c.len);
+        }
+    }
+}
+
+test "non compressed block (type 0)" {
+    try testDecompress(.raw, &[_]u8{
+        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
+        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
+    }, "Hello world\n");
+}
+
+test "fixed code block (type 1)" {
+    try testDecompress(.raw, &[_]u8{
+        0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, // deflate data block type 1
+        0x2f, 0xca, 0x49, 0xe1, 0x02, 0x00,
+    }, "Hello world\n");
+}
+
+test "dynamic block (type 2)" {
+    try testDecompress(.raw, &[_]u8{
+        0x3d, 0xc6, 0x39, 0x11, 0x00, 0x00, 0x0c, 0x02, // deflate data block type 2
+        0x30, 0x2b, 0xb5, 0x52, 0x1e, 0xff, 0x96, 0x38,
+        0x16, 0x96, 0x5c, 0x1e, 0x94, 0xcb, 0x6d, 0x01,
+    }, "ABCDEABCD ABCDEABCD");
+}
+
+test "gzip non compressed block (type 0)" {
+    try testDecompress(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, // gzip header (10 bytes)
+        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
+        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
+        0xd5, 0xe0, 0x39, 0xb7, // gzip footer: checksum
+        0x0c, 0x00, 0x00, 0x00, // gzip footer: size
+    }, "Hello world\n");
+}
+
+test "gzip fixed code block (type 1)" {
+    try testDecompress(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x03, // gzip header (10 bytes)
+        0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, // deflate data block type 1
+        0x2f, 0xca, 0x49, 0xe1, 0x02, 0x00,
+        0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00, // gzip footer (chksum, len)
+    }, "Hello world\n");
+}
+
+test "gzip dynamic block (type 2)" {
+    try testDecompress(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, // gzip header (10 bytes)
+        0x3d, 0xc6, 0x39, 0x11, 0x00, 0x00, 0x0c, 0x02, // deflate data block type 2
+        0x30, 0x2b, 0xb5, 0x52, 0x1e, 0xff, 0x96, 0x38,
+        0x16, 0x96, 0x5c, 0x1e, 0x94, 0xcb, 0x6d, 0x01,
+        0x17, 0x1c, 0x39, 0xb4, 0x13, 0x00, 0x00, 0x00, // gzip footer (chksum, len)
+    }, "ABCDEABCD ABCDEABCD");
+}
+
+test "gzip header with name" {
+    try testDecompress(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x08, 0xe5, 0x70, 0xb1, 0x65, 0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
+        0x74, 0x78, 0x74, 0x00, 0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
+        0x02, 0x00, 0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00,
+    }, "Hello world\n");
+}
+
+test "zlib decompress non compressed block (type 0)" {
+    try testDecompress(.zlib, &[_]u8{
+        0x78, 0b10_0_11100, // zlib header (2 bytes)
+        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
+        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
+        0x1c, 0xf2, 0x04, 0x47, // zlib footer: checksum
+    }, "Hello world\n");
+}
+
+test "failing end-of-stream" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/end-of-stream.input"), error.EndOfStream);
+}
+test "failing invalid-distance" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/invalid-distance.input"), error.InvalidMatch);
+}
+test "failing invalid-tree01" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/invalid-tree01.input"), error.IncompleteHuffmanTree);
+}
+test "failing invalid-tree02" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/invalid-tree02.input"), error.EndOfStream);
+}
+test "failing invalid-tree03" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/invalid-tree03.input"), error.IncompleteHuffmanTree);
+}
+test "failing lengths-overflow" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/lengths-overflow.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing out-of-codes" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/out-of-codes.input"), error.InvalidCode);
+}
+test "failing puff01" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff01.input"), error.WrongStoredBlockNlen);
+}
+test "failing puff02" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff02.input"), error.EndOfStream);
+}
+test "failing puff04" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff04.input"), error.InvalidCode);
+}
+test "failing puff05" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff05.input"), error.EndOfStream);
+}
+test "failing puff06" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff06.input"), error.EndOfStream);
+}
+test "failing puff08" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff08.input"), error.InvalidCode);
+}
+test "failing puff10" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff10.input"), error.InvalidCode);
+}
+test "failing puff11" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff11.input"), error.EndOfStream);
+}
+test "failing puff12" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff12.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing puff13" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff13.input"), error.IncompleteHuffmanTree);
+}
+test "failing puff14" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff14.input"), error.EndOfStream);
+}
+test "failing puff15" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff15.input"), error.IncompleteHuffmanTree);
+}
+test "failing puff16" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff16.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing puff17" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff17.input"), error.MissingEndOfBlockCode);
+}
+test "failing fuzz1" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/fuzz1.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing fuzz2" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/fuzz2.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing fuzz3" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/fuzz3.input"), error.InvalidMatch);
+}
+test "failing fuzz4" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/fuzz4.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff18" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff18.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff19" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff19.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff20" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff20.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff21" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff21.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff22" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff22.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff23" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff23.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff24" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff24.input"), error.IncompleteHuffmanTree);
+}
+test "failing puff25" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff25.input"), error.OversubscribedHuffmanTree);
+}
+test "failing puff26" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff26.input"), error.InvalidDynamicBlockHeader);
+}
+test "failing puff27" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/puff27.input"), error.InvalidDynamicBlockHeader);
+}
+
+test "deflate-stream" {
+    try testDecompress(
+        .raw,
+        @embedFile("testdata/fuzz/deflate-stream.input"),
+        @embedFile("testdata/fuzz/deflate-stream.expect"),
+    );
+}
+
+test "empty-distance-alphabet01" {
+    try testFailure(.raw, @embedFile("testdata/fuzz/empty-distance-alphabet01.input"), error.EndOfStream);
+}
+
+test "empty-distance-alphabet02" {
+    try testDecompress(.raw, @embedFile("testdata/fuzz/empty-distance-alphabet02.input"), "");
+}
+
+test "puff03" {
+    try testDecompress(.raw, @embedFile("testdata/fuzz/puff03.input"), &.{0xa});
+}
+
+test "puff09" {
+    try testDecompress(.raw, @embedFile("testdata/fuzz/puff09.input"), "P");
+}
+
+test "bug 18966" {
+    try testDecompress(
+        .gzip,
+        @embedFile("testdata/fuzz/bug_18966.input"),
+        @embedFile("testdata/fuzz/bug_18966.expect"),
+    );
+}
+
+test "reading into empty buffer" {
+    // Inspired by https://github.com/ziglang/zig/issues/19895
+    const input = &[_]u8{
+        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
+        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
+    };
+    var in: Reader = .fixed(input);
+    var decomp: Decompress = .init(&in, .raw, &.{});
+    const r = &decomp.reader;
+    var bufs: [1][]u8 = .{&.{}};
+    try testing.expectEqual(0, try r.readVec(&bufs));
+}
+
+test "zlib header" {
+    // Truncated header
+    try testFailure(.zlib, &[_]u8{0x78}, error.EndOfStream);
+
+    // Wrong CM
+    try testFailure(.zlib, &[_]u8{ 0x79, 0x94 }, error.BadZlibHeader);
+
+    // Wrong CINFO
+    try testFailure(.zlib, &[_]u8{ 0x88, 0x98 }, error.BadZlibHeader);
+
+    // Truncated checksum
+    try testFailure(.zlib, &[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00 }, error.EndOfStream);
+}
+
+test "gzip header" {
+    // Truncated header
+    try testFailure(.gzip, &[_]u8{ 0x1f, 0x8B }, error.EndOfStream);
+
+    // Wrong CM
+    try testFailure(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x03,
+    }, error.BadGzipHeader);
+
+    // Truncated checksum
+    try testFailure(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00,
+    }, error.EndOfStream);
+
+    // Truncated initial size field
+    try testFailure(.gzip, &[_]u8{
+        0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00,
+    }, error.EndOfStream);
+
+    try testDecompress(.gzip, &[_]u8{
+        // GZIP header
+        0x1f, 0x8b, 0x08, 0x12, 0x00, 0x09, 0x6e, 0x88, 0x00, 0xff, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x00,
+        // header.FHCRC (should cover entire header)
+        0x99, 0xd6,
+        // GZIP data
+        0x01, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    }, "");
+}
+
+test "zlib should not overshoot" {
+    // Compressed zlib data with extra 4 bytes at the end.
+    const data = [_]u8{
+        0x78, 0x9c, 0x73, 0xce, 0x2f, 0xa8, 0x2c, 0xca, 0x4c, 0xcf, 0x28, 0x51, 0x08, 0xcf, 0xcc, 0xc9,
+        0x49, 0xcd, 0x55, 0x28, 0x4b, 0xcc, 0x53, 0x08, 0x4e, 0xce, 0x48, 0xcc, 0xcc, 0xd6, 0x51, 0x08,
+        0xce, 0xcc, 0x4b, 0x4f, 0x2c, 0xc8, 0x2f, 0x4a, 0x55, 0x30, 0xb4, 0xb4, 0x34, 0xd5, 0xb5, 0x34,
+        0x03, 0x00, 0x8b, 0x61, 0x0f, 0xa4, 0x52, 0x5a, 0x94, 0x12,
+    };
+
+    var reader: std.Io.Reader = .fixed(&data);
+
+    var decompress_buffer: [flate.max_window_len]u8 = undefined;
+    var decompress: Decompress = .init(&reader, .zlib, &decompress_buffer);
+    var out: [128]u8 = undefined;
+
+    {
+        const n = try decompress.reader.readSliceShort(&out);
+        try std.testing.expectEqual(46, n);
+        try std.testing.expectEqualStrings("Copyright Willem van Schaik, Singapore 1995-96", out[0..n]);
+    }
+
+    // 4 bytes after compressed chunk are available in reader.
+    const n = try reader.readSliceShort(&out);
+    try std.testing.expectEqual(n, 4);
+    try std.testing.expectEqualSlices(u8, data[data.len - 4 .. data.len], out[0..n]);
+}
+
+fn testFailure(container: Container, in: []const u8, expected_err: anyerror) !void {
+    var reader: Reader = .fixed(in);
+    var aw: Writer.Allocating = .init(testing.allocator);
+    try aw.ensureUnusedCapacity(flate.history_len);
+    defer aw.deinit();
+
+    var decompress: Decompress = .init(&reader, container, &.{});
+    try testing.expectError(error.ReadFailed, decompress.reader.streamRemaining(&aw.writer));
+    try testing.expectEqual(expected_err, decompress.err orelse return error.TestFailed);
+}
+
+fn testDecompress(container: Container, compressed: []const u8, expected_plain: []const u8) !void {
+    var in: std.Io.Reader = .fixed(compressed);
+    var aw: std.Io.Writer.Allocating = .init(testing.allocator);
+    try aw.ensureUnusedCapacity(flate.history_len);
+    defer aw.deinit();
+
+    var decompress: Decompress = .init(&in, container, &.{});
+    _ = try decompress.reader.streamRemaining(&aw.writer);
+    try testing.expectEqualSlices(u8, expected_plain, aw.getWritten());
+}
diff --git a/lib/std/compress/flate/HuffmanEncoder.zig b/lib/std/compress/flate/HuffmanEncoder.zig
new file mode 100644
index 0000000000..28a405b886
--- /dev/null
+++ b/lib/std/compress/flate/HuffmanEncoder.zig
@@ -0,0 +1,463 @@
+const HuffmanEncoder = @This();
+const std = @import("std");
+const assert = std.debug.assert;
+const testing = std.testing;
+
+codes: []Code,
+// Reusable buffer with the longest possible frequency table.
+freq_cache: [max_num_frequencies + 1]LiteralNode,
+bit_count: [17]u32,
+lns: []LiteralNode, // sorted by literal, stored to avoid repeated allocation in generate
+lfs: []LiteralNode, // sorted by frequency, stored to avoid repeated allocation in generate
+
+pub const LiteralNode = struct {
+    literal: u16,
+    freq: u16,
+
+    pub fn max() LiteralNode {
+        return .{
+            .literal = std.math.maxInt(u16),
+            .freq = std.math.maxInt(u16),
+        };
+    }
+};
+
+pub const Code = struct {
+    code: u16 = 0,
+    len: u16 = 0,
+};
+
+/// The odd order in which the codegen code sizes are written.
+pub const codegen_order = [_]u32{ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
+/// The number of codegen codes.
+pub const codegen_code_count = 19;
+
+/// The largest distance code.
+pub const distance_code_count = 30;
+
+/// Maximum number of literals.
+pub const max_num_lit = 286;
+
+/// Max number of frequencies used for a Huffman Code
+/// Possible lengths are codegen_code_count (19), distance_code_count (30) and max_num_lit (286).
+/// The largest of these is max_num_lit.
+pub const max_num_frequencies = max_num_lit;
+
+/// Biggest block size for uncompressed block.
+pub const max_store_block_size = 65535;
+/// The special code used to mark the end of a block.
+pub const end_block_marker = 256;
+
+/// Update this Huffman Code object to be the minimum code for the specified frequency count.
+///
+/// freq  An array of frequencies, in which frequency[i] gives the frequency of literal i.
+/// max_bits  The maximum number of bits to use for any literal.
+pub fn generate(self: *HuffmanEncoder, freq: []u16, max_bits: u32) void {
+    var list = self.freq_cache[0 .. freq.len + 1];
+    // Number of non-zero literals
+    var count: u32 = 0;
+    // Set list to be the set of all non-zero literals and their frequencies
+    for (freq, 0..) |f, i| {
+        if (f != 0) {
+            list[count] = LiteralNode{ .literal = @as(u16, @intCast(i)), .freq = f };
+            count += 1;
+        } else {
+            list[count] = LiteralNode{ .literal = 0x00, .freq = 0 };
+            self.codes[i].len = 0;
+        }
+    }
+    list[freq.len] = LiteralNode{ .literal = 0x00, .freq = 0 };
+
+    list = list[0..count];
+    if (count <= 2) {
+        // Handle the small cases here, because they are awkward for the general case code. With
+        // two or fewer literals, everything has bit length 1.
+        for (list, 0..) |node, i| {
+            // "list" is in order of increasing literal value.
+            self.codes[node.literal] = .{
+                .code = @intCast(i),
+                .len = 1,
+            };
+        }
+        return;
+    }
+    self.lfs = list;
+    std.mem.sort(LiteralNode, self.lfs, {}, byFreq);
+
+    // Get the number of literals for each bit count
+    const bit_count = self.bitCounts(list, max_bits);
+    // And do the assignment
+    self.assignEncodingAndSize(bit_count, list);
+}
+
+pub fn bitLength(self: *HuffmanEncoder, freq: []u16) u32 {
+    var total: u32 = 0;
+    for (freq, 0..) |f, i| {
+        if (f != 0) {
+            total += @as(u32, @intCast(f)) * @as(u32, @intCast(self.codes[i].len));
+        }
+    }
+    return total;
+}
+
+/// Return the number of literals assigned to each bit size in the Huffman encoding
+///
+/// This method is only called when list.len >= 3
+/// The cases of 0, 1, and 2 literals are handled by special case code.
+///
+/// list: An array of the literals with non-zero frequencies
+/// and their associated frequencies. The array is in order of increasing
+/// frequency, and has as its last element a special element with frequency
+/// `math.maxInt(i32)`
+///
+/// max_bits: The maximum number of bits that should be used to encode any literal.
+/// Must be less than 16.
+///
+/// Returns an integer array in which array[i] indicates the number of literals
+/// that should be encoded in i bits.
+fn bitCounts(self: *HuffmanEncoder, list: []LiteralNode, max_bits_to_use: usize) []u32 {
+    var max_bits = max_bits_to_use;
+    const n = list.len;
+    const max_bits_limit = 16;
+
+    assert(max_bits < max_bits_limit);
+
+    // The tree can't have greater depth than n - 1, no matter what. This
+    // saves a little bit of work in some small cases
+    max_bits = @min(max_bits, n - 1);
+
+    // Create information about each of the levels.
+    // A bogus "Level 0" whose sole purpose is so that
+    // level1.prev.needed == 0.  This makes level1.next_pair_freq
+    // be a legitimate value that never gets chosen.
+    var levels: [max_bits_limit]LevelInfo = std.mem.zeroes([max_bits_limit]LevelInfo);
+    // leaf_counts[i] counts the number of literals at the left
+    // of ancestors of the rightmost node at level i.
+    // leaf_counts[i][j] is the number of literals at the left
+    // of the level j ancestor.
+    var leaf_counts: [max_bits_limit][max_bits_limit]u32 = @splat(@splat(0));
+
+    {
+        var level = @as(u32, 1);
+        while (level <= max_bits) : (level += 1) {
+            // For every level, the first two items are the first two characters.
+            // We initialize the levels as if we had already figured this out.
+            levels[level] = LevelInfo{
+                .level = level,
+                .last_freq = list[1].freq,
+                .next_char_freq = list[2].freq,
+                .next_pair_freq = list[0].freq + list[1].freq,
+                .needed = 0,
+            };
+            leaf_counts[level][level] = 2;
+            if (level == 1) {
+                levels[level].next_pair_freq = std.math.maxInt(i32);
+            }
+        }
+    }
+
+    // We need a total of 2*n - 2 items at top level and have already generated 2.
+    levels[max_bits].needed = 2 * @as(u32, @intCast(n)) - 4;
+
+    {
+        var level = max_bits;
+        while (true) {
+            var l = &levels[level];
+            if (l.next_pair_freq == std.math.maxInt(i32) and l.next_char_freq == std.math.maxInt(i32)) {
+                // We've run out of both leaves and pairs.
+                // End all calculations for this level.
+                // To make sure we never come back to this level or any lower level,
+                // set next_pair_freq impossibly large.
+                l.needed = 0;
+                levels[level + 1].next_pair_freq = std.math.maxInt(i32);
+                level += 1;
+                continue;
+            }
+
+            const prev_freq = l.last_freq;
+            if (l.next_char_freq < l.next_pair_freq) {
+                // The next item on this row is a leaf node.
+                const next = leaf_counts[level][level] + 1;
+                l.last_freq = l.next_char_freq;
+                // Lower leaf_counts are the same of the previous node.
+                leaf_counts[level][level] = next;
+                if (next >= list.len) {
+                    l.next_char_freq = LiteralNode.max().freq;
+                } else {
+                    l.next_char_freq = list[next].freq;
+                }
+            } else {
+                // The next item on this row is a pair from the previous row.
+                // next_pair_freq isn't valid until we generate two
+                // more values in the level below
+                l.last_freq = l.next_pair_freq;
+                // Take leaf counts from the lower level, except counts[level] remains the same.
+                @memcpy(leaf_counts[level][0..level], leaf_counts[level - 1][0..level]);
+                levels[l.level - 1].needed = 2;
+            }
+
+            l.needed -= 1;
+            if (l.needed == 0) {
+                // We've done everything we need to do for this level.
+                // Continue calculating one level up. Fill in next_pair_freq
+                // of that level with the sum of the two nodes we've just calculated on
+                // this level.
+                if (l.level == max_bits) {
+                    // All done!
+                    break;
+                }
+                levels[l.level + 1].next_pair_freq = prev_freq + l.last_freq;
+                level += 1;
+            } else {
+                // If we stole from below, move down temporarily to replenish it.
+                while (levels[level - 1].needed > 0) {
+                    level -= 1;
+                    if (level == 0) {
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    // Somethings is wrong if at the end, the top level is null or hasn't used
+    // all of the leaves.
+    assert(leaf_counts[max_bits][max_bits] == n);
+
+    var bit_count = self.bit_count[0 .. max_bits + 1];
+    var bits: u32 = 1;
+    const counts = &leaf_counts[max_bits];
+    {
+        var level = max_bits;
+        while (level > 0) : (level -= 1) {
+            // counts[level] gives the number of literals requiring at least "bits"
+            // bits to encode.
+            bit_count[bits] = counts[level] - counts[level - 1];
+            bits += 1;
+            if (level == 0) {
+                break;
+            }
+        }
+    }
+    return bit_count;
+}
+
+/// Look at the leaves and assign them a bit count and an encoding as specified
+/// in RFC 1951 3.2.2
+fn assignEncodingAndSize(self: *HuffmanEncoder, bit_count: []u32, list_arg: []LiteralNode) void {
+    var code = @as(u16, 0);
+    var list = list_arg;
+
+    for (bit_count, 0..) |bits, n| {
+        code <<= 1;
+        if (n == 0 or bits == 0) {
+            continue;
+        }
+        // The literals list[list.len-bits] .. list[list.len-bits]
+        // are encoded using "bits" bits, and get the values
+        // code, code + 1, ....  The code values are
+        // assigned in literal order (not frequency order).
+        const chunk = list[list.len - @as(u32, @intCast(bits)) ..];
+
+        self.lns = chunk;
+        std.mem.sort(LiteralNode, self.lns, {}, byLiteral);
+
+        for (chunk) |node| {
+            self.codes[node.literal] = .{
+                .code = bitReverse(u16, code, @as(u5, @intCast(n))),
+                .len = @as(u16, @intCast(n)),
+            };
+            code += 1;
+        }
+        list = list[0 .. list.len - @as(u32, @intCast(bits))];
+    }
+}
+
+fn byFreq(context: void, a: LiteralNode, b: LiteralNode) bool {
+    _ = context;
+    if (a.freq == b.freq) {
+        return a.literal < b.literal;
+    }
+    return a.freq < b.freq;
+}
+
+/// Describes the state of the constructed tree for a given depth.
+const LevelInfo = struct {
+    /// Our level.  for better printing
+    level: u32,
+    /// The frequency of the last node at this level
+    last_freq: u32,
+    /// The frequency of the next character to add to this level
+    next_char_freq: u32,
+    /// The frequency of the next pair (from level below) to add to this level.
+    /// Only valid if the "needed" value of the next lower level is 0.
+    next_pair_freq: u32,
+    /// The number of chains remaining to generate for this level before moving
+    /// up to the next level
+    needed: u32,
+};
+
+fn byLiteral(context: void, a: LiteralNode, b: LiteralNode) bool {
+    _ = context;
+    return a.literal < b.literal;
+}
+
+/// Reverse bit-by-bit a N-bit code.
+fn bitReverse(comptime T: type, value: T, n: usize) T {
+    const r = @bitReverse(value);
+    return r >> @as(std.math.Log2Int(T), @intCast(@typeInfo(T).int.bits - n));
+}
+
+test bitReverse {
+    const ReverseBitsTest = struct {
+        in: u16,
+        bit_count: u5,
+        out: u16,
+    };
+
+    const reverse_bits_tests = [_]ReverseBitsTest{
+        .{ .in = 1, .bit_count = 1, .out = 1 },
+        .{ .in = 1, .bit_count = 2, .out = 2 },
+        .{ .in = 1, .bit_count = 3, .out = 4 },
+        .{ .in = 1, .bit_count = 4, .out = 8 },
+        .{ .in = 1, .bit_count = 5, .out = 16 },
+        .{ .in = 17, .bit_count = 5, .out = 17 },
+        .{ .in = 257, .bit_count = 9, .out = 257 },
+        .{ .in = 29, .bit_count = 5, .out = 23 },
+    };
+
+    for (reverse_bits_tests) |h| {
+        const v = bitReverse(u16, h.in, h.bit_count);
+        try std.testing.expectEqual(h.out, v);
+    }
+}
+
+/// Generates a HuffmanCode corresponding to the fixed literal table
+pub fn fixedLiteralEncoder(codes: *[max_num_frequencies]Code) HuffmanEncoder {
+    var h: HuffmanEncoder = undefined;
+    h.codes = codes;
+    var ch: u16 = 0;
+
+    while (ch < max_num_frequencies) : (ch += 1) {
+        var bits: u16 = undefined;
+        var size: u16 = undefined;
+        switch (ch) {
+            0...143 => {
+                // size 8, 000110000  .. 10111111
+                bits = ch + 48;
+                size = 8;
+            },
+            144...255 => {
+                // size 9, 110010000 .. 111111111
+                bits = ch + 400 - 144;
+                size = 9;
+            },
+            256...279 => {
+                // size 7, 0000000 .. 0010111
+                bits = ch - 256;
+                size = 7;
+            },
+            else => {
+                // size 8, 11000000 .. 11000111
+                bits = ch + 192 - 280;
+                size = 8;
+            },
+        }
+        h.codes[ch] = .{ .code = bitReverse(u16, bits, @as(u5, @intCast(size))), .len = size };
+    }
+    return h;
+}
+
+pub fn fixedDistanceEncoder(codes: *[distance_code_count]Code) HuffmanEncoder {
+    var h: HuffmanEncoder = undefined;
+    h.codes = codes;
+    for (h.codes, 0..) |_, ch| {
+        h.codes[ch] = .{ .code = bitReverse(u16, @as(u16, @intCast(ch)), 5), .len = 5 };
+    }
+    return h;
+}
+
+pub fn huffmanDistanceEncoder(codes: *[distance_code_count]Code) HuffmanEncoder {
+    var distance_freq: [distance_code_count]u16 = @splat(0);
+    distance_freq[0] = 1;
+    // huff_distance is a static distance encoder used for huffman only encoding.
+    // It can be reused since we will not be encoding distance values.
+    var h: HuffmanEncoder = .{};
+    h.codes = codes;
+    h.generate(distance_freq[0..], 15);
+    return h;
+}
+
+test "generate a Huffman code for the fixed literal table specific to Deflate" {
+    var codes: [max_num_frequencies]Code = undefined;
+    const enc: HuffmanEncoder = .fixedLiteralEncoder(&codes);
+    for (enc.codes) |c| {
+        switch (c.len) {
+            7 => {
+                const v = @bitReverse(@as(u7, @intCast(c.code)));
+                try testing.expect(v <= 0b0010111);
+            },
+            8 => {
+                const v = @bitReverse(@as(u8, @intCast(c.code)));
+                try testing.expect((v >= 0b000110000 and v <= 0b10111111) or
+                    (v >= 0b11000000 and v <= 11000111));
+            },
+            9 => {
+                const v = @bitReverse(@as(u9, @intCast(c.code)));
+                try testing.expect(v >= 0b110010000 and v <= 0b111111111);
+            },
+            else => unreachable,
+        }
+    }
+}
+
+test "generate a Huffman code for the 30 possible relative distances (LZ77 distances) of Deflate" {
+    var codes: [distance_code_count]Code = undefined;
+    const enc = fixedDistanceEncoder(&codes);
+    for (enc.codes) |c| {
+        const v = @bitReverse(@as(u5, @intCast(c.code)));
+        try testing.expect(v <= 29);
+        try testing.expect(c.len == 5);
+    }
+}
+
+pub const fixed_codes = [_]u8{
+    0b00001100, 0b10001100, 0b01001100, 0b11001100, 0b00101100, 0b10101100, 0b01101100, 0b11101100,
+    0b00011100, 0b10011100, 0b01011100, 0b11011100, 0b00111100, 0b10111100, 0b01111100, 0b11111100,
+    0b00000010, 0b10000010, 0b01000010, 0b11000010, 0b00100010, 0b10100010, 0b01100010, 0b11100010,
+    0b00010010, 0b10010010, 0b01010010, 0b11010010, 0b00110010, 0b10110010, 0b01110010, 0b11110010,
+    0b00001010, 0b10001010, 0b01001010, 0b11001010, 0b00101010, 0b10101010, 0b01101010, 0b11101010,
+    0b00011010, 0b10011010, 0b01011010, 0b11011010, 0b00111010, 0b10111010, 0b01111010, 0b11111010,
+    0b00000110, 0b10000110, 0b01000110, 0b11000110, 0b00100110, 0b10100110, 0b01100110, 0b11100110,
+    0b00010110, 0b10010110, 0b01010110, 0b11010110, 0b00110110, 0b10110110, 0b01110110, 0b11110110,
+    0b00001110, 0b10001110, 0b01001110, 0b11001110, 0b00101110, 0b10101110, 0b01101110, 0b11101110,
+    0b00011110, 0b10011110, 0b01011110, 0b11011110, 0b00111110, 0b10111110, 0b01111110, 0b11111110,
+    0b00000001, 0b10000001, 0b01000001, 0b11000001, 0b00100001, 0b10100001, 0b01100001, 0b11100001,
+    0b00010001, 0b10010001, 0b01010001, 0b11010001, 0b00110001, 0b10110001, 0b01110001, 0b11110001,
+    0b00001001, 0b10001001, 0b01001001, 0b11001001, 0b00101001, 0b10101001, 0b01101001, 0b11101001,
+    0b00011001, 0b10011001, 0b01011001, 0b11011001, 0b00111001, 0b10111001, 0b01111001, 0b11111001,
+    0b00000101, 0b10000101, 0b01000101, 0b11000101, 0b00100101, 0b10100101, 0b01100101, 0b11100101,
+    0b00010101, 0b10010101, 0b01010101, 0b11010101, 0b00110101, 0b10110101, 0b01110101, 0b11110101,
+    0b00001101, 0b10001101, 0b01001101, 0b11001101, 0b00101101, 0b10101101, 0b01101101, 0b11101101,
+    0b00011101, 0b10011101, 0b01011101, 0b11011101, 0b00111101, 0b10111101, 0b01111101, 0b11111101,
+    0b00010011, 0b00100110, 0b01001110, 0b10011010, 0b00111100, 0b01100101, 0b11101010, 0b10110100,
+    0b11101001, 0b00110011, 0b01100110, 0b11001110, 0b10011010, 0b00111101, 0b01100111, 0b11101110,
+    0b10111100, 0b11111001, 0b00001011, 0b00010110, 0b00101110, 0b01011010, 0b10111100, 0b01100100,
+    0b11101001, 0b10110010, 0b11100101, 0b00101011, 0b01010110, 0b10101110, 0b01011010, 0b10111101,
+    0b01100110, 0b11101101, 0b10111010, 0b11110101, 0b00011011, 0b00110110, 0b01101110, 0b11011010,
+    0b10111100, 0b01100101, 0b11101011, 0b10110110, 0b11101101, 0b00111011, 0b01110110, 0b11101110,
+    0b11011010, 0b10111101, 0b01100111, 0b11101111, 0b10111110, 0b11111101, 0b00000111, 0b00001110,
+    0b00011110, 0b00111010, 0b01111100, 0b11100100, 0b11101000, 0b10110001, 0b11100011, 0b00100111,
+    0b01001110, 0b10011110, 0b00111010, 0b01111101, 0b11100110, 0b11101100, 0b10111001, 0b11110011,
+    0b00010111, 0b00101110, 0b01011110, 0b10111010, 0b01111100, 0b11100101, 0b11101010, 0b10110101,
+    0b11101011, 0b00110111, 0b01101110, 0b11011110, 0b10111010, 0b01111101, 0b11100111, 0b11101110,
+    0b10111101, 0b11111011, 0b00001111, 0b00011110, 0b00111110, 0b01111010, 0b11111100, 0b11100100,
+    0b11101001, 0b10110011, 0b11100111, 0b00101111, 0b01011110, 0b10111110, 0b01111010, 0b11111101,
+    0b11100110, 0b11101101, 0b10111011, 0b11110111, 0b00011111, 0b00111110, 0b01111110, 0b11111010,
+    0b11111100, 0b11100101, 0b11101011, 0b10110111, 0b11101111, 0b00111111, 0b01111110, 0b11111110,
+    0b11111010, 0b11111101, 0b11100111, 0b11101111, 0b10111111, 0b11111111, 0b00000000, 0b00100000,
+    0b00001000, 0b00001100, 0b10000001, 0b11000010, 0b11100000, 0b00001000, 0b00100100, 0b00001010,
+    0b10001101, 0b11000001, 0b11100010, 0b11110000, 0b00000100, 0b00100010, 0b10001001, 0b01001100,
+    0b10100001, 0b11010010, 0b11101000, 0b00000011, 0b10000011, 0b01000011, 0b11000011, 0b00100011,
+    0b10100011,
+};
diff --git a/lib/std/compress/flate/Lookup.zig b/lib/std/compress/flate/Lookup.zig
index 90d0341bca..d1d93de50a 100644
--- a/lib/std/compress/flate/Lookup.zig
+++ b/lib/std/compress/flate/Lookup.zig
@@ -5,22 +5,27 @@
 const std = @import("std");
 const testing = std.testing;
 const expect = testing.expect;
-const consts = @import("consts.zig");
+const flate = @import("../flate.zig");
+const Token = @import("Token.zig");
 
-const Self = @This();
+const Lookup = @This();
 
 const prime4 = 0x9E3779B1; // 4 bytes prime number 2654435761
-const chain_len = 2 * consts.history.len;
+const chain_len = 2 * flate.history_len;
+
+pub const bits = 15;
+pub const len = 1 << bits;
+pub const shift = 32 - bits;
 
 // Maps hash => first position
-head: [consts.lookup.len]u16 = [_]u16{0} ** consts.lookup.len,
+head: [len]u16 = [_]u16{0} ** len,
 // Maps position => previous positions for the same hash value
 chain: [chain_len]u16 = [_]u16{0} ** (chain_len),
 
 // Calculates hash of the 4 bytes from data.
 // Inserts `pos` position of that hash in the lookup tables.
 // Returns previous location with the same hash value.
-pub fn add(self: *Self, data: []const u8, pos: u16) u16 {
+pub fn add(self: *Lookup, data: []const u8, pos: u16) u16 {
     if (data.len < 4) return 0;
     const h = hash(data[0..4]);
     return self.set(h, pos);
@@ -28,11 +33,11 @@ pub fn add(self: *Self, data: []const u8, pos: u16) u16 {
 
 // Returns previous location with the same hash value given the current
 // position.
-pub fn prev(self: *Self, pos: u16) u16 {
+pub fn prev(self: *Lookup, pos: u16) u16 {
     return self.chain[pos];
 }
 
-fn set(self: *Self, h: u32, pos: u16) u16 {
+fn set(self: *Lookup, h: u32, pos: u16) u16 {
     const p = self.head[h];
     self.head[h] = pos;
     self.chain[pos] = p;
@@ -40,7 +45,7 @@ fn set(self: *Self, h: u32, pos: u16) u16 {
 }
 
 // Slide all positions in head and chain for `n`
-pub fn slide(self: *Self, n: u16) void {
+pub fn slide(self: *Lookup, n: u16) void {
     for (&self.head) |*v| {
         v.* -|= n;
     }
@@ -52,8 +57,8 @@ pub fn slide(self: *Self, n: u16) void {
 
 // Add `len` 4 bytes hashes from `data` into lookup.
 // Position of the first byte is `pos`.
-pub fn bulkAdd(self: *Self, data: []const u8, len: u16, pos: u16) void {
-    if (len == 0 or data.len < consts.match.min_length) {
+pub fn bulkAdd(self: *Lookup, data: []const u8, length: u16, pos: u16) void {
+    if (length == 0 or data.len < Token.min_length) {
         return;
     }
     var hb =
@@ -64,7 +69,7 @@ pub fn bulkAdd(self: *Self, data: []const u8, len: u16, pos: u16) void {
     _ = self.set(hashu(hb), pos);
 
     var i = pos;
-    for (4..@min(len + 3, data.len)) |j| {
+    for (4..@min(length + 3, data.len)) |j| {
         hb = (hb << 8) | @as(u32, data[j]);
         i += 1;
         _ = self.set(hashu(hb), i);
@@ -80,7 +85,7 @@ fn hash(b: *const [4]u8) u32 {
 }
 
 fn hashu(v: u32) u32 {
-    return @intCast((v *% prime4) >> consts.lookup.shift);
+    return @intCast((v *% prime4) >> shift);
 }
 
 test add {
@@ -91,7 +96,7 @@ test add {
         0x01, 0x02, 0x03,
     };
 
-    var h: Self = .{};
+    var h: Lookup = .{};
     for (data, 0..) |_, i| {
         const p = h.add(data[i..], @intCast(i));
         if (i >= 8 and i < 24) {
@@ -101,7 +106,7 @@ test add {
         }
     }
 
-    const v = Self.hash(data[2 .. 2 + 4]);
+    const v = Lookup.hash(data[2 .. 2 + 4]);
     try expect(h.head[v] == 2 + 16);
     try expect(h.chain[2 + 16] == 2 + 8);
     try expect(h.chain[2 + 8] == 2);
@@ -111,13 +116,13 @@ test bulkAdd {
     const data = "Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
 
     // one by one
-    var h: Self = .{};
+    var h: Lookup = .{};
     for (data, 0..) |_, i| {
         _ = h.add(data[i..], @intCast(i));
     }
 
     // in bulk
-    var bh: Self = .{};
+    var bh: Lookup = .{};
     bh.bulkAdd(data, data.len, 0);
 
     try testing.expectEqualSlices(u16, &h.head, &bh.head);
diff --git a/lib/std/compress/flate/SlidingWindow.zig b/lib/std/compress/flate/SlidingWindow.zig
deleted file mode 100644
index ece907c32f..0000000000
--- a/lib/std/compress/flate/SlidingWindow.zig
+++ /dev/null
@@ -1,160 +0,0 @@
-//! Used in deflate (compression), holds uncompressed data form which Tokens are
-//! produces. In combination with Lookup it is used to find matches in history data.
-//!
-const std = @import("std");
-const consts = @import("consts.zig");
-
-const expect = testing.expect;
-const assert = std.debug.assert;
-const testing = std.testing;
-
-const hist_len = consts.history.len;
-const buffer_len = 2 * hist_len;
-const min_lookahead = consts.match.min_length + consts.match.max_length;
-const max_rp = buffer_len - min_lookahead;
-
-const Self = @This();
-
-buffer: [buffer_len]u8 = undefined,
-wp: usize = 0, // write position
-rp: usize = 0, // read position
-fp: isize = 0, // last flush position, tokens are build from fp..rp
-
-/// Returns number of bytes written, or 0 if buffer is full and need to slide.
-pub fn write(self: *Self, buf: []const u8) usize {
-    if (self.rp >= max_rp) return 0; // need to slide
-
-    const n = @min(buf.len, buffer_len - self.wp);
-    @memcpy(self.buffer[self.wp .. self.wp + n], buf[0..n]);
-    self.wp += n;
-    return n;
-}
-
-/// Slide buffer for hist_len.
-/// Drops old history, preserves between hist_len and hist_len - min_lookahead.
-/// Returns number of bytes removed.
-pub fn slide(self: *Self) u16 {
-    assert(self.rp >= max_rp and self.wp >= self.rp);
-    const n = self.wp - hist_len;
-    @memcpy(self.buffer[0..n], self.buffer[hist_len..self.wp]);
-    self.rp -= hist_len;
-    self.wp -= hist_len;
-    self.fp -= hist_len;
-    return @intCast(n);
-}
-
-/// Data from the current position (read position). Those part of the buffer is
-/// not converted to tokens yet.
-fn lookahead(self: *Self) []const u8 {
-    assert(self.wp >= self.rp);
-    return self.buffer[self.rp..self.wp];
-}
-
-/// Returns part of the lookahead buffer. If should_flush is set no lookahead is
-/// preserved otherwise preserves enough data for the longest match. Returns
-/// null if there is not enough data.
-pub fn activeLookahead(self: *Self, should_flush: bool) ?[]const u8 {
-    const min: usize = if (should_flush) 0 else min_lookahead;
-    const lh = self.lookahead();
-    return if (lh.len > min) lh else null;
-}
-
-/// Advances read position, shrinks lookahead.
-pub fn advance(self: *Self, n: u16) void {
-    assert(self.wp >= self.rp + n);
-    self.rp += n;
-}
-
-/// Returns writable part of the buffer, where new uncompressed data can be
-/// written.
-pub fn writable(self: *Self) []u8 {
-    return self.buffer[self.wp..];
-}
-
-/// Notification of what part of writable buffer is filled with data.
-pub fn written(self: *Self, n: usize) void {
-    self.wp += n;
-}
-
-/// Finds match length between previous and current position.
-/// Used in hot path!
-pub fn match(self: *Self, prev_pos: u16, curr_pos: u16, min_len: u16) u16 {
-    const max_len: usize = @min(self.wp - curr_pos, consts.match.max_length);
-    // lookahead buffers from previous and current positions
-    const prev_lh = self.buffer[prev_pos..][0..max_len];
-    const curr_lh = self.buffer[curr_pos..][0..max_len];
-
-    // If we already have match (min_len > 0),
-    // test the first byte above previous len a[min_len] != b[min_len]
-    // and then all the bytes from that position to zero.
-    // That is likely positions to find difference than looping from first bytes.
-    var i: usize = min_len;
-    if (i > 0) {
-        if (max_len <= i) return 0;
-        while (true) {
-            if (prev_lh[i] != curr_lh[i]) return 0;
-            if (i == 0) break;
-            i -= 1;
-        }
-        i = min_len;
-    }
-    while (i < max_len) : (i += 1)
-        if (prev_lh[i] != curr_lh[i]) break;
-    return if (i >= consts.match.min_length) @intCast(i) else 0;
-}
-
-/// Current position of non-compressed data. Data before rp are already converted
-/// to tokens.
-pub fn pos(self: *Self) u16 {
-    return @intCast(self.rp);
-}
-
-/// Notification that token list is cleared.
-pub fn flush(self: *Self) void {
-    self.fp = @intCast(self.rp);
-}
-
-/// Part of the buffer since last flush or null if there was slide in between (so
-/// fp becomes negative).
-pub fn tokensBuffer(self: *Self) ?[]const u8 {
-    assert(self.fp <= self.rp);
-    if (self.fp < 0) return null;
-    return self.buffer[@intCast(self.fp)..self.rp];
-}
-
-test match {
-    const data = "Blah blah blah blah blah!";
-    var win: Self = .{};
-    try expect(win.write(data) == data.len);
-    try expect(win.wp == data.len);
-    try expect(win.rp == 0);
-
-    // length between l symbols
-    try expect(win.match(1, 6, 0) == 18);
-    try expect(win.match(1, 11, 0) == 13);
-    try expect(win.match(1, 16, 0) == 8);
-    try expect(win.match(1, 21, 0) == 0);
-
-    // position 15 = "blah blah!"
-    // position 20 = "blah!"
-    try expect(win.match(15, 20, 0) == 4);
-    try expect(win.match(15, 20, 3) == 4);
-    try expect(win.match(15, 20, 4) == 0);
-}
-
-test slide {
-    var win: Self = .{};
-    win.wp = Self.buffer_len - 11;
-    win.rp = Self.buffer_len - 111;
-    win.buffer[win.rp] = 0xab;
-    try expect(win.lookahead().len == 100);
-    try expect(win.tokensBuffer().?.len == win.rp);
-
-    const n = win.slide();
-    try expect(n == 32757);
-    try expect(win.buffer[win.rp] == 0xab);
-    try expect(win.rp == Self.hist_len - 111);
-    try expect(win.wp == Self.hist_len - 11);
-    try expect(win.lookahead().len == 100);
-    try expect(win.tokensBuffer() == null);
-}
diff --git a/lib/std/compress/flate/Token.zig b/lib/std/compress/flate/Token.zig
index a9641f6adc..1383047693 100644
--- a/lib/std/compress/flate/Token.zig
+++ b/lib/std/compress/flate/Token.zig
@@ -6,7 +6,6 @@ const std = @import("std");
 const assert = std.debug.assert;
 const print = std.debug.print;
 const expect = std.testing.expect;
-const consts = @import("consts.zig").match;
 
 const Token = @This();
 
@@ -21,16 +20,23 @@ dist: u15 = 0,
 len_lit: u8 = 0,
 kind: Kind = .literal,
 
+pub const base_length = 3; // smallest match length per the RFC section 3.2.5
+pub const min_length = 4; // min length used in this algorithm
+pub const max_length = 258;
+
+pub const min_distance = 1;
+pub const max_distance = std.compress.flate.history_len;
+
 pub fn literal(t: Token) u8 {
     return t.len_lit;
 }
 
 pub fn distance(t: Token) u16 {
-    return @as(u16, t.dist) + consts.min_distance;
+    return @as(u16, t.dist) + min_distance;
 }
 
 pub fn length(t: Token) u16 {
-    return @as(u16, t.len_lit) + consts.base_length;
+    return @as(u16, t.len_lit) + base_length;
 }
 
 pub fn initLiteral(lit: u8) Token {
@@ -40,12 +46,12 @@ pub fn initLiteral(lit: u8) Token {
 // distance range 1 - 32768, stored in dist as 0 - 32767 (u15)
 // length range 3 - 258, stored in len_lit as 0 - 255 (u8)
 pub fn initMatch(dist: u16, len: u16) Token {
-    assert(len >= consts.min_length and len <= consts.max_length);
-    assert(dist >= consts.min_distance and dist <= consts.max_distance);
+    assert(len >= min_length and len <= max_length);
+    assert(dist >= min_distance and dist <= max_distance);
     return .{
         .kind = .match,
-        .dist = @intCast(dist - consts.min_distance),
-        .len_lit = @intCast(len - consts.base_length),
+        .dist = @intCast(dist - min_distance),
+        .len_lit = @intCast(len - base_length),
     };
 }
 
diff --git a/lib/std/compress/flate/bit_reader.zig b/lib/std/compress/flate/bit_reader.zig
deleted file mode 100644
index 1e41f081c1..0000000000
--- a/lib/std/compress/flate/bit_reader.zig
+++ /dev/null
@@ -1,422 +0,0 @@
-const std = @import("std");
-const assert = std.debug.assert;
-const testing = std.testing;
-
-pub fn bitReader(comptime T: type, reader: anytype) BitReader(T, @TypeOf(reader)) {
-    return BitReader(T, @TypeOf(reader)).init(reader);
-}
-
-pub fn BitReader64(comptime ReaderType: type) type {
-    return BitReader(u64, ReaderType);
-}
-
-pub fn BitReader32(comptime ReaderType: type) type {
-    return BitReader(u32, ReaderType);
-}
-
-/// Bit reader used during inflate (decompression). Has internal buffer of 64
-/// bits which shifts right after bits are consumed. Uses forward_reader to fill
-/// that internal buffer when needed.
-///
-/// readF is the core function. Supports few different ways of getting bits
-/// controlled by flags. In hot path we try to avoid checking whether we need to
-/// fill buffer from forward_reader by calling fill in advance and readF with
-/// buffered flag set.
-///
-pub fn BitReader(comptime T: type, comptime ReaderType: type) type {
-    assert(T == u32 or T == u64);
-    const t_bytes: usize = @sizeOf(T);
-    const Tshift = if (T == u64) u6 else u5;
-
-    return struct {
-        // Underlying reader used for filling internal bits buffer
-        forward_reader: ReaderType = undefined,
-        // Internal buffer of 64 bits
-        bits: T = 0,
-        // Number of bits in the buffer
-        nbits: u32 = 0,
-
-        const Self = @This();
-
-        pub const Error = ReaderType.Error || error{EndOfStream};
-
-        pub fn init(rdr: ReaderType) Self {
-            var self = Self{ .forward_reader = rdr };
-            self.fill(1) catch {};
-            return self;
-        }
-
-        /// Try to have `nice` bits are available in buffer. Reads from
-        /// forward reader if there is no `nice` bits in buffer. Returns error
-        /// if end of forward stream is reached and internal buffer is empty.
-        /// It will not error if less than `nice` bits are in buffer, only when
-        /// all bits are exhausted. During inflate we usually know what is the
-        /// maximum bits for the next step but usually that step will need less
-        /// bits to decode. So `nice` is not hard limit, it will just try to have
-        /// that number of bits available. If end of forward stream is reached
-        /// it may be some extra zero bits in buffer.
-        pub inline fn fill(self: *Self, nice: u6) !void {
-            if (self.nbits >= nice and nice != 0) {
-                return; // We have enough bits
-            }
-            // Read more bits from forward reader
-
-            // Number of empty bytes in bits, round nbits to whole bytes.
-            const empty_bytes =
-                @as(u8, if (self.nbits & 0x7 == 0) t_bytes else t_bytes - 1) - // 8 for 8, 16, 24..., 7 otherwise
-                (self.nbits >> 3); // 0 for 0-7, 1 for 8-16, ... same as / 8
-
-            var buf: [t_bytes]u8 = [_]u8{0} ** t_bytes;
-            const bytes_read = self.forward_reader.readAll(buf[0..empty_bytes]) catch 0;
-            if (bytes_read > 0) {
-                const u: T = std.mem.readInt(T, buf[0..t_bytes], .little);
-                self.bits |= u << @as(Tshift, @intCast(self.nbits));
-                self.nbits += 8 * @as(u8, @intCast(bytes_read));
-                return;
-            }
-
-            if (self.nbits == 0)
-                return error.EndOfStream;
-        }
-
-        /// Read exactly buf.len bytes into buf.
-        pub fn readAll(self: *Self, buf: []u8) !void {
-            assert(self.alignBits() == 0); // internal bits must be at byte boundary
-
-            // First read from internal bits buffer.
-            var n: usize = 0;
-            while (self.nbits > 0 and n < buf.len) {
-                buf[n] = try self.readF(u8, flag.buffered);
-                n += 1;
-            }
-            // Then use forward reader for all other bytes.
-            try self.forward_reader.readNoEof(buf[n..]);
-        }
-
-        pub const flag = struct {
-            pub const peek: u3 = 0b001; // dont advance internal buffer, just get bits, leave them in buffer
-            pub const buffered: u3 = 0b010; // assume that there is no need to fill, fill should be called before
-            pub const reverse: u3 = 0b100; // bit reverse read bits
-        };
-
-        /// Alias for readF(U, 0).
-        pub fn read(self: *Self, comptime U: type) !U {
-            return self.readF(U, 0);
-        }
-
-        /// Alias for readF with flag.peak set.
-        pub inline fn peekF(self: *Self, comptime U: type, comptime how: u3) !U {
-            return self.readF(U, how | flag.peek);
-        }
-
-        /// Read with flags provided.
-        pub fn readF(self: *Self, comptime U: type, comptime how: u3) !U {
-            if (U == T) {
-                assert(how == 0);
-                assert(self.alignBits() == 0);
-                try self.fill(@bitSizeOf(T));
-                if (self.nbits != @bitSizeOf(T)) return error.EndOfStream;
-                const v = self.bits;
-                self.nbits = 0;
-                self.bits = 0;
-                return v;
-            }
-            const n: Tshift = @bitSizeOf(U);
-            switch (how) {
-                0 => { // `normal` read
-                    try self.fill(n); // ensure that there are n bits in the buffer
-                    const u: U = @truncate(self.bits); // get n bits
-                    try self.shift(n); // advance buffer for n
-                    return u;
-                },
-                (flag.peek) => { // no shift, leave bits in the buffer
-                    try self.fill(n);
-                    return @truncate(self.bits);
-                },
-                flag.buffered => { // no fill, assume that buffer has enough bits
-                    const u: U = @truncate(self.bits);
-                    try self.shift(n);
-                    return u;
-                },
-                (flag.reverse) => { // same as 0 with bit reverse
-                    try self.fill(n);
-                    const u: U = @truncate(self.bits);
-                    try self.shift(n);
-                    return @bitReverse(u);
-                },
-                (flag.peek | flag.reverse) => {
-                    try self.fill(n);
-                    return @bitReverse(@as(U, @truncate(self.bits)));
-                },
-                (flag.buffered | flag.reverse) => {
-                    const u: U = @truncate(self.bits);
-                    try self.shift(n);
-                    return @bitReverse(u);
-                },
-                (flag.peek | flag.buffered) => {
-                    return @truncate(self.bits);
-                },
-                (flag.peek | flag.buffered | flag.reverse) => {
-                    return @bitReverse(@as(U, @truncate(self.bits)));
-                },
-            }
-        }
-
-        /// Read n number of bits.
-        /// Only buffered flag can be used in how.
-        pub fn readN(self: *Self, n: u4, comptime how: u3) !u16 {
-            switch (how) {
-                0 => {
-                    try self.fill(n);
-                },
-                flag.buffered => {},
-                else => unreachable,
-            }
-            const mask: u16 = (@as(u16, 1) << n) - 1;
-            const u: u16 = @as(u16, @truncate(self.bits)) & mask;
-            try self.shift(n);
-            return u;
-        }
-
-        /// Advance buffer for n bits.
-        pub fn shift(self: *Self, n: Tshift) !void {
-            if (n > self.nbits) return error.EndOfStream;
-            self.bits >>= n;
-            self.nbits -= n;
-        }
-
-        /// Skip n bytes.
-        pub fn skipBytes(self: *Self, n: u16) !void {
-            for (0..n) |_| {
-                try self.fill(8);
-                try self.shift(8);
-            }
-        }
-
-        // Number of bits to align stream to the byte boundary.
-        fn alignBits(self: *Self) u3 {
-            return @intCast(self.nbits & 0x7);
-        }
-
-        /// Align stream to the byte boundary.
-        pub fn alignToByte(self: *Self) void {
-            const ab = self.alignBits();
-            if (ab > 0) self.shift(ab) catch unreachable;
-        }
-
-        /// Skip zero terminated string.
-        pub fn skipStringZ(self: *Self) !void {
-            while (true) {
-                if (try self.readF(u8, 0) == 0) break;
-            }
-        }
-
-        /// Read deflate fixed fixed code.
-        /// Reads first 7 bits, and then maybe 1 or 2 more to get full 7,8 or 9 bit code.
-        /// ref: https://datatracker.ietf.org/doc/html/rfc1951#page-12
-        ///         Lit Value    Bits        Codes
-        ///          ---------    ----        -----
-        ///            0 - 143     8          00110000 through
-        ///                                   10111111
-        ///          144 - 255     9          110010000 through
-        ///                                   111111111
-        ///          256 - 279     7          0000000 through
-        ///                                   0010111
-        ///          280 - 287     8          11000000 through
-        ///                                   11000111
-        pub fn readFixedCode(self: *Self) !u16 {
-            try self.fill(7 + 2);
-            const code7 = try self.readF(u7, flag.buffered | flag.reverse);
-            if (code7 <= 0b0010_111) { // 7 bits, 256-279, codes 0000_000 - 0010_111
-                return @as(u16, code7) + 256;
-            } else if (code7 <= 0b1011_111) { // 8 bits, 0-143, codes 0011_0000 through 1011_1111
-                return (@as(u16, code7) << 1) + @as(u16, try self.readF(u1, flag.buffered)) - 0b0011_0000;
-            } else if (code7 <= 0b1100_011) { // 8 bit, 280-287, codes 1100_0000 - 1100_0111
-                return (@as(u16, code7 - 0b1100000) << 1) + try self.readF(u1, flag.buffered) + 280;
-            } else { // 9 bit, 144-255, codes 1_1001_0000 - 1_1111_1111
-                return (@as(u16, code7 - 0b1100_100) << 2) + @as(u16, try self.readF(u2, flag.buffered | flag.reverse)) + 144;
-            }
-        }
-    };
-}
-
-test "readF" {
-    var fbs = std.io.fixedBufferStream(&[_]u8{ 0xf3, 0x48, 0xcd, 0xc9, 0x00, 0x00 });
-    var br = bitReader(u64, fbs.reader());
-    const F = BitReader64(@TypeOf(fbs.reader())).flag;
-
-    try testing.expectEqual(@as(u8, 48), br.nbits);
-    try testing.expectEqual(@as(u64, 0xc9cd48f3), br.bits);
-
-    try testing.expect(try br.readF(u1, 0) == 0b0000_0001);
-    try testing.expect(try br.readF(u2, 0) == 0b0000_0001);
-    try testing.expectEqual(@as(u8, 48 - 3), br.nbits);
-    try testing.expectEqual(@as(u3, 5), br.alignBits());
-
-    try testing.expect(try br.readF(u8, F.peek) == 0b0001_1110);
-    try testing.expect(try br.readF(u9, F.peek) == 0b1_0001_1110);
-    try br.shift(9);
-    try testing.expectEqual(@as(u8, 36), br.nbits);
-    try testing.expectEqual(@as(u3, 4), br.alignBits());
-
-    try testing.expect(try br.readF(u4, 0) == 0b0100);
-    try testing.expectEqual(@as(u8, 32), br.nbits);
-    try testing.expectEqual(@as(u3, 0), br.alignBits());
-
-    try br.shift(1);
-    try testing.expectEqual(@as(u3, 7), br.alignBits());
-    try br.shift(1);
-    try testing.expectEqual(@as(u3, 6), br.alignBits());
-    br.alignToByte();
-    try testing.expectEqual(@as(u3, 0), br.alignBits());
-
-    try testing.expectEqual(@as(u64, 0xc9), br.bits);
-    try testing.expectEqual(@as(u16, 0x9), try br.readN(4, 0));
-    try testing.expectEqual(@as(u16, 0xc), try br.readN(4, 0));
-}
-
-test "read block type 1 data" {
-    inline for ([_]type{ u64, u32 }) |T| {
-        const data = [_]u8{
-            0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, // deflate data block type 1
-            0x2f, 0xca, 0x49, 0xe1, 0x02, 0x00,
-            0x0c, 0x01, 0x02, 0x03, //
-            0xaa, 0xbb, 0xcc, 0xdd,
-        };
-        var fbs = std.io.fixedBufferStream(&data);
-        var br = bitReader(T, fbs.reader());
-        const F = BitReader(T, @TypeOf(fbs.reader())).flag;
-
-        try testing.expectEqual(@as(u1, 1), try br.readF(u1, 0)); // bfinal
-        try testing.expectEqual(@as(u2, 1), try br.readF(u2, 0)); // block_type
-
-        for ("Hello world\n") |c| {
-            try testing.expectEqual(@as(u8, c), try br.readF(u8, F.reverse) - 0x30);
-        }
-        try testing.expectEqual(@as(u7, 0), try br.readF(u7, 0)); // end of block
-        br.alignToByte();
-        try testing.expectEqual(@as(u32, 0x0302010c), try br.readF(u32, 0));
-        try testing.expectEqual(@as(u16, 0xbbaa), try br.readF(u16, 0));
-        try testing.expectEqual(@as(u16, 0xddcc), try br.readF(u16, 0));
-    }
-}
-
-test "shift/fill" {
-    const data = [_]u8{
-        0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-        0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-    };
-    var fbs = std.io.fixedBufferStream(&data);
-    var br = bitReader(u64, fbs.reader());
-
-    try testing.expectEqual(@as(u64, 0x08_07_06_05_04_03_02_01), br.bits);
-    try br.shift(8);
-    try testing.expectEqual(@as(u64, 0x00_08_07_06_05_04_03_02), br.bits);
-    try br.fill(60); // fill with 1 byte
-    try testing.expectEqual(@as(u64, 0x01_08_07_06_05_04_03_02), br.bits);
-    try br.shift(8 * 4 + 4);
-    try testing.expectEqual(@as(u64, 0x00_00_00_00_00_10_80_70), br.bits);
-
-    try br.fill(60); // fill with 4 bytes (shift by 4)
-    try testing.expectEqual(@as(u64, 0x00_50_40_30_20_10_80_70), br.bits);
-    try testing.expectEqual(@as(u8, 8 * 7 + 4), br.nbits);
-
-    try br.shift(@intCast(br.nbits)); // clear buffer
-    try br.fill(8); // refill with the rest of the bytes
-    try testing.expectEqual(@as(u64, 0x00_00_00_00_00_08_07_06), br.bits);
-}
-
-test "readAll" {
-    inline for ([_]type{ u64, u32 }) |T| {
-        const data = [_]u8{
-            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
-        };
-        var fbs = std.io.fixedBufferStream(&data);
-        var br = bitReader(T, fbs.reader());
-
-        switch (T) {
-            u64 => try testing.expectEqual(@as(u64, 0x08_07_06_05_04_03_02_01), br.bits),
-            u32 => try testing.expectEqual(@as(u32, 0x04_03_02_01), br.bits),
-            else => unreachable,
-        }
-
-        var out: [16]u8 = undefined;
-        try br.readAll(out[0..]);
-        try testing.expect(br.nbits == 0);
-        try testing.expect(br.bits == 0);
-
-        try testing.expectEqualSlices(u8, data[0..16], &out);
-    }
-}
-
-test "readFixedCode" {
-    inline for ([_]type{ u64, u32 }) |T| {
-        const fixed_codes = @import("huffman_encoder.zig").fixed_codes;
-
-        var fbs = std.io.fixedBufferStream(&fixed_codes);
-        var rdr = bitReader(T, fbs.reader());
-
-        for (0..286) |c| {
-            try testing.expectEqual(c, try rdr.readFixedCode());
-        }
-        try testing.expect(rdr.nbits == 0);
-    }
-}
-
-test "u32 leaves no bits on u32 reads" {
-    const data = [_]u8{
-        0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    };
-    var fbs = std.io.fixedBufferStream(&data);
-    var br = bitReader(u32, fbs.reader());
-
-    _ = try br.read(u3);
-    try testing.expectEqual(29, br.nbits);
-    br.alignToByte();
-    try testing.expectEqual(24, br.nbits);
-    try testing.expectEqual(0x04_03_02_01, try br.read(u32));
-    try testing.expectEqual(0, br.nbits);
-    try testing.expectEqual(0x08_07_06_05, try br.read(u32));
-    try testing.expectEqual(0, br.nbits);
-
-    _ = try br.read(u9);
-    try testing.expectEqual(23, br.nbits);
-    br.alignToByte();
-    try testing.expectEqual(16, br.nbits);
-    try testing.expectEqual(0x0e_0d_0c_0b, try br.read(u32));
-    try testing.expectEqual(0, br.nbits);
-}
-
-test "u64 need fill after alignToByte" {
-    const data = [_]u8{
-        0xff, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
-    };
-
-    // without fill
-    var fbs = std.io.fixedBufferStream(&data);
-    var br = bitReader(u64, fbs.reader());
-    _ = try br.read(u23);
-    try testing.expectEqual(41, br.nbits);
-    br.alignToByte();
-    try testing.expectEqual(40, br.nbits);
-    try testing.expectEqual(0x06_05_04_03, try br.read(u32));
-    try testing.expectEqual(8, br.nbits);
-    try testing.expectEqual(0x0a_09_08_07, try br.read(u32));
-    try testing.expectEqual(32, br.nbits);
-
-    // fill after align ensures all bits filled
-    fbs.reset();
-    br = bitReader(u64, fbs.reader());
-    _ = try br.read(u23);
-    try testing.expectEqual(41, br.nbits);
-    br.alignToByte();
-    try br.fill(0);
-    try testing.expectEqual(64, br.nbits);
-    try testing.expectEqual(0x06_05_04_03, try br.read(u32));
-    try testing.expectEqual(32, br.nbits);
-    try testing.expectEqual(0x0a_09_08_07, try br.read(u32));
-    try testing.expectEqual(0, br.nbits);
-}
diff --git a/lib/std/compress/flate/bit_writer.zig b/lib/std/compress/flate/bit_writer.zig
deleted file mode 100644
index b5d84c7e2a..0000000000
--- a/lib/std/compress/flate/bit_writer.zig
+++ /dev/null
@@ -1,99 +0,0 @@
-const std = @import("std");
-const assert = std.debug.assert;
-
-/// Bit writer for use in deflate (compression).
-///
-/// Has internal bits buffer of 64 bits and internal bytes buffer of 248 bytes.
-/// When we accumulate 48 bits 6 bytes are moved to the bytes buffer. When we
-/// accumulate 240 bytes they are flushed to the underlying inner_writer.
-///
-pub fn BitWriter(comptime WriterType: type) type {
-    // buffer_flush_size indicates the buffer size
-    // after which bytes are flushed to the writer.
-    // Should preferably be a multiple of 6, since
-    // we accumulate 6 bytes between writes to the buffer.
-    const buffer_flush_size = 240;
-
-    // buffer_size is the actual output byte buffer size.
-    // It must have additional headroom for a flush
-    // which can contain up to 8 bytes.
-    const buffer_size = buffer_flush_size + 8;
-
-    return struct {
-        inner_writer: WriterType,
-
-        // Data waiting to be written is bytes[0 .. nbytes]
-        // and then the low nbits of bits.  Data is always written
-        // sequentially into the bytes array.
-        bits: u64 = 0,
-        nbits: u32 = 0, // number of bits
-        bytes: [buffer_size]u8 = undefined,
-        nbytes: u32 = 0, // number of bytes
-
-        const Self = @This();
-
-        pub const Error = WriterType.Error || error{UnfinishedBits};
-
-        pub fn init(writer: WriterType) Self {
-            return .{ .inner_writer = writer };
-        }
-
-        pub fn setWriter(self: *Self, new_writer: WriterType) void {
-            //assert(self.bits == 0 and self.nbits == 0 and self.nbytes == 0);
-            self.inner_writer = new_writer;
-        }
-
-        pub fn flush(self: *Self) Error!void {
-            var n = self.nbytes;
-            while (self.nbits != 0) {
-                self.bytes[n] = @as(u8, @truncate(self.bits));
-                self.bits >>= 8;
-                if (self.nbits > 8) { // Avoid underflow
-                    self.nbits -= 8;
-                } else {
-                    self.nbits = 0;
-                }
-                n += 1;
-            }
-            self.bits = 0;
-            _ = try self.inner_writer.write(self.bytes[0..n]);
-            self.nbytes = 0;
-        }
-
-        pub fn writeBits(self: *Self, b: u32, nb: u32) Error!void {
-            self.bits |= @as(u64, @intCast(b)) << @as(u6, @intCast(self.nbits));
-            self.nbits += nb;
-            if (self.nbits < 48)
-                return;
-
-            var n = self.nbytes;
-            std.mem.writeInt(u64, self.bytes[n..][0..8], self.bits, .little);
-            n += 6;
-            if (n >= buffer_flush_size) {
-                _ = try self.inner_writer.write(self.bytes[0..n]);
-                n = 0;
-            }
-            self.nbytes = n;
-            self.bits >>= 48;
-            self.nbits -= 48;
-        }
-
-        pub fn writeBytes(self: *Self, bytes: []const u8) Error!void {
-            var n = self.nbytes;
-            if (self.nbits & 7 != 0) {
-                return error.UnfinishedBits;
-            }
-            while (self.nbits != 0) {
-                self.bytes[n] = @as(u8, @truncate(self.bits));
-                self.bits >>= 8;
-                self.nbits -= 8;
-                n += 1;
-            }
-            if (n != 0) {
-                _ = try self.inner_writer.write(self.bytes[0..n]);
-            }
-            self.nbytes = 0;
-            _ = try self.inner_writer.write(bytes);
-        }
-    };
-}
diff --git a/lib/std/compress/flate/block_writer.zig b/lib/std/compress/flate/block_writer.zig
deleted file mode 100644
index fa0d299e84..0000000000
--- a/lib/std/compress/flate/block_writer.zig
+++ /dev/null
@@ -1,706 +0,0 @@
-const std = @import("std");
-const io = std.io;
-const assert = std.debug.assert;
-
-const hc = @import("huffman_encoder.zig");
-const consts = @import("consts.zig").huffman;
-const Token = @import("Token.zig");
-const BitWriter = @import("bit_writer.zig").BitWriter;
-
-pub fn blockWriter(writer: anytype) BlockWriter(@TypeOf(writer)) {
-    return BlockWriter(@TypeOf(writer)).init(writer);
-}
-
-/// Accepts list of tokens, decides what is best block type to write. What block
-/// type will provide best compression. Writes header and body of the block.
-///
-pub fn BlockWriter(comptime WriterType: type) type {
-    const BitWriterType = BitWriter(WriterType);
-    return struct {
-        const codegen_order = consts.codegen_order;
-        const end_code_mark = 255;
-        const Self = @This();
-
-        pub const Error = BitWriterType.Error;
-        bit_writer: BitWriterType,
-
-        codegen_freq: [consts.codegen_code_count]u16 = undefined,
-        literal_freq: [consts.max_num_lit]u16 = undefined,
-        distance_freq: [consts.distance_code_count]u16 = undefined,
-        codegen: [consts.max_num_lit + consts.distance_code_count + 1]u8 = undefined,
-        literal_encoding: hc.LiteralEncoder = .{},
-        distance_encoding: hc.DistanceEncoder = .{},
-        codegen_encoding: hc.CodegenEncoder = .{},
-        fixed_literal_encoding: hc.LiteralEncoder,
-        fixed_distance_encoding: hc.DistanceEncoder,
-        huff_distance: hc.DistanceEncoder,
-
-        pub fn init(writer: WriterType) Self {
-            return .{
-                .bit_writer = BitWriterType.init(writer),
-                .fixed_literal_encoding = hc.fixedLiteralEncoder(),
-                .fixed_distance_encoding = hc.fixedDistanceEncoder(),
-                .huff_distance = hc.huffmanDistanceEncoder(),
-            };
-        }
-
-        /// Flush intrenal bit buffer to the writer.
-        /// Should be called only when bit stream is at byte boundary.
-        ///
-        /// That is after final block; when last byte could be incomplete or
-        /// after stored block; which is aligned to the byte boundary (it has x
-        /// padding bits after first 3 bits).
-        pub fn flush(self: *Self) Error!void {
-            try self.bit_writer.flush();
-        }
-
-        pub fn setWriter(self: *Self, new_writer: WriterType) void {
-            self.bit_writer.setWriter(new_writer);
-        }
-
-        fn writeCode(self: *Self, c: hc.HuffCode) Error!void {
-            try self.bit_writer.writeBits(c.code, c.len);
-        }
-
-        // RFC 1951 3.2.7 specifies a special run-length encoding for specifying
-        // the literal and distance lengths arrays (which are concatenated into a single
-        // array).  This method generates that run-length encoding.
-        //
-        // The result is written into the codegen array, and the frequencies
-        // of each code is written into the codegen_freq array.
-        // Codes 0-15 are single byte codes. Codes 16-18 are followed by additional
-        // information. Code bad_code is an end marker
-        //
-        // num_literals: The number of literals in literal_encoding
-        // num_distances: The number of distances in distance_encoding
-        // lit_enc: The literal encoder to use
-        // dist_enc: The distance encoder to use
-        fn generateCodegen(
-            self: *Self,
-            num_literals: u32,
-            num_distances: u32,
-            lit_enc: *hc.LiteralEncoder,
-            dist_enc: *hc.DistanceEncoder,
-        ) void {
-            for (self.codegen_freq, 0..) |_, i| {
-                self.codegen_freq[i] = 0;
-            }
-
-            // Note that we are using codegen both as a temporary variable for holding
-            // a copy of the frequencies, and as the place where we put the result.
-            // This is fine because the output is always shorter than the input used
-            // so far.
-            var codegen = &self.codegen; // cache
-            // Copy the concatenated code sizes to codegen. Put a marker at the end.
-            var cgnl = codegen[0..num_literals];
-            for (cgnl, 0..) |_, i| {
-                cgnl[i] = @as(u8, @intCast(lit_enc.codes[i].len));
-            }
-
-            cgnl = codegen[num_literals .. num_literals + num_distances];
-            for (cgnl, 0..) |_, i| {
-                cgnl[i] = @as(u8, @intCast(dist_enc.codes[i].len));
-            }
-            codegen[num_literals + num_distances] = end_code_mark;
-
-            var size = codegen[0];
-            var count: i32 = 1;
-            var out_index: u32 = 0;
-            var in_index: u32 = 1;
-            while (size != end_code_mark) : (in_index += 1) {
-                // INVARIANT: We have seen "count" copies of size that have not yet
-                // had output generated for them.
-                const next_size = codegen[in_index];
-                if (next_size == size) {
-                    count += 1;
-                    continue;
-                }
-                // We need to generate codegen indicating "count" of size.
-                if (size != 0) {
-                    codegen[out_index] = size;
-                    out_index += 1;
-                    self.codegen_freq[size] += 1;
-                    count -= 1;
-                    while (count >= 3) {
-                        var n: i32 = 6;
-                        if (n > count) {
-                            n = count;
-                        }
-                        codegen[out_index] = 16;
-                        out_index += 1;
-                        codegen[out_index] = @as(u8, @intCast(n - 3));
-                        out_index += 1;
-                        self.codegen_freq[16] += 1;
-                        count -= n;
-                    }
-                } else {
-                    while (count >= 11) {
-                        var n: i32 = 138;
-                        if (n > count) {
-                            n = count;
-                        }
-                        codegen[out_index] = 18;
-                        out_index += 1;
-                        codegen[out_index] = @as(u8, @intCast(n - 11));
-                        out_index += 1;
-                        self.codegen_freq[18] += 1;
-                        count -= n;
-                    }
-                    if (count >= 3) {
-                        // 3 <= count <= 10
-                        codegen[out_index] = 17;
-                        out_index += 1;
-                        codegen[out_index] = @as(u8, @intCast(count - 3));
-                        out_index += 1;
-                        self.codegen_freq[17] += 1;
-                        count = 0;
-                    }
-                }
-                count -= 1;
-                while (count >= 0) : (count -= 1) {
-                    codegen[out_index] = size;
-                    out_index += 1;
-                    self.codegen_freq[size] += 1;
-                }
-                // Set up invariant for next time through the loop.
-                size = next_size;
-                count = 1;
-            }
-            // Marker indicating the end of the codegen.
-            codegen[out_index] = end_code_mark;
-        }
-
-        const DynamicSize = struct {
-            size: u32,
-            num_codegens: u32,
-        };
-
-        // dynamicSize returns the size of dynamically encoded data in bits.
-        fn dynamicSize(
-            self: *Self,
-            lit_enc: *hc.LiteralEncoder, // literal encoder
-            dist_enc: *hc.DistanceEncoder, // distance encoder
-            extra_bits: u32,
-        ) DynamicSize {
-            var num_codegens = self.codegen_freq.len;
-            while (num_codegens > 4 and self.codegen_freq[codegen_order[num_codegens - 1]] == 0) {
-                num_codegens -= 1;
-            }
-            const header = 3 + 5 + 5 + 4 + (3 * num_codegens) +
-                self.codegen_encoding.bitLength(self.codegen_freq[0..]) +
-                self.codegen_freq[16] * 2 +
-                self.codegen_freq[17] * 3 +
-                self.codegen_freq[18] * 7;
-            const size = header +
-                lit_enc.bitLength(&self.literal_freq) +
-                dist_enc.bitLength(&self.distance_freq) +
-                extra_bits;
-
-            return DynamicSize{
-                .size = @as(u32, @intCast(size)),
-                .num_codegens = @as(u32, @intCast(num_codegens)),
-            };
-        }
-
-        // fixedSize returns the size of dynamically encoded data in bits.
-        fn fixedSize(self: *Self, extra_bits: u32) u32 {
-            return 3 +
-                self.fixed_literal_encoding.bitLength(&self.literal_freq) +
-                self.fixed_distance_encoding.bitLength(&self.distance_freq) +
-                extra_bits;
-        }
-
-        const StoredSize = struct {
-            size: u32,
-            storable: bool,
-        };
-
-        // storedSizeFits calculates the stored size, including header.
-        // The function returns the size in bits and whether the block
-        // fits inside a single block.
-        fn storedSizeFits(in: ?[]const u8) StoredSize {
-            if (in == null) {
-                return .{ .size = 0, .storable = false };
-            }
-            if (in.?.len <= consts.max_store_block_size) {
-                return .{ .size = @as(u32, @intCast((in.?.len + 5) * 8)), .storable = true };
-            }
-            return .{ .size = 0, .storable = false };
-        }
-
-        // Write the header of a dynamic Huffman block to the output stream.
-        //
-        //  num_literals: The number of literals specified in codegen
-        //  num_distances: The number of distances specified in codegen
-        //  num_codegens: The number of codegens used in codegen
-        //  eof: Is it the end-of-file? (end of stream)
-        fn dynamicHeader(
-            self: *Self,
-            num_literals: u32,
-            num_distances: u32,
-            num_codegens: u32,
-            eof: bool,
-        ) Error!void {
-            const first_bits: u32 = if (eof) 5 else 4;
-            try self.bit_writer.writeBits(first_bits, 3);
-            try self.bit_writer.writeBits(num_literals - 257, 5);
-            try self.bit_writer.writeBits(num_distances - 1, 5);
-            try self.bit_writer.writeBits(num_codegens - 4, 4);
-
-            var i: u32 = 0;
-            while (i < num_codegens) : (i += 1) {
-                const value = self.codegen_encoding.codes[codegen_order[i]].len;
-                try self.bit_writer.writeBits(value, 3);
-            }
-
-            i = 0;
-            while (true) {
-                const code_word: u32 = @as(u32, @intCast(self.codegen[i]));
-                i += 1;
-                if (code_word == end_code_mark) {
-                    break;
-                }
-                try self.writeCode(self.codegen_encoding.codes[@as(u32, @intCast(code_word))]);
-
-                switch (code_word) {
-                    16 => {
-                        try self.bit_writer.writeBits(self.codegen[i], 2);
-                        i += 1;
-                    },
-                    17 => {
-                        try self.bit_writer.writeBits(self.codegen[i], 3);
-                        i += 1;
-                    },
-                    18 => {
-                        try self.bit_writer.writeBits(self.codegen[i], 7);
-                        i += 1;
-                    },
-                    else => {},
-                }
-            }
-        }
-
-        fn storedHeader(self: *Self, length: usize, eof: bool) Error!void {
-            assert(length <= 65535);
-            const flag: u32 = if (eof) 1 else 0;
-            try self.bit_writer.writeBits(flag, 3);
-            try self.flush();
-            const l: u16 = @intCast(length);
-            try self.bit_writer.writeBits(l, 16);
-            try self.bit_writer.writeBits(~l, 16);
-        }
-
-        fn fixedHeader(self: *Self, eof: bool) Error!void {
-            // Indicate that we are a fixed Huffman block
-            var value: u32 = 2;
-            if (eof) {
-                value = 3;
-            }
-            try self.bit_writer.writeBits(value, 3);
-        }
-
-        // Write a block of tokens with the smallest encoding. Will choose block type.
-        // The original input can be supplied, and if the huffman encoded data
-        // is larger than the original bytes, the data will be written as a
-        // stored block.
-        // If the input is null, the tokens will always be Huffman encoded.
-        pub fn write(self: *Self, tokens: []const Token, eof: bool, input: ?[]const u8) Error!void {
-            const lit_and_dist = self.indexTokens(tokens);
-            const num_literals = lit_and_dist.num_literals;
-            const num_distances = lit_and_dist.num_distances;
-
-            var extra_bits: u32 = 0;
-            const ret = storedSizeFits(input);
-            const stored_size = ret.size;
-            const storable = ret.storable;
-
-            if (storable) {
-                // We only bother calculating the costs of the extra bits required by
-                // the length of distance fields (which will be the same for both fixed
-                // and dynamic encoding), if we need to compare those two encodings
-                // against stored encoding.
-                var length_code: u16 = Token.length_codes_start + 8;
-                while (length_code < num_literals) : (length_code += 1) {
-                    // First eight length codes have extra size = 0.
-                    extra_bits += @as(u32, @intCast(self.literal_freq[length_code])) *
-                        @as(u32, @intCast(Token.lengthExtraBits(length_code)));
-                }
-                var distance_code: u16 = 4;
-                while (distance_code < num_distances) : (distance_code += 1) {
-                    // First four distance codes have extra size = 0.
-                    extra_bits += @as(u32, @intCast(self.distance_freq[distance_code])) *
-                        @as(u32, @intCast(Token.distanceExtraBits(distance_code)));
-                }
-            }
-
-            // Figure out smallest code.
-            // Fixed Huffman baseline.
-            var literal_encoding = &self.fixed_literal_encoding;
-            var distance_encoding = &self.fixed_distance_encoding;
-            var size = self.fixedSize(extra_bits);
-
-            // Dynamic Huffman?
-            var num_codegens: u32 = 0;
-
-            // Generate codegen and codegenFrequencies, which indicates how to encode
-            // the literal_encoding and the distance_encoding.
-            self.generateCodegen(
-                num_literals,
-                num_distances,
-                &self.literal_encoding,
-                &self.distance_encoding,
-            );
-            self.codegen_encoding.generate(self.codegen_freq[0..], 7);
-            const dynamic_size = self.dynamicSize(
-                &self.literal_encoding,
-                &self.distance_encoding,
-                extra_bits,
-            );
-            const dyn_size = dynamic_size.size;
-            num_codegens = dynamic_size.num_codegens;
-
-            if (dyn_size < size) {
-                size = dyn_size;
-                literal_encoding = &self.literal_encoding;
-                distance_encoding = &self.distance_encoding;
-            }
-
-            // Stored bytes?
-            if (storable and stored_size < size) {
-                try self.storedBlock(input.?, eof);
-                return;
-            }
-
-            // Huffman.
-            if (@intFromPtr(literal_encoding) == @intFromPtr(&self.fixed_literal_encoding)) {
-                try self.fixedHeader(eof);
-            } else {
-                try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
-            }
-
-            // Write the tokens.
-            try self.writeTokens(tokens, &literal_encoding.codes, &distance_encoding.codes);
-        }
-
-        pub fn storedBlock(self: *Self, input: []const u8, eof: bool) Error!void {
-            try self.storedHeader(input.len, eof);
-            try self.bit_writer.writeBytes(input);
-        }
-
-        // writeBlockDynamic encodes a block using a dynamic Huffman table.
-        // This should be used if the symbols used have a disproportionate
-        // histogram distribution.
-        // If input is supplied and the compression savings are below 1/16th of the
-        // input size the block is stored.
-        fn dynamicBlock(
-            self: *Self,
-            tokens: []const Token,
-            eof: bool,
-            input: ?[]const u8,
-        ) Error!void {
-            const total_tokens = self.indexTokens(tokens);
-            const num_literals = total_tokens.num_literals;
-            const num_distances = total_tokens.num_distances;
-
-            // Generate codegen and codegenFrequencies, which indicates how to encode
-            // the literal_encoding and the distance_encoding.
-            self.generateCodegen(
-                num_literals,
-                num_distances,
-                &self.literal_encoding,
-                &self.distance_encoding,
-            );
-            self.codegen_encoding.generate(self.codegen_freq[0..], 7);
-            const dynamic_size = self.dynamicSize(&self.literal_encoding, &self.distance_encoding, 0);
-            const size = dynamic_size.size;
-            const num_codegens = dynamic_size.num_codegens;
-
-            // Store bytes, if we don't get a reasonable improvement.
-
-            const stored_size = storedSizeFits(input);
-            const ssize = stored_size.size;
-            const storable = stored_size.storable;
-            if (storable and ssize < (size + (size >> 4))) {
-                try self.storedBlock(input.?, eof);
-                return;
-            }
-
-            // Write Huffman table.
-            try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
-
-            // Write the tokens.
-            try self.writeTokens(tokens, &self.literal_encoding.codes, &self.distance_encoding.codes);
-        }
-
-        const TotalIndexedTokens = struct {
-            num_literals: u32,
-            num_distances: u32,
-        };
-
-        // Indexes a slice of tokens followed by an end_block_marker, and updates
-        // literal_freq and distance_freq, and generates literal_encoding
-        // and distance_encoding.
-        // The number of literal and distance tokens is returned.
-        fn indexTokens(self: *Self, tokens: []const Token) TotalIndexedTokens {
-            var num_literals: u32 = 0;
-            var num_distances: u32 = 0;
-
-            for (self.literal_freq, 0..) |_, i| {
-                self.literal_freq[i] = 0;
-            }
-            for (self.distance_freq, 0..) |_, i| {
-                self.distance_freq[i] = 0;
-            }
-
-            for (tokens) |t| {
-                if (t.kind == Token.Kind.literal) {
-                    self.literal_freq[t.literal()] += 1;
-                    continue;
-                }
-                self.literal_freq[t.lengthCode()] += 1;
-                self.distance_freq[t.distanceCode()] += 1;
-            }
-            // add end_block_marker token at the end
-            self.literal_freq[consts.end_block_marker] += 1;
-
-            // get the number of literals
-            num_literals = @as(u32, @intCast(self.literal_freq.len));
-            while (self.literal_freq[num_literals - 1] == 0) {
-                num_literals -= 1;
-            }
-            // get the number of distances
-            num_distances = @as(u32, @intCast(self.distance_freq.len));
-            while (num_distances > 0 and self.distance_freq[num_distances - 1] == 0) {
-                num_distances -= 1;
-            }
-            if (num_distances == 0) {
-                // We haven't found a single match. If we want to go with the dynamic encoding,
-                // we should count at least one distance to be sure that the distance huffman tree could be encoded.
-                self.distance_freq[0] = 1;
-                num_distances = 1;
-            }
-            self.literal_encoding.generate(&self.literal_freq, 15);
-            self.distance_encoding.generate(&self.distance_freq, 15);
-            return TotalIndexedTokens{
-                .num_literals = num_literals,
-                .num_distances = num_distances,
-            };
-        }
-
-        // Writes a slice of tokens to the output followed by and end_block_marker.
-        // codes for literal and distance encoding must be supplied.
-        fn writeTokens(
-            self: *Self,
-            tokens: []const Token,
-            le_codes: []hc.HuffCode,
-            oe_codes: []hc.HuffCode,
-        ) Error!void {
-            for (tokens) |t| {
-                if (t.kind == Token.Kind.literal) {
-                    try self.writeCode(le_codes[t.literal()]);
-                    continue;
-                }
-
-                // Write the length
-                const le = t.lengthEncoding();
-                try self.writeCode(le_codes[le.code]);
-                if (le.extra_bits > 0) {
-                    try self.bit_writer.writeBits(le.extra_length, le.extra_bits);
-                }
-
-                // Write the distance
-                const oe = t.distanceEncoding();
-                try self.writeCode(oe_codes[oe.code]);
-                if (oe.extra_bits > 0) {
-                    try self.bit_writer.writeBits(oe.extra_distance, oe.extra_bits);
-                }
-            }
-            // add end_block_marker at the end
-            try self.writeCode(le_codes[consts.end_block_marker]);
-        }
-
-        // Encodes a block of bytes as either Huffman encoded literals or uncompressed bytes
-        // if the results only gains very little from compression.
-        pub fn huffmanBlock(self: *Self, input: []const u8, eof: bool) Error!void {
-            // Add everything as literals
-            histogram(input, &self.literal_freq);
-
-            self.literal_freq[consts.end_block_marker] = 1;
-
-            const num_literals = consts.end_block_marker + 1;
-            self.distance_freq[0] = 1;
-            const num_distances = 1;
-
-            self.literal_encoding.generate(&self.literal_freq, 15);
-
-            // Figure out smallest code.
-            // Always use dynamic Huffman or Store
-            var num_codegens: u32 = 0;
-
-            // Generate codegen and codegenFrequencies, which indicates how to encode
-            // the literal_encoding and the distance_encoding.
-            self.generateCodegen(
-                num_literals,
-                num_distances,
-                &self.literal_encoding,
-                &self.huff_distance,
-            );
-            self.codegen_encoding.generate(self.codegen_freq[0..], 7);
-            const dynamic_size = self.dynamicSize(&self.literal_encoding, &self.huff_distance, 0);
-            const size = dynamic_size.size;
-            num_codegens = dynamic_size.num_codegens;
-
-            // Store bytes, if we don't get a reasonable improvement.
-            const stored_size_ret = storedSizeFits(input);
-            const ssize = stored_size_ret.size;
-            const storable = stored_size_ret.storable;
-
-            if (storable and ssize < (size + (size >> 4))) {
-                try self.storedBlock(input, eof);
-                return;
-            }
-
-            // Huffman.
-            try self.dynamicHeader(num_literals, num_distances, num_codegens, eof);
-            const encoding = self.literal_encoding.codes[0..257];
-
-            for (input) |t| {
-                const c = encoding[t];
-                try self.bit_writer.writeBits(c.code, c.len);
-            }
-            try self.writeCode(encoding[consts.end_block_marker]);
-        }
-
-        // histogram accumulates a histogram of b in h.
-        fn histogram(b: []const u8, h: *[286]u16) void {
-            // Clear histogram
-            for (h, 0..) |_, i| {
-                h[i] = 0;
-            }
-
-            var lh = h.*[0..256];
-            for (b) |t| {
-                lh[t] += 1;
-            }
-        }
-    };
-}
-
-// tests
-const expect = std.testing.expect;
-const fmt = std.fmt;
-const testing = std.testing;
-const ArrayList = std.ArrayList;
-
-const TestCase = @import("testdata/block_writer.zig").TestCase;
-const testCases = @import("testdata/block_writer.zig").testCases;
-
-// tests if the writeBlock encoding has changed.
-test "write" {
-    inline for (0..testCases.len) |i| {
-        try testBlock(testCases[i], .write_block);
-    }
-}
-
-// tests if the writeBlockDynamic encoding has changed.
-test "dynamicBlock" {
-    inline for (0..testCases.len) |i| {
-        try testBlock(testCases[i], .write_dyn_block);
-    }
-}
-
-test "huffmanBlock" {
-    inline for (0..testCases.len) |i| {
-        try testBlock(testCases[i], .write_huffman_block);
-    }
-    try testBlock(.{
-        .tokens = &[_]Token{},
-        .input = "huffman-rand-max.input",
-        .want = "huffman-rand-max.{s}.expect",
-    }, .write_huffman_block);
-}
-
-const TestFn = enum {
-    write_block,
-    write_dyn_block, // write dynamic block
-    write_huffman_block,
-
-    fn to_s(self: TestFn) []const u8 {
-        return switch (self) {
-            .write_block => "wb",
-            .write_dyn_block => "dyn",
-            .write_huffman_block => "huff",
-        };
-    }
-
-    fn write(
-        comptime self: TestFn,
-        bw: anytype,
-        tok: []const Token,
-        input: ?[]const u8,
-        final: bool,
-    ) !void {
-        switch (self) {
-            .write_block => try bw.write(tok, final, input),
-            .write_dyn_block => try bw.dynamicBlock(tok, final, input),
-            .write_huffman_block => try bw.huffmanBlock(input.?, final),
-        }
-        try bw.flush();
-    }
-};
-
-// testBlock tests a block against its references
-//
-// size
-//  64K [file-name].input                  - input non compressed file
-// 8.1K [file-name].golden                 -
-//   78 [file-name].dyn.expect             - output with writeBlockDynamic
-//   78 [file-name].wb.expect              - output with writeBlock
-// 8.1K [file-name].huff.expect            - output with writeBlockHuff
-//   78 [file-name].dyn.expect-noinput     - output with writeBlockDynamic when input is null
-//   78 [file-name].wb.expect-noinput      - output with writeBlock when input is null
-//
-//   wb   - writeBlock
-//   dyn  - writeBlockDynamic
-//   huff - writeBlockHuff
-//
-fn testBlock(comptime tc: TestCase, comptime tfn: TestFn) !void {
-    if (tc.input.len != 0 and tc.want.len != 0) {
-        const want_name = comptime fmt.comptimePrint(tc.want, .{tfn.to_s()});
-        const input = @embedFile("testdata/block_writer/" ++ tc.input);
-        const want = @embedFile("testdata/block_writer/" ++ want_name);
-        try testWriteBlock(tfn, input, want, tc.tokens);
-    }
-
-    if (tfn == .write_huffman_block) {
-        return;
-    }
-
-    const want_name_no_input = comptime fmt.comptimePrint(tc.want_no_input, .{tfn.to_s()});
-    const want = @embedFile("testdata/block_writer/" ++ want_name_no_input);
-    try testWriteBlock(tfn, null, want, tc.tokens);
-}
-
-// Uses writer function `tfn` to write `tokens`, tests that we got `want` as output.
-fn testWriteBlock(comptime tfn: TestFn, input: ?[]const u8, want: []const u8, tokens: []const Token) !void {
-    var buf = ArrayList(u8).init(testing.allocator);
-    var bw = blockWriter(buf.writer());
-    try tfn.write(&bw, tokens, input, false);
-    var got = buf.items;
-    try testing.expectEqualSlices(u8, want, got); // expect writeBlock to yield expected result
-    try expect(got[0] & 0b0000_0001 == 0); // bfinal is not set
-    //
-    // Test if the writer produces the same output after reset.
-    buf.deinit();
-    buf = ArrayList(u8).init(testing.allocator);
-    defer buf.deinit();
-    bw.setWriter(buf.writer());
-
-    try tfn.write(&bw, tokens, input, true);
-    try bw.flush();
-    got = buf.items;
-
-    try expect(got[0] & 1 == 1); // bfinal is set
-    buf.items[0] &= 0b1111_1110; // remove bfinal bit, so we can run test slices
-    try testing.expectEqualSlices(u8, want, got); // expect writeBlock to yield expected result
-}
diff --git a/lib/std/compress/flate/consts.zig b/lib/std/compress/flate/consts.zig
deleted file mode 100644
index b17083461b..0000000000
--- a/lib/std/compress/flate/consts.zig
+++ /dev/null
@@ -1,49 +0,0 @@
-pub const deflate = struct {
-    // Number of tokens to accumulate in deflate before starting block encoding.
-    //
-    // In zlib this depends on memlevel: 6 + memlevel, where default memlevel is
-    // 8 and max 9 that gives 14 or 15 bits.
-    pub const tokens = 1 << 15;
-};
-
-pub const match = struct {
-    pub const base_length = 3; // smallest match length per the RFC section 3.2.5
-    pub const min_length = 4; // min length used in this algorithm
-    pub const max_length = 258;
-
-    pub const min_distance = 1;
-    pub const max_distance = 32768;
-};
-
-pub const history = struct {
-    pub const len = match.max_distance;
-};
-
-pub const lookup = struct {
-    pub const bits = 15;
-    pub const len = 1 << bits;
-    pub const shift = 32 - bits;
-};
-
-pub const huffman = struct {
-    // The odd order in which the codegen code sizes are written.
-    pub const codegen_order = [_]u32{ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
-    // The number of codegen codes.
-    pub const codegen_code_count = 19;
-
-    // The largest distance code.
-    pub const distance_code_count = 30;
-
-    // Maximum number of literals.
-    pub const max_num_lit = 286;
-
-    // Max number of frequencies used for a Huffman Code
-    // Possible lengths are codegen_code_count (19), distance_code_count (30) and max_num_lit (286).
-    // The largest of these is max_num_lit.
-    pub const max_num_frequencies = max_num_lit;
-
-    // Biggest block size for uncompressed block.
-    pub const max_store_block_size = 65535;
-    // The special code used to mark the end of a block.
-    pub const end_block_marker = 256;
-};
diff --git a/lib/std/compress/flate/container.zig b/lib/std/compress/flate/container.zig
deleted file mode 100644
index fe6dec446d..0000000000
--- a/lib/std/compress/flate/container.zig
+++ /dev/null
@@ -1,208 +0,0 @@
-//! Container of the deflate bit stream body. Container adds header before
-//! deflate bit stream and footer after. It can bi gzip, zlib or raw (no header,
-//! no footer, raw bit stream).
-//!
-//! Zlib format is defined in rfc 1950. Header has 2 bytes and footer 4 bytes
-//! addler 32 checksum.
-//!
-//! Gzip format is defined in rfc 1952. Header has 10+ bytes and footer 4 bytes
-//! crc32 checksum and 4 bytes of uncompressed data length.
-//!
-//!
-//! rfc 1950: https://datatracker.ietf.org/doc/html/rfc1950#page-4
-//! rfc 1952: https://datatracker.ietf.org/doc/html/rfc1952#page-5
-//!
-
-const std = @import("std");
-
-pub const Container = enum {
-    raw, // no header or footer
-    gzip, // gzip header and footer
-    zlib, // zlib header and footer
-
-    pub fn size(w: Container) usize {
-        return headerSize(w) + footerSize(w);
-    }
-
-    pub fn headerSize(w: Container) usize {
-        return switch (w) {
-            .gzip => 10,
-            .zlib => 2,
-            .raw => 0,
-        };
-    }
-
-    pub fn footerSize(w: Container) usize {
-        return switch (w) {
-            .gzip => 8,
-            .zlib => 4,
-            .raw => 0,
-        };
-    }
-
-    pub const list = [_]Container{ .raw, .gzip, .zlib };
-
-    pub const Error = error{
-        BadGzipHeader,
-        BadZlibHeader,
-        WrongGzipChecksum,
-        WrongGzipSize,
-        WrongZlibChecksum,
-    };
-
-    pub fn writeHeader(comptime wrap: Container, writer: anytype) !void {
-        switch (wrap) {
-            .gzip => {
-                // GZIP 10 byte header (https://datatracker.ietf.org/doc/html/rfc1952#page-5):
-                //  - ID1 (IDentification 1), always 0x1f
-                //  - ID2 (IDentification 2), always 0x8b
-                //  - CM (Compression Method), always 8 = deflate
-                //  - FLG (Flags), all set to 0
-                //  - 4 bytes, MTIME (Modification time), not used, all set to zero
-                //  - XFL (eXtra FLags), all set to zero
-                //  - OS (Operating System), 03 = Unix
-                const gzipHeader = [_]u8{ 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03 };
-                try writer.writeAll(&gzipHeader);
-            },
-            .zlib => {
-                // ZLIB has a two-byte header (https://datatracker.ietf.org/doc/html/rfc1950#page-4):
-                // 1st byte:
-                //  - First four bits is the CINFO (compression info), which is 7 for the default deflate window size.
-                //  - The next four bits is the CM (compression method), which is 8 for deflate.
-                // 2nd byte:
-                //  - Two bits is the FLEVEL (compression level). Values are: 0=fastest, 1=fast, 2=default, 3=best.
-                //  - The next bit, FDICT, is set if a dictionary is given.
-                //  - The final five FCHECK bits form a mod-31 checksum.
-                //
-                // CINFO = 7, CM = 8, FLEVEL = 0b10, FDICT = 0, FCHECK = 0b11100
-                const zlibHeader = [_]u8{ 0x78, 0b10_0_11100 };
-                try writer.writeAll(&zlibHeader);
-            },
-            .raw => {},
-        }
-    }
-
-    pub fn writeFooter(comptime wrap: Container, hasher: *Hasher(wrap), writer: anytype) !void {
-        var bits: [4]u8 = undefined;
-        switch (wrap) {
-            .gzip => {
-                // GZIP 8 bytes footer
-                //  - 4 bytes, CRC32 (CRC-32)
-                //  - 4 bytes, ISIZE (Input SIZE) - size of the original (uncompressed) input data modulo 2^32
-                std.mem.writeInt(u32, &bits, hasher.chksum(), .little);
-                try writer.writeAll(&bits);
-
-                std.mem.writeInt(u32, &bits, hasher.bytesRead(), .little);
-                try writer.writeAll(&bits);
-            },
-            .zlib => {
-                // ZLIB (RFC 1950) is big-endian, unlike GZIP (RFC 1952).
-                // 4 bytes of ADLER32 (Adler-32 checksum)
-                // Checksum value of the uncompressed data (excluding any
-                // dictionary data) computed according to Adler-32
-                // algorithm.
-                std.mem.writeInt(u32, &bits, hasher.chksum(), .big);
-                try writer.writeAll(&bits);
-            },
-            .raw => {},
-        }
-    }
-
-    pub fn parseHeader(comptime wrap: Container, reader: anytype) !void {
-        switch (wrap) {
-            .gzip => try parseGzipHeader(reader),
-            .zlib => try parseZlibHeader(reader),
-            .raw => {},
-        }
-    }
-
-    fn parseGzipHeader(reader: anytype) !void {
-        const magic1 = try reader.read(u8);
-        const magic2 = try reader.read(u8);
-        const method = try reader.read(u8);
-        const flags = try reader.read(u8);
-        try reader.skipBytes(6); // mtime(4), xflags, os
-        if (magic1 != 0x1f or magic2 != 0x8b or method != 0x08)
-            return error.BadGzipHeader;
-        // Flags description: https://www.rfc-editor.org/rfc/rfc1952.html#page-5
-        if (flags != 0) {
-            if (flags & 0b0000_0100 != 0) { // FEXTRA
-                const extra_len = try reader.read(u16);
-                try reader.skipBytes(extra_len);
-            }
-            if (flags & 0b0000_1000 != 0) { // FNAME
-                try reader.skipStringZ();
-            }
-            if (flags & 0b0001_0000 != 0) { // FCOMMENT
-                try reader.skipStringZ();
-            }
-            if (flags & 0b0000_0010 != 0) { // FHCRC
-                try reader.skipBytes(2);
-            }
-        }
-    }
-
-    fn parseZlibHeader(reader: anytype) !void {
-        const cm = try reader.read(u4);
-        const cinfo = try reader.read(u4);
-        _ = try reader.read(u8);
-        if (cm != 8 or cinfo > 7) {
-            return error.BadZlibHeader;
-        }
-    }
-
-    pub fn parseFooter(comptime wrap: Container, hasher: *Hasher(wrap), reader: anytype) !void {
-        switch (wrap) {
-            .gzip => {
-                try reader.fill(0);
-                if (try reader.read(u32) != hasher.chksum()) return error.WrongGzipChecksum;
-                if (try reader.read(u32) != hasher.bytesRead()) return error.WrongGzipSize;
-            },
-            .zlib => {
-                const chksum: u32 = @byteSwap(hasher.chksum());
-                if (try reader.read(u32) != chksum) return error.WrongZlibChecksum;
-            },
-            .raw => {},
-        }
-    }
-
-    pub fn Hasher(comptime wrap: Container) type {
-        const HasherType = switch (wrap) {
-            .gzip => std.hash.Crc32,
-            .zlib => std.hash.Adler32,
-            .raw => struct {
-                pub fn init() @This() {
-                    return .{};
-                }
-            },
-        };
-
-        return struct {
-            hasher: HasherType = HasherType.init(),
-            bytes: usize = 0,
-
-            const Self = @This();
-
-            pub fn update(self: *Self, buf: []const u8) void {
-                switch (wrap) {
-                    .raw => {},
-                    else => {
-                        self.hasher.update(buf);
-                        self.bytes += buf.len;
-                    },
-                }
-            }
-
-            pub fn chksum(self: *Self) u32 {
-                switch (wrap) {
-                    .raw => return 0,
-                    else => return self.hasher.final(),
-                }
-            }
-
-            pub fn bytesRead(self: *Self) u32 {
-                return @truncate(self.bytes);
-            }
-        };
-    }
-};
diff --git a/lib/std/compress/flate/deflate.zig b/lib/std/compress/flate/deflate.zig
deleted file mode 100644
index fd93236000..0000000000
--- a/lib/std/compress/flate/deflate.zig
+++ /dev/null
@@ -1,744 +0,0 @@
-const std = @import("std");
-const io = std.io;
-const assert = std.debug.assert;
-const testing = std.testing;
-const expect = testing.expect;
-const print = std.debug.print;
-
-const Token = @import("Token.zig");
-const consts = @import("consts.zig");
-const BlockWriter = @import("block_writer.zig").BlockWriter;
-const Container = @import("container.zig").Container;
-const SlidingWindow = @import("SlidingWindow.zig");
-const Lookup = @import("Lookup.zig");
-
-pub const Options = struct {
-    level: Level = .default,
-};
-
-/// Trades between speed and compression size.
-/// Starts with level 4: in [zlib](https://github.com/madler/zlib/blob/abd3d1a28930f89375d4b41408b39f6c1be157b2/deflate.c#L115C1-L117C43)
-/// levels 1-3 are using different algorithm to perform faster but with less
-/// compression. That is not implemented here.
-pub const Level = enum(u4) {
-    // zig fmt: off
-    fast = 0xb,         level_4 = 4,
-                        level_5 = 5,
-    default = 0xc,      level_6 = 6,
-                        level_7 = 7,
-                        level_8 = 8,
-    best = 0xd,         level_9 = 9,
-    // zig fmt: on
-};
-
-/// Algorithm knobs for each level.
-const LevelArgs = struct {
-    good: u16, // Do less lookups if we already have match of this length.
-    nice: u16, // Stop looking for better match if we found match with at least this length.
-    lazy: u16, // Don't do lazy match find if got match with at least this length.
-    chain: u16, // How many lookups for previous match to perform.
-
-    pub fn get(level: Level) LevelArgs {
-        // zig fmt: off
-        return switch (level) {
-            .fast,    .level_4 => .{ .good =  4, .lazy =   4, .nice =  16, .chain =   16 },
-                      .level_5 => .{ .good =  8, .lazy =  16, .nice =  32, .chain =   32 },
-            .default, .level_6 => .{ .good =  8, .lazy =  16, .nice = 128, .chain =  128 },
-                      .level_7 => .{ .good =  8, .lazy =  32, .nice = 128, .chain =  256 },
-                      .level_8 => .{ .good = 32, .lazy = 128, .nice = 258, .chain = 1024 },
-            .best,    .level_9 => .{ .good = 32, .lazy = 258, .nice = 258, .chain = 4096 },
-        };
-        // zig fmt: on
-    }
-};
-
-/// Compress plain data from reader into compressed stream written to writer.
-pub fn compress(comptime container: Container, reader: anytype, writer: anytype, options: Options) !void {
-    var c = try compressor(container, writer, options);
-    try c.compress(reader);
-    try c.finish();
-}
-
-/// Create compressor for writer type.
-pub fn compressor(comptime container: Container, writer: anytype, options: Options) !Compressor(
-    container,
-    @TypeOf(writer),
-) {
-    return try Compressor(container, @TypeOf(writer)).init(writer, options);
-}
-
-/// Compressor type.
-pub fn Compressor(comptime container: Container, comptime WriterType: type) type {
-    const TokenWriterType = BlockWriter(WriterType);
-    return Deflate(container, WriterType, TokenWriterType);
-}
-
-/// Default compression algorithm. Has two steps: tokenization and token
-/// encoding.
-///
-/// Tokenization takes uncompressed input stream and produces list of tokens.
-/// Each token can be literal (byte of data) or match (backrefernce to previous
-/// data with length and distance). Tokenization accumulators 32K tokens, when
-/// full or `flush` is called tokens are passed to the `block_writer`. Level
-/// defines how hard (how slow) it tries to find match.
-///
-/// Block writer will decide which type of deflate block to write (stored, fixed,
-/// dynamic) and encode tokens to the output byte stream. Client has to call
-/// `finish` to write block with the final bit set.
-///
-/// Container defines type of header and footer which can be gzip, zlib or raw.
-/// They all share same deflate body. Raw has no header or footer just deflate
-/// body.
-///
-/// Compression algorithm explained in rfc-1951 (slightly edited for this case):
-///
-///   The compressor uses a chained hash table `lookup` to find duplicated
-///   strings, using a hash function that operates on 4-byte sequences. At any
-///   given point during compression, let XYZW be the next 4 input bytes
-///   (lookahead) to be examined (not necessarily all different, of course).
-///   First, the compressor examines the hash chain for XYZW. If the chain is
-///   empty, the compressor simply writes out X as a literal byte and advances
-///   one byte in the input. If the hash chain is not empty, indicating that the
-///   sequence XYZW (or, if we are unlucky, some other 4 bytes with the same
-///   hash function value) has occurred recently, the compressor compares all
-///   strings on the XYZW hash chain with the actual input data sequence
-///   starting at the current point, and selects the longest match.
-///
-///   To improve overall compression, the compressor defers the selection of
-///   matches ("lazy matching"): after a match of length N has been found, the
-///   compressor searches for a longer match starting at the next input byte. If
-///   it finds a longer match, it truncates the previous match to a length of
-///   one (thus producing a single literal byte) and then emits the longer
-///   match. Otherwise, it emits the original match, and, as described above,
-///   advances N bytes before continuing.
-///
-///
-/// Allocates statically ~400K (192K lookup, 128K tokens, 64K window).
-///
-/// Deflate function accepts BlockWriterType so we can change that in test to test
-/// just tokenization part.
-///
-fn Deflate(comptime container: Container, comptime WriterType: type, comptime BlockWriterType: type) type {
-    return struct {
-        lookup: Lookup = .{},
-        win: SlidingWindow = .{},
-        tokens: Tokens = .{},
-        wrt: WriterType,
-        block_writer: BlockWriterType,
-        level: LevelArgs,
-        hasher: container.Hasher() = .{},
-
-        // Match and literal at the previous position.
-        // Used for lazy match finding in processWindow.
-        prev_match: ?Token = null,
-        prev_literal: ?u8 = null,
-
-        const Self = @This();
-
-        pub fn init(wrt: WriterType, options: Options) !Self {
-            const self = Self{
-                .wrt = wrt,
-                .block_writer = BlockWriterType.init(wrt),
-                .level = LevelArgs.get(options.level),
-            };
-            try container.writeHeader(self.wrt);
-            return self;
-        }
-
-        const FlushOption = enum { none, flush, final };
-
-        // Process data in window and create tokens. If token buffer is full
-        // flush tokens to the token writer. In the case of `flush` or `final`
-        // option it will process all data from the window. In the `none` case
-        // it will preserve some data for the next match.
-        fn tokenize(self: *Self, flush_opt: FlushOption) !void {
-            // flush - process all data from window
-            const should_flush = (flush_opt != .none);
-
-            // While there is data in active lookahead buffer.
-            while (self.win.activeLookahead(should_flush)) |lh| {
-                var step: u16 = 1; // 1 in the case of literal, match length otherwise
-                const pos: u16 = self.win.pos();
-                const literal = lh[0]; // literal at current position
-                const min_len: u16 = if (self.prev_match) |m| m.length() else 0;
-
-                // Try to find match at least min_len long.
-                if (self.findMatch(pos, lh, min_len)) |match| {
-                    // Found better match than previous.
-                    try self.addPrevLiteral();
-
-                    // Is found match length good enough?
-                    if (match.length() >= self.level.lazy) {
-                        // Don't try to lazy find better match, use this.
-                        step = try self.addMatch(match);
-                    } else {
-                        // Store this match.
-                        self.prev_literal = literal;
-                        self.prev_match = match;
-                    }
-                } else {
-                    // There is no better match at current pos then it was previous.
-                    // Write previous match or literal.
-                    if (self.prev_match) |m| {
-                        // Write match from previous position.
-                        step = try self.addMatch(m) - 1; // we already advanced 1 from previous position
-                    } else {
-                        // No match at previous position.
-                        // Write previous literal if any, and remember this literal.
-                        try self.addPrevLiteral();
-                        self.prev_literal = literal;
-                    }
-                }
-                // Advance window and add hashes.
-                self.windowAdvance(step, lh, pos);
-            }
-
-            if (should_flush) {
-                // In the case of flushing, last few lookahead buffers were smaller then min match len.
-                // So only last literal can be unwritten.
-                assert(self.prev_match == null);
-                try self.addPrevLiteral();
-                self.prev_literal = null;
-
-                try self.flushTokens(flush_opt);
-            }
-        }
-
-        fn windowAdvance(self: *Self, step: u16, lh: []const u8, pos: u16) void {
-            // current position is already added in findMatch
-            self.lookup.bulkAdd(lh[1..], step - 1, pos + 1);
-            self.win.advance(step);
-        }
-
-        // Add previous literal (if any) to the tokens list.
-        fn addPrevLiteral(self: *Self) !void {
-            if (self.prev_literal) |l| try self.addToken(Token.initLiteral(l));
-        }
-
-        // Add match to the tokens list, reset prev pointers.
-        // Returns length of the added match.
-        fn addMatch(self: *Self, m: Token) !u16 {
-            try self.addToken(m);
-            self.prev_literal = null;
-            self.prev_match = null;
-            return m.length();
-        }
-
-        fn addToken(self: *Self, token: Token) !void {
-            self.tokens.add(token);
-            if (self.tokens.full()) try self.flushTokens(.none);
-        }
-
-        // Finds largest match in the history window with the data at current pos.
-        fn findMatch(self: *Self, pos: u16, lh: []const u8, min_len: u16) ?Token {
-            var len: u16 = min_len;
-            // Previous location with the same hash (same 4 bytes).
-            var prev_pos = self.lookup.add(lh, pos);
-            // Last found match.
-            var match: ?Token = null;
-
-            // How much back-references to try, performance knob.
-            var chain: usize = self.level.chain;
-            if (len >= self.level.good) {
-                // If we've got a match that's good enough, only look in 1/4 the chain.
-                chain >>= 2;
-            }
-
-            // Hot path loop!
-            while (prev_pos > 0 and chain > 0) : (chain -= 1) {
-                const distance = pos - prev_pos;
-                if (distance > consts.match.max_distance)
-                    break;
-
-                const new_len = self.win.match(prev_pos, pos, len);
-                if (new_len > len) {
-                    match = Token.initMatch(@intCast(distance), new_len);
-                    if (new_len >= self.level.nice) {
-                        // The match is good enough that we don't try to find a better one.
-                        return match;
-                    }
-                    len = new_len;
-                }
-                prev_pos = self.lookup.prev(prev_pos);
-            }
-
-            return match;
-        }
-
-        fn flushTokens(self: *Self, flush_opt: FlushOption) !void {
-            // Pass tokens to the token writer
-            try self.block_writer.write(self.tokens.tokens(), flush_opt == .final, self.win.tokensBuffer());
-            // Stored block ensures byte alignment.
-            // It has 3 bits (final, block_type) and then padding until byte boundary.
-            // After that everything is aligned to the boundary in the stored block.
-            // Empty stored block is Ob000 + (0-7) bits of padding + 0x00 0x00 0xFF 0xFF.
-            // Last 4 bytes are byte aligned.
-            if (flush_opt == .flush) {
-                try self.block_writer.storedBlock("", false);
-            }
-            if (flush_opt != .none) {
-                // Safe to call only when byte aligned or it is OK to add
-                // padding bits (on last byte of the final block).
-                try self.block_writer.flush();
-            }
-            // Reset internal tokens store.
-            self.tokens.reset();
-            // Notify win that tokens are flushed.
-            self.win.flush();
-        }
-
-        // Slide win and if needed lookup tables.
-        fn slide(self: *Self) void {
-            const n = self.win.slide();
-            self.lookup.slide(n);
-        }
-
-        /// Compresses as much data as possible, stops when the reader becomes
-        /// empty. It will introduce some output latency (reading input without
-        /// producing all output) because some data are still in internal
-        /// buffers.
-        ///
-        /// It is up to the caller to call flush (if needed) or finish (required)
-        /// when is need to output any pending data or complete stream.
-        ///
-        pub fn compress(self: *Self, reader: anytype) !void {
-            while (true) {
-                // Fill window from reader
-                const buf = self.win.writable();
-                if (buf.len == 0) {
-                    try self.tokenize(.none);
-                    self.slide();
-                    continue;
-                }
-                const n = try reader.readAll(buf);
-                self.hasher.update(buf[0..n]);
-                self.win.written(n);
-                // Process window
-                try self.tokenize(.none);
-                // Exit when no more data in reader
-                if (n < buf.len) break;
-            }
-        }
-
-        /// Flushes internal buffers to the output writer. Outputs empty stored
-        /// block to sync bit stream to the byte boundary, so that the
-        /// decompressor can get all input data available so far.
-        ///
-        /// It is useful mainly in compressed network protocols, to ensure that
-        /// deflate bit stream can be used as byte stream. May degrade
-        /// compression so it should be used only when necessary.
-        ///
-        /// Completes the current deflate block and follows it with an empty
-        /// stored block that is three zero bits plus filler bits to the next
-        /// byte, followed by four bytes (00 00 ff ff).
-        ///
-        pub fn flush(self: *Self) !void {
-            try self.tokenize(.flush);
-        }
-
-        /// Completes deflate bit stream by writing any pending data as deflate
-        /// final deflate block. HAS to be called once all data are written to
-        /// the compressor as a signal that next block has to have final bit
-        /// set.
-        ///
-        pub fn finish(self: *Self) !void {
-            try self.tokenize(.final);
-            try container.writeFooter(&self.hasher, self.wrt);
-        }
-
-        /// Use another writer while preserving history. Most probably flush
-        /// should be called on old writer before setting new.
-        pub fn setWriter(self: *Self, new_writer: WriterType) void {
-            self.block_writer.setWriter(new_writer);
-            self.wrt = new_writer;
-        }
-
-        // Writer interface
-
-        pub const Writer = io.GenericWriter(*Self, Error, write);
-        pub const Error = BlockWriterType.Error;
-
-        /// Write `input` of uncompressed data.
-        /// See compress.
-        pub fn write(self: *Self, input: []const u8) !usize {
-            var fbs = io.fixedBufferStream(input);
-            try self.compress(fbs.reader());
-            return input.len;
-        }
-
-        pub fn writer(self: *Self) Writer {
-            return .{ .context = self };
-        }
-    };
-}
-
-// Tokens store
-const Tokens = struct {
-    list: [consts.deflate.tokens]Token = undefined,
-    pos: usize = 0,
-
-    fn add(self: *Tokens, t: Token) void {
-        self.list[self.pos] = t;
-        self.pos += 1;
-    }
-
-    fn full(self: *Tokens) bool {
-        return self.pos == self.list.len;
-    }
-
-    fn reset(self: *Tokens) void {
-        self.pos = 0;
-    }
-
-    fn tokens(self: *Tokens) []const Token {
-        return self.list[0..self.pos];
-    }
-};
-
-/// Creates huffman only deflate blocks. Disables Lempel-Ziv match searching and
-/// only performs Huffman entropy encoding. Results in faster compression, much
-/// less memory requirements during compression but bigger compressed sizes.
-pub const huffman = struct {
-    pub fn compress(comptime container: Container, reader: anytype, writer: anytype) !void {
-        var c = try huffman.compressor(container, writer);
-        try c.compress(reader);
-        try c.finish();
-    }
-
-    pub fn Compressor(comptime container: Container, comptime WriterType: type) type {
-        return SimpleCompressor(.huffman, container, WriterType);
-    }
-
-    pub fn compressor(comptime container: Container, writer: anytype) !huffman.Compressor(container, @TypeOf(writer)) {
-        return try huffman.Compressor(container, @TypeOf(writer)).init(writer);
-    }
-};
-
-/// Creates store blocks only. Data are not compressed only packed into deflate
-/// store blocks. That adds 9 bytes of header for each block. Max stored block
-/// size is 64K. Block is emitted when flush is called on on finish.
-pub const store = struct {
-    pub fn compress(comptime container: Container, reader: anytype, writer: anytype) !void {
-        var c = try store.compressor(container, writer);
-        try c.compress(reader);
-        try c.finish();
-    }
-
-    pub fn Compressor(comptime container: Container, comptime WriterType: type) type {
-        return SimpleCompressor(.store, container, WriterType);
-    }
-
-    pub fn compressor(comptime container: Container, writer: anytype) !store.Compressor(container, @TypeOf(writer)) {
-        return try store.Compressor(container, @TypeOf(writer)).init(writer);
-    }
-};
-
-const SimpleCompressorKind = enum {
-    huffman,
-    store,
-};
-
-fn simpleCompressor(
-    comptime kind: SimpleCompressorKind,
-    comptime container: Container,
-    writer: anytype,
-) !SimpleCompressor(kind, container, @TypeOf(writer)) {
-    return try SimpleCompressor(kind, container, @TypeOf(writer)).init(writer);
-}
-
-fn SimpleCompressor(
-    comptime kind: SimpleCompressorKind,
-    comptime container: Container,
-    comptime WriterType: type,
-) type {
-    const BlockWriterType = BlockWriter(WriterType);
-    return struct {
-        buffer: [65535]u8 = undefined, // because store blocks are limited to 65535 bytes
-        wp: usize = 0,
-
-        wrt: WriterType,
-        block_writer: BlockWriterType,
-        hasher: container.Hasher() = .{},
-
-        const Self = @This();
-
-        pub fn init(wrt: WriterType) !Self {
-            const self = Self{
-                .wrt = wrt,
-                .block_writer = BlockWriterType.init(wrt),
-            };
-            try container.writeHeader(self.wrt);
-            return self;
-        }
-
-        pub fn flush(self: *Self) !void {
-            try self.flushBuffer(false);
-            try self.block_writer.storedBlock("", false);
-            try self.block_writer.flush();
-        }
-
-        pub fn finish(self: *Self) !void {
-            try self.flushBuffer(true);
-            try self.block_writer.flush();
-            try container.writeFooter(&self.hasher, self.wrt);
-        }
-
-        fn flushBuffer(self: *Self, final: bool) !void {
-            const buf = self.buffer[0..self.wp];
-            switch (kind) {
-                .huffman => try self.block_writer.huffmanBlock(buf, final),
-                .store => try self.block_writer.storedBlock(buf, final),
-            }
-            self.wp = 0;
-        }
-
-        // Writes all data from the input reader of uncompressed data.
-        // It is up to the caller to call flush or finish if there is need to
-        // output compressed blocks.
-        pub fn compress(self: *Self, reader: anytype) !void {
-            while (true) {
-                // read from rdr into buffer
-                const buf = self.buffer[self.wp..];
-                if (buf.len == 0) {
-                    try self.flushBuffer(false);
-                    continue;
-                }
-                const n = try reader.readAll(buf);
-                self.hasher.update(buf[0..n]);
-                self.wp += n;
-                if (n < buf.len) break; // no more data in reader
-            }
-        }
-
-        // Writer interface
-
-        pub const Writer = io.GenericWriter(*Self, Error, write);
-        pub const Error = BlockWriterType.Error;
-
-        // Write `input` of uncompressed data.
-        pub fn write(self: *Self, input: []const u8) !usize {
-            var fbs = io.fixedBufferStream(input);
-            try self.compress(fbs.reader());
-            return input.len;
-        }
-
-        pub fn writer(self: *Self) Writer {
-            return .{ .context = self };
-        }
-    };
-}
-
-const builtin = @import("builtin");
-
-test "tokenization" {
-    const L = Token.initLiteral;
-    const M = Token.initMatch;
-
-    const cases = [_]struct {
-        data: []const u8,
-        tokens: []const Token,
-    }{
-        .{
-            .data = "Blah blah blah blah blah!",
-            .tokens = &[_]Token{ L('B'), L('l'), L('a'), L('h'), L(' '), L('b'), M(5, 18), L('!') },
-        },
-        .{
-            .data = "ABCDEABCD ABCDEABCD",
-            .tokens = &[_]Token{
-                L('A'), L('B'),   L('C'), L('D'), L('E'), L('A'), L('B'), L('C'), L('D'), L(' '),
-                L('A'), M(10, 8),
-            },
-        },
-    };
-
-    for (cases) |c| {
-        inline for (Container.list) |container| { // for each wrapping
-
-            var cw = io.countingWriter(io.null_writer);
-            const cww = cw.writer();
-            var df = try Deflate(container, @TypeOf(cww), TestTokenWriter).init(cww, .{});
-
-            _ = try df.write(c.data);
-            try df.flush();
-
-            // df.token_writer.show();
-            try expect(df.block_writer.pos == c.tokens.len); // number of tokens written
-            try testing.expectEqualSlices(Token, df.block_writer.get(), c.tokens); // tokens match
-
-            try testing.expectEqual(container.headerSize(), cw.bytes_written);
-            try df.finish();
-            try testing.expectEqual(container.size(), cw.bytes_written);
-        }
-    }
-}
-
-// Tests that tokens written are equal to expected token list.
-const TestTokenWriter = struct {
-    const Self = @This();
-
-    pos: usize = 0,
-    actual: [128]Token = undefined,
-
-    pub fn init(_: anytype) Self {
-        return .{};
-    }
-    pub fn write(self: *Self, tokens: []const Token, _: bool, _: ?[]const u8) !void {
-        for (tokens) |t| {
-            self.actual[self.pos] = t;
-            self.pos += 1;
-        }
-    }
-
-    pub fn storedBlock(_: *Self, _: []const u8, _: bool) !void {}
-
-    pub fn get(self: *Self) []Token {
-        return self.actual[0..self.pos];
-    }
-
-    pub fn show(self: *Self) void {
-        print("\n", .{});
-        for (self.get()) |t| {
-            t.show();
-        }
-    }
-
-    pub fn flush(_: *Self) !void {}
-};
-
-test "file tokenization" {
-    const levels = [_]Level{ .level_4, .level_5, .level_6, .level_7, .level_8, .level_9 };
-    const cases = [_]struct {
-        data: []const u8, // uncompressed content
-        // expected number of tokens producet in deflate tokenization
-        tokens_count: [levels.len]usize = .{0} ** levels.len,
-    }{
-        .{
-            .data = @embedFile("testdata/rfc1951.txt"),
-            .tokens_count = .{ 7675, 7672, 7599, 7594, 7598, 7599 },
-        },
-
-        .{
-            .data = @embedFile("testdata/block_writer/huffman-null-max.input"),
-            .tokens_count = .{ 257, 257, 257, 257, 257, 257 },
-        },
-        .{
-            .data = @embedFile("testdata/block_writer/huffman-pi.input"),
-            .tokens_count = .{ 2570, 2564, 2564, 2564, 2564, 2564 },
-        },
-        .{
-            .data = @embedFile("testdata/block_writer/huffman-text.input"),
-            .tokens_count = .{ 235, 234, 234, 234, 234, 234 },
-        },
-        .{
-            .data = @embedFile("testdata/fuzz/roundtrip1.input"),
-            .tokens_count = .{ 333, 331, 331, 331, 331, 331 },
-        },
-        .{
-            .data = @embedFile("testdata/fuzz/roundtrip2.input"),
-            .tokens_count = .{ 334, 334, 334, 334, 334, 334 },
-        },
-    };
-
-    for (cases) |case| { // for each case
-        const data = case.data;
-
-        for (levels, 0..) |level, i| { // for each compression level
-            var original = io.fixedBufferStream(data);
-
-            // buffer for decompressed data
-            var al = std.ArrayList(u8).init(testing.allocator);
-            defer al.deinit();
-            const writer = al.writer();
-
-            // create compressor
-            const WriterType = @TypeOf(writer);
-            const TokenWriter = TokenDecoder(@TypeOf(writer));
-            var cmp = try Deflate(.raw, WriterType, TokenWriter).init(writer, .{ .level = level });
-
-            // Stream uncompressed `original` data to the compressor. It will
-            // produce tokens list and pass that list to the TokenDecoder. This
-            // TokenDecoder uses CircularBuffer from inflate to convert list of
-            // tokens back to the uncompressed stream.
-            try cmp.compress(original.reader());
-            try cmp.flush();
-            const expected_count = case.tokens_count[i];
-            const actual = cmp.block_writer.tokens_count;
-            if (expected_count == 0) {
-                print("actual token count {d}\n", .{actual});
-            } else {
-                try testing.expectEqual(expected_count, actual);
-            }
-
-            try testing.expectEqual(data.len, al.items.len);
-            try testing.expectEqualSlices(u8, data, al.items);
-        }
-    }
-}
-
-fn TokenDecoder(comptime WriterType: type) type {
-    return struct {
-        const CircularBuffer = @import("CircularBuffer.zig");
-        hist: CircularBuffer = .{},
-        wrt: WriterType,
-        tokens_count: usize = 0,
-
-        const Self = @This();
-
-        pub fn init(wrt: WriterType) Self {
-            return .{ .wrt = wrt };
-        }
-
-        pub fn write(self: *Self, tokens: []const Token, _: bool, _: ?[]const u8) !void {
-            self.tokens_count += tokens.len;
-            for (tokens) |t| {
-                switch (t.kind) {
-                    .literal => self.hist.write(t.literal()),
-                    .match => try self.hist.writeMatch(t.length(), t.distance()),
-                }
-                if (self.hist.free() < 285) try self.flushWin();
-            }
-            try self.flushWin();
-        }
-
-        pub fn storedBlock(_: *Self, _: []const u8, _: bool) !void {}
-
-        fn flushWin(self: *Self) !void {
-            while (true) {
-                const buf = self.hist.read();
-                if (buf.len == 0) break;
-                try self.wrt.writeAll(buf);
-            }
-        }
-
-        pub fn flush(_: *Self) !void {}
-    };
-}
-
-test "store simple compressor" {
-    const data = "Hello world!";
-    const expected = [_]u8{
-        0x1, // block type 0, final bit set
-        0xc, 0x0, // len = 12
-        0xf3, 0xff, // ~len
-        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', '!', //
-        //0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21,
-    };
-
-    var fbs = std.io.fixedBufferStream(data);
-    var al = std.ArrayList(u8).init(testing.allocator);
-    defer al.deinit();
-
-    var cmp = try store.compressor(.raw, al.writer());
-    try cmp.compress(fbs.reader());
-    try cmp.finish();
-    try testing.expectEqualSlices(u8, &expected, al.items);
-
-    fbs.reset();
-    try al.resize(0);
-
-    // huffman only compresoor will also emit store block for this small sample
-    var hc = try huffman.compressor(.raw, al.writer());
-    try hc.compress(fbs.reader());
-    try hc.finish();
-    try testing.expectEqualSlices(u8, &expected, al.items);
-}
diff --git a/lib/std/compress/flate/huffman_decoder.zig b/lib/std/compress/flate/huffman_decoder.zig
deleted file mode 100644
index abff915f76..0000000000
--- a/lib/std/compress/flate/huffman_decoder.zig
+++ /dev/null
@@ -1,302 +0,0 @@
-const std = @import("std");
-const testing = std.testing;
-
-pub const Symbol = packed struct {
-    pub const Kind = enum(u2) {
-        literal,
-        end_of_block,
-        match,
-    };
-
-    symbol: u8 = 0, // symbol from alphabet
-    code_bits: u4 = 0, // number of bits in code 0-15
-    kind: Kind = .literal,
-
-    code: u16 = 0, // huffman code of the symbol
-    next: u16 = 0, // pointer to the next symbol in linked list
-    // it is safe to use 0 as null pointer, when sorted 0 has shortest code and fits into lookup
-
-    // Sorting less than function.
-    pub fn asc(_: void, a: Symbol, b: Symbol) bool {
-        if (a.code_bits == b.code_bits) {
-            if (a.kind == b.kind) {
-                return a.symbol < b.symbol;
-            }
-            return @intFromEnum(a.kind) < @intFromEnum(b.kind);
-        }
-        return a.code_bits < b.code_bits;
-    }
-};
-
-pub const LiteralDecoder = HuffmanDecoder(286, 15, 9);
-pub const DistanceDecoder = HuffmanDecoder(30, 15, 9);
-pub const CodegenDecoder = HuffmanDecoder(19, 7, 7);
-
-pub const Error = error{
-    InvalidCode,
-    OversubscribedHuffmanTree,
-    IncompleteHuffmanTree,
-    MissingEndOfBlockCode,
-};
-
-/// Creates huffman tree codes from list of code lengths (in `build`).
-///
-/// `find` then finds symbol for code bits. Code can be any length between 1 and
-/// 15 bits. When calling `find` we don't know how many bits will be used to
-/// find symbol. When symbol is returned it has code_bits field which defines
-/// how much we should advance in bit stream.
-///
-/// Lookup table is used to map 15 bit int to symbol. Same symbol is written
-/// many times in this table; 32K places for 286 (at most) symbols.
-/// Small lookup table is optimization for faster search.
-/// It is variation of the algorithm explained in [zlib](https://github.com/madler/zlib/blob/643e17b7498d12ab8d15565662880579692f769d/doc/algorithm.txt#L92)
-/// with difference that we here use statically allocated arrays.
-///
-fn HuffmanDecoder(
-    comptime alphabet_size: u16,
-    comptime max_code_bits: u4,
-    comptime lookup_bits: u4,
-) type {
-    const lookup_shift = max_code_bits - lookup_bits;
-
-    return struct {
-        // all symbols in alaphabet, sorted by code_len, symbol
-        symbols: [alphabet_size]Symbol = undefined,
-        // lookup table code -> symbol
-        lookup: [1 << lookup_bits]Symbol = undefined,
-
-        const Self = @This();
-
-        /// Generates symbols and lookup tables from list of code lens for each symbol.
-        pub fn generate(self: *Self, lens: []const u4) !void {
-            try checkCompleteness(lens);
-
-            // init alphabet with code_bits
-            for (self.symbols, 0..) |_, i| {
-                const cb: u4 = if (i < lens.len) lens[i] else 0;
-                self.symbols[i] = if (i < 256)
-                    .{ .kind = .literal, .symbol = @intCast(i), .code_bits = cb }
-                else if (i == 256)
-                    .{ .kind = .end_of_block, .symbol = 0xff, .code_bits = cb }
-                else
-                    .{ .kind = .match, .symbol = @intCast(i - 257), .code_bits = cb };
-            }
-            std.sort.heap(Symbol, &self.symbols, {}, Symbol.asc);
-
-            // reset lookup table
-            for (0..self.lookup.len) |i| {
-                self.lookup[i] = .{};
-            }
-
-            // assign code to symbols
-            // reference: https://youtu.be/9_YEGLe33NA?list=PLU4IQLU9e_OrY8oASHx0u3IXAL9TOdidm&t=2639
-            var code: u16 = 0;
-            var idx: u16 = 0;
-            for (&self.symbols, 0..) |*sym, pos| {
-                if (sym.code_bits == 0) continue; // skip unused
-                sym.code = code;
-
-                const next_code = code + (@as(u16, 1) << (max_code_bits - sym.code_bits));
-                const next_idx = next_code >> lookup_shift;
-
-                if (next_idx > self.lookup.len or idx >= self.lookup.len) break;
-                if (sym.code_bits <= lookup_bits) {
-                    // fill small lookup table
-                    for (idx..next_idx) |j|
-                        self.lookup[j] = sym.*;
-                } else {
-                    // insert into linked table starting at root
-                    const root = &self.lookup[idx];
-                    const root_next = root.next;
-                    root.next = @intCast(pos);
-                    sym.next = root_next;
-                }
-
-                idx = next_idx;
-                code = next_code;
-            }
-        }
-
-        /// Given the list of code lengths check that it represents a canonical
-        /// Huffman code for n symbols.
-        ///
-        /// Reference: https://github.com/madler/zlib/blob/5c42a230b7b468dff011f444161c0145b5efae59/contrib/puff/puff.c#L340
-        fn checkCompleteness(lens: []const u4) !void {
-            if (alphabet_size == 286)
-                if (lens[256] == 0) return error.MissingEndOfBlockCode;
-
-            var count = [_]u16{0} ** (@as(usize, max_code_bits) + 1);
-            var max: usize = 0;
-            for (lens) |n| {
-                if (n == 0) continue;
-                if (n > max) max = n;
-                count[n] += 1;
-            }
-            if (max == 0) // empty tree
-                return;
-
-            // check for an over-subscribed or incomplete set of lengths
-            var left: usize = 1; // one possible code of zero length
-            for (1..count.len) |len| {
-                left <<= 1; // one more bit, double codes left
-                if (count[len] > left)
-                    return error.OversubscribedHuffmanTree;
-                left -= count[len]; // deduct count from possible codes
-            }
-            if (left > 0) { // left > 0 means incomplete
-                // incomplete code ok only for single length 1 code
-                if (max_code_bits > 7 and max == count[0] + count[1]) return;
-                return error.IncompleteHuffmanTree;
-            }
-        }
-
-        /// Finds symbol for lookup table code.
-        pub fn find(self: *Self, code: u16) !Symbol {
-            // try to find in lookup table
-            const idx = code >> lookup_shift;
-            const sym = self.lookup[idx];
-            if (sym.code_bits != 0) return sym;
-            // if not use linked list of symbols with same prefix
-            return self.findLinked(code, sym.next);
-        }
-
-        inline fn findLinked(self: *Self, code: u16, start: u16) !Symbol {
-            var pos = start;
-            while (pos > 0) {
-                const sym = self.symbols[pos];
-                const shift = max_code_bits - sym.code_bits;
-                // compare code_bits number of upper bits
-                if ((code ^ sym.code) >> shift == 0) return sym;
-                pos = sym.next;
-            }
-            return error.InvalidCode;
-        }
-    };
-}
-
-test "init/find" {
-    // example data from: https://youtu.be/SJPvNi4HrWQ?t=8423
-    const code_lens = [_]u4{ 4, 3, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 3, 2 };
-    var h: CodegenDecoder = .{};
-    try h.generate(&code_lens);
-
-    const expected = [_]struct {
-        sym: Symbol,
-        code: u16,
-    }{
-        .{
-            .code = 0b00_00000,
-            .sym = .{ .symbol = 3, .code_bits = 2 },
-        },
-        .{
-            .code = 0b01_00000,
-            .sym = .{ .symbol = 18, .code_bits = 2 },
-        },
-        .{
-            .code = 0b100_0000,
-            .sym = .{ .symbol = 1, .code_bits = 3 },
-        },
-        .{
-            .code = 0b101_0000,
-            .sym = .{ .symbol = 4, .code_bits = 3 },
-        },
-        .{
-            .code = 0b110_0000,
-            .sym = .{ .symbol = 17, .code_bits = 3 },
-        },
-        .{
-            .code = 0b1110_000,
-            .sym = .{ .symbol = 0, .code_bits = 4 },
-        },
-        .{
-            .code = 0b1111_000,
-            .sym = .{ .symbol = 16, .code_bits = 4 },
-        },
-    };
-
-    // unused symbols
-    for (0..12) |i| {
-        try testing.expectEqual(0, h.symbols[i].code_bits);
-    }
-    // used, from index 12
-    for (expected, 12..) |e, i| {
-        try testing.expectEqual(e.sym.symbol, h.symbols[i].symbol);
-        try testing.expectEqual(e.sym.code_bits, h.symbols[i].code_bits);
-        const sym_from_code = try h.find(e.code);
-        try testing.expectEqual(e.sym.symbol, sym_from_code.symbol);
-    }
-
-    // All possible codes for each symbol.
-    // Lookup table has 126 elements, to cover all possible 7 bit codes.
-    for (0b0000_000..0b0100_000) |c| // 0..32 (32)
-        try testing.expectEqual(3, (try h.find(@intCast(c))).symbol);
-
-    for (0b0100_000..0b1000_000) |c| // 32..64 (32)
-        try testing.expectEqual(18, (try h.find(@intCast(c))).symbol);
-
-    for (0b1000_000..0b1010_000) |c| // 64..80 (16)
-        try testing.expectEqual(1, (try h.find(@intCast(c))).symbol);
-
-    for (0b1010_000..0b1100_000) |c| // 80..96 (16)
-        try testing.expectEqual(4, (try h.find(@intCast(c))).symbol);
-
-    for (0b1100_000..0b1110_000) |c| // 96..112 (16)
-        try testing.expectEqual(17, (try h.find(@intCast(c))).symbol);
-
-    for (0b1110_000..0b1111_000) |c| // 112..120 (8)
-        try testing.expectEqual(0, (try h.find(@intCast(c))).symbol);
-
-    for (0b1111_000..0b1_0000_000) |c| // 120...128 (8)
-        try testing.expectEqual(16, (try h.find(@intCast(c))).symbol);
-}
-
-test "encode/decode literals" {
-    const LiteralEncoder = @import("huffman_encoder.zig").LiteralEncoder;
-
-    for (1..286) |j| { // for all different number of codes
-        var enc: LiteralEncoder = .{};
-        // create frequencies
-        var freq = [_]u16{0} ** 286;
-        freq[256] = 1; // ensure we have end of block code
-        for (&freq, 1..) |*f, i| {
-            if (i % j == 0)
-                f.* = @intCast(i);
-        }
-
-        // encoder from frequencies
-        enc.generate(&freq, 15);
-
-        // get code_lens from encoder
-        var code_lens = [_]u4{0} ** 286;
-        for (code_lens, 0..) |_, i| {
-            code_lens[i] = @intCast(enc.codes[i].len);
-        }
-        // generate decoder from code lens
-        var dec: LiteralDecoder = .{};
-        try dec.generate(&code_lens);
-
-        // expect decoder code to match original encoder code
-        for (dec.symbols) |s| {
-            if (s.code_bits == 0) continue;
-            const c_code: u16 = @bitReverse(@as(u15, @intCast(s.code)));
-            const symbol: u16 = switch (s.kind) {
-                .literal => s.symbol,
-                .end_of_block => 256,
-                .match => @as(u16, s.symbol) + 257,
-            };
-
-            const c = enc.codes[symbol];
-            try testing.expect(c.code == c_code);
-        }
-
-        // find each symbol by code
-        for (enc.codes) |c| {
-            if (c.len == 0) continue;
-
-            const s_code: u15 = @bitReverse(@as(u15, @intCast(c.code)));
-            const s = try dec.find(s_code);
-            try testing.expect(s.code == s_code);
-            try testing.expect(s.code_bits == c.len);
-        }
-    }
-}
diff --git a/lib/std/compress/flate/huffman_encoder.zig b/lib/std/compress/flate/huffman_encoder.zig
deleted file mode 100644
index 3e92e55a63..0000000000
--- a/lib/std/compress/flate/huffman_encoder.zig
+++ /dev/null
@@ -1,536 +0,0 @@
-const std = @import("std");
-const assert = std.debug.assert;
-const math = std.math;
-const mem = std.mem;
-const sort = std.sort;
-const testing = std.testing;
-
-const consts = @import("consts.zig").huffman;
-
-const LiteralNode = struct {
-    literal: u16,
-    freq: u16,
-};
-
-// Describes the state of the constructed tree for a given depth.
-const LevelInfo = struct {
-    // Our level.  for better printing
-    level: u32,
-
-    // The frequency of the last node at this level
-    last_freq: u32,
-
-    // The frequency of the next character to add to this level
-    next_char_freq: u32,
-
-    // The frequency of the next pair (from level below) to add to this level.
-    // Only valid if the "needed" value of the next lower level is 0.
-    next_pair_freq: u32,
-
-    // The number of chains remaining to generate for this level before moving
-    // up to the next level
-    needed: u32,
-};
-
-// hcode is a huffman code with a bit code and bit length.
-pub const HuffCode = struct {
-    code: u16 = 0,
-    len: u16 = 0,
-
-    // set sets the code and length of an hcode.
-    fn set(self: *HuffCode, code: u16, length: u16) void {
-        self.len = length;
-        self.code = code;
-    }
-};
-
-pub fn HuffmanEncoder(comptime size: usize) type {
-    return struct {
-        codes: [size]HuffCode = undefined,
-        // Reusable buffer with the longest possible frequency table.
-        freq_cache: [consts.max_num_frequencies + 1]LiteralNode = undefined,
-        bit_count: [17]u32 = undefined,
-        lns: []LiteralNode = undefined, // sorted by literal, stored to avoid repeated allocation in generate
-        lfs: []LiteralNode = undefined, // sorted by frequency, stored to avoid repeated allocation in generate
-
-        const Self = @This();
-
-        // Update this Huffman Code object to be the minimum code for the specified frequency count.
-        //
-        // freq  An array of frequencies, in which frequency[i] gives the frequency of literal i.
-        // max_bits  The maximum number of bits to use for any literal.
-        pub fn generate(self: *Self, freq: []u16, max_bits: u32) void {
-            var list = self.freq_cache[0 .. freq.len + 1];
-            // Number of non-zero literals
-            var count: u32 = 0;
-            // Set list to be the set of all non-zero literals and their frequencies
-            for (freq, 0..) |f, i| {
-                if (f != 0) {
-                    list[count] = LiteralNode{ .literal = @as(u16, @intCast(i)), .freq = f };
-                    count += 1;
-                } else {
-                    list[count] = LiteralNode{ .literal = 0x00, .freq = 0 };
-                    self.codes[i].len = 0;
-                }
-            }
-            list[freq.len] = LiteralNode{ .literal = 0x00, .freq = 0 };
-
-            list = list[0..count];
-            if (count <= 2) {
-                // Handle the small cases here, because they are awkward for the general case code. With
-                // two or fewer literals, everything has bit length 1.
-                for (list, 0..) |node, i| {
-                    // "list" is in order of increasing literal value.
-                    self.codes[node.literal].set(@as(u16, @intCast(i)), 1);
-                }
-                return;
-            }
-            self.lfs = list;
-            mem.sort(LiteralNode, self.lfs, {}, byFreq);
-
-            // Get the number of literals for each bit count
-            const bit_count = self.bitCounts(list, max_bits);
-            // And do the assignment
-            self.assignEncodingAndSize(bit_count, list);
-        }
-
-        pub fn bitLength(self: *Self, freq: []u16) u32 {
-            var total: u32 = 0;
-            for (freq, 0..) |f, i| {
-                if (f != 0) {
-                    total += @as(u32, @intCast(f)) * @as(u32, @intCast(self.codes[i].len));
-                }
-            }
-            return total;
-        }
-
-        // Return the number of literals assigned to each bit size in the Huffman encoding
-        //
-        // This method is only called when list.len >= 3
-        // The cases of 0, 1, and 2 literals are handled by special case code.
-        //
-        // list: An array of the literals with non-zero frequencies
-        // and their associated frequencies. The array is in order of increasing
-        // frequency, and has as its last element a special element with frequency
-        // std.math.maxInt(i32)
-        //
-        // max_bits: The maximum number of bits that should be used to encode any literal.
-        // Must be less than 16.
-        //
-        // Returns an integer array in which array[i] indicates the number of literals
-        // that should be encoded in i bits.
-        fn bitCounts(self: *Self, list: []LiteralNode, max_bits_to_use: usize) []u32 {
-            var max_bits = max_bits_to_use;
-            const n = list.len;
-            const max_bits_limit = 16;
-
-            assert(max_bits < max_bits_limit);
-
-            // The tree can't have greater depth than n - 1, no matter what. This
-            // saves a little bit of work in some small cases
-            max_bits = @min(max_bits, n - 1);
-
-            // Create information about each of the levels.
-            // A bogus "Level 0" whose sole purpose is so that
-            // level1.prev.needed == 0.  This makes level1.next_pair_freq
-            // be a legitimate value that never gets chosen.
-            var levels: [max_bits_limit]LevelInfo = mem.zeroes([max_bits_limit]LevelInfo);
-            // leaf_counts[i] counts the number of literals at the left
-            // of ancestors of the rightmost node at level i.
-            // leaf_counts[i][j] is the number of literals at the left
-            // of the level j ancestor.
-            var leaf_counts: [max_bits_limit][max_bits_limit]u32 = mem.zeroes([max_bits_limit][max_bits_limit]u32);
-
-            {
-                var level = @as(u32, 1);
-                while (level <= max_bits) : (level += 1) {
-                    // For every level, the first two items are the first two characters.
-                    // We initialize the levels as if we had already figured this out.
-                    levels[level] = LevelInfo{
-                        .level = level,
-                        .last_freq = list[1].freq,
-                        .next_char_freq = list[2].freq,
-                        .next_pair_freq = list[0].freq + list[1].freq,
-                        .needed = 0,
-                    };
-                    leaf_counts[level][level] = 2;
-                    if (level == 1) {
-                        levels[level].next_pair_freq = math.maxInt(i32);
-                    }
-                }
-            }
-
-            // We need a total of 2*n - 2 items at top level and have already generated 2.
-            levels[max_bits].needed = 2 * @as(u32, @intCast(n)) - 4;
-
-            {
-                var level = max_bits;
-                while (true) {
-                    var l = &levels[level];
-                    if (l.next_pair_freq == math.maxInt(i32) and l.next_char_freq == math.maxInt(i32)) {
-                        // We've run out of both leaves and pairs.
-                        // End all calculations for this level.
-                        // To make sure we never come back to this level or any lower level,
-                        // set next_pair_freq impossibly large.
-                        l.needed = 0;
-                        levels[level + 1].next_pair_freq = math.maxInt(i32);
-                        level += 1;
-                        continue;
-                    }
-
-                    const prev_freq = l.last_freq;
-                    if (l.next_char_freq < l.next_pair_freq) {
-                        // The next item on this row is a leaf node.
-                        const next = leaf_counts[level][level] + 1;
-                        l.last_freq = l.next_char_freq;
-                        // Lower leaf_counts are the same of the previous node.
-                        leaf_counts[level][level] = next;
-                        if (next >= list.len) {
-                            l.next_char_freq = maxNode().freq;
-                        } else {
-                            l.next_char_freq = list[next].freq;
-                        }
-                    } else {
-                        // The next item on this row is a pair from the previous row.
-                        // next_pair_freq isn't valid until we generate two
-                        // more values in the level below
-                        l.last_freq = l.next_pair_freq;
-                        // Take leaf counts from the lower level, except counts[level] remains the same.
-                        @memcpy(leaf_counts[level][0..level], leaf_counts[level - 1][0..level]);
-                        levels[l.level - 1].needed = 2;
-                    }
-
-                    l.needed -= 1;
-                    if (l.needed == 0) {
-                        // We've done everything we need to do for this level.
-                        // Continue calculating one level up. Fill in next_pair_freq
-                        // of that level with the sum of the two nodes we've just calculated on
-                        // this level.
-                        if (l.level == max_bits) {
-                            // All done!
-                            break;
-                        }
-                        levels[l.level + 1].next_pair_freq = prev_freq + l.last_freq;
-                        level += 1;
-                    } else {
-                        // If we stole from below, move down temporarily to replenish it.
-                        while (levels[level - 1].needed > 0) {
-                            level -= 1;
-                            if (level == 0) {
-                                break;
-                            }
-                        }
-                    }
-                }
-            }
-
-            // Somethings is wrong if at the end, the top level is null or hasn't used
-            // all of the leaves.
-            assert(leaf_counts[max_bits][max_bits] == n);
-
-            var bit_count = self.bit_count[0 .. max_bits + 1];
-            var bits: u32 = 1;
-            const counts = &leaf_counts[max_bits];
-            {
-                var level = max_bits;
-                while (level > 0) : (level -= 1) {
-                    // counts[level] gives the number of literals requiring at least "bits"
-                    // bits to encode.
-                    bit_count[bits] = counts[level] - counts[level - 1];
-                    bits += 1;
-                    if (level == 0) {
-                        break;
-                    }
-                }
-            }
-            return bit_count;
-        }
-
-        // Look at the leaves and assign them a bit count and an encoding as specified
-        // in RFC 1951 3.2.2
-        fn assignEncodingAndSize(self: *Self, bit_count: []u32, list_arg: []LiteralNode) void {
-            var code = @as(u16, 0);
-            var list = list_arg;
-
-            for (bit_count, 0..) |bits, n| {
-                code <<= 1;
-                if (n == 0 or bits == 0) {
-                    continue;
-                }
-                // The literals list[list.len-bits] .. list[list.len-bits]
-                // are encoded using "bits" bits, and get the values
-                // code, code + 1, ....  The code values are
-                // assigned in literal order (not frequency order).
-                const chunk = list[list.len - @as(u32, @intCast(bits)) ..];
-
-                self.lns = chunk;
-                mem.sort(LiteralNode, self.lns, {}, byLiteral);
-
-                for (chunk) |node| {
-                    self.codes[node.literal] = HuffCode{
-                        .code = bitReverse(u16, code, @as(u5, @intCast(n))),
-                        .len = @as(u16, @intCast(n)),
-                    };
-                    code += 1;
-                }
-                list = list[0 .. list.len - @as(u32, @intCast(bits))];
-            }
-        }
-    };
-}
-
-fn maxNode() LiteralNode {
-    return LiteralNode{
-        .literal = math.maxInt(u16),
-        .freq = math.maxInt(u16),
-    };
-}
-
-pub fn huffmanEncoder(comptime size: u32) HuffmanEncoder(size) {
-    return .{};
-}
-
-pub const LiteralEncoder = HuffmanEncoder(consts.max_num_frequencies);
-pub const DistanceEncoder = HuffmanEncoder(consts.distance_code_count);
-pub const CodegenEncoder = HuffmanEncoder(19);
-
-// Generates a HuffmanCode corresponding to the fixed literal table
-pub fn fixedLiteralEncoder() LiteralEncoder {
-    var h: LiteralEncoder = undefined;
-    var ch: u16 = 0;
-
-    while (ch < consts.max_num_frequencies) : (ch += 1) {
-        var bits: u16 = undefined;
-        var size: u16 = undefined;
-        switch (ch) {
-            0...143 => {
-                // size 8, 000110000  .. 10111111
-                bits = ch + 48;
-                size = 8;
-            },
-            144...255 => {
-                // size 9, 110010000 .. 111111111
-                bits = ch + 400 - 144;
-                size = 9;
-            },
-            256...279 => {
-                // size 7, 0000000 .. 0010111
-                bits = ch - 256;
-                size = 7;
-            },
-            else => {
-                // size 8, 11000000 .. 11000111
-                bits = ch + 192 - 280;
-                size = 8;
-            },
-        }
-        h.codes[ch] = HuffCode{ .code = bitReverse(u16, bits, @as(u5, @intCast(size))), .len = size };
-    }
-    return h;
-}
-
-pub fn fixedDistanceEncoder() DistanceEncoder {
-    var h: DistanceEncoder = undefined;
-    for (h.codes, 0..) |_, ch| {
-        h.codes[ch] = HuffCode{ .code = bitReverse(u16, @as(u16, @intCast(ch)), 5), .len = 5 };
-    }
-    return h;
-}
-
-pub fn huffmanDistanceEncoder() DistanceEncoder {
-    var distance_freq = [1]u16{0} ** consts.distance_code_count;
-    distance_freq[0] = 1;
-    // huff_distance is a static distance encoder used for huffman only encoding.
-    // It can be reused since we will not be encoding distance values.
-    var h: DistanceEncoder = .{};
-    h.generate(distance_freq[0..], 15);
-    return h;
-}
-
-fn byLiteral(context: void, a: LiteralNode, b: LiteralNode) bool {
-    _ = context;
-    return a.literal < b.literal;
-}
-
-fn byFreq(context: void, a: LiteralNode, b: LiteralNode) bool {
-    _ = context;
-    if (a.freq == b.freq) {
-        return a.literal < b.literal;
-    }
-    return a.freq < b.freq;
-}
-
-test "generate a Huffman code from an array of frequencies" {
-    var freqs: [19]u16 = [_]u16{
-        8, // 0
-        1, // 1
-        1, // 2
-        2, // 3
-        5, // 4
-        10, // 5
-        9, // 6
-        1, // 7
-        0, // 8
-        0, // 9
-        0, // 10
-        0, // 11
-        0, // 12
-        0, // 13
-        0, // 14
-        0, // 15
-        1, // 16
-        3, // 17
-        5, // 18
-    };
-
-    var enc = huffmanEncoder(19);
-    enc.generate(freqs[0..], 7);
-
-    try testing.expectEqual(@as(u32, 141), enc.bitLength(freqs[0..]));
-
-    try testing.expectEqual(@as(usize, 3), enc.codes[0].len);
-    try testing.expectEqual(@as(usize, 6), enc.codes[1].len);
-    try testing.expectEqual(@as(usize, 6), enc.codes[2].len);
-    try testing.expectEqual(@as(usize, 5), enc.codes[3].len);
-    try testing.expectEqual(@as(usize, 3), enc.codes[4].len);
-    try testing.expectEqual(@as(usize, 2), enc.codes[5].len);
-    try testing.expectEqual(@as(usize, 2), enc.codes[6].len);
-    try testing.expectEqual(@as(usize, 6), enc.codes[7].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[8].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[9].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[10].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[11].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[12].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[13].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[14].len);
-    try testing.expectEqual(@as(usize, 0), enc.codes[15].len);
-    try testing.expectEqual(@as(usize, 6), enc.codes[16].len);
-    try testing.expectEqual(@as(usize, 5), enc.codes[17].len);
-    try testing.expectEqual(@as(usize, 3), enc.codes[18].len);
-
-    try testing.expectEqual(@as(u16, 0x0), enc.codes[5].code);
-    try testing.expectEqual(@as(u16, 0x2), enc.codes[6].code);
-    try testing.expectEqual(@as(u16, 0x1), enc.codes[0].code);
-    try testing.expectEqual(@as(u16, 0x5), enc.codes[4].code);
-    try testing.expectEqual(@as(u16, 0x3), enc.codes[18].code);
-    try testing.expectEqual(@as(u16, 0x7), enc.codes[3].code);
-    try testing.expectEqual(@as(u16, 0x17), enc.codes[17].code);
-    try testing.expectEqual(@as(u16, 0x0f), enc.codes[1].code);
-    try testing.expectEqual(@as(u16, 0x2f), enc.codes[2].code);
-    try testing.expectEqual(@as(u16, 0x1f), enc.codes[7].code);
-    try testing.expectEqual(@as(u16, 0x3f), enc.codes[16].code);
-}
-
-test "generate a Huffman code for the fixed literal table specific to Deflate" {
-    const enc = fixedLiteralEncoder();
-    for (enc.codes) |c| {
-        switch (c.len) {
-            7 => {
-                const v = @bitReverse(@as(u7, @intCast(c.code)));
-                try testing.expect(v <= 0b0010111);
-            },
-            8 => {
-                const v = @bitReverse(@as(u8, @intCast(c.code)));
-                try testing.expect((v >= 0b000110000 and v <= 0b10111111) or
-                    (v >= 0b11000000 and v <= 11000111));
-            },
-            9 => {
-                const v = @bitReverse(@as(u9, @intCast(c.code)));
-                try testing.expect(v >= 0b110010000 and v <= 0b111111111);
-            },
-            else => unreachable,
-        }
-    }
-}
-
-test "generate a Huffman code for the 30 possible relative distances (LZ77 distances) of Deflate" {
-    const enc = fixedDistanceEncoder();
-    for (enc.codes) |c| {
-        const v = @bitReverse(@as(u5, @intCast(c.code)));
-        try testing.expect(v <= 29);
-        try testing.expect(c.len == 5);
-    }
-}
-
-// Reverse bit-by-bit a N-bit code.
-fn bitReverse(comptime T: type, value: T, n: usize) T {
-    const r = @bitReverse(value);
-    return r >> @as(math.Log2Int(T), @intCast(@typeInfo(T).int.bits - n));
-}
-
-test bitReverse {
-    const ReverseBitsTest = struct {
-        in: u16,
-        bit_count: u5,
-        out: u16,
-    };
-
-    const reverse_bits_tests = [_]ReverseBitsTest{
-        .{ .in = 1, .bit_count = 1, .out = 1 },
-        .{ .in = 1, .bit_count = 2, .out = 2 },
-        .{ .in = 1, .bit_count = 3, .out = 4 },
-        .{ .in = 1, .bit_count = 4, .out = 8 },
-        .{ .in = 1, .bit_count = 5, .out = 16 },
-        .{ .in = 17, .bit_count = 5, .out = 17 },
-        .{ .in = 257, .bit_count = 9, .out = 257 },
-        .{ .in = 29, .bit_count = 5, .out = 23 },
-    };
-
-    for (reverse_bits_tests) |h| {
-        const v = bitReverse(u16, h.in, h.bit_count);
-        try std.testing.expectEqual(h.out, v);
-    }
-}
-
-test "fixedLiteralEncoder codes" {
-    var al = std.ArrayList(u8).init(testing.allocator);
-    defer al.deinit();
-    var bw = std.io.bitWriter(.little, al.writer());
-
-    const f = fixedLiteralEncoder();
-    for (f.codes) |c| {
-        try bw.writeBits(c.code, c.len);
-    }
-    try testing.expectEqualSlices(u8, &fixed_codes, al.items);
-}
-
-pub const fixed_codes = [_]u8{
-    0b00001100, 0b10001100, 0b01001100, 0b11001100, 0b00101100, 0b10101100, 0b01101100, 0b11101100,
-    0b00011100, 0b10011100, 0b01011100, 0b11011100, 0b00111100, 0b10111100, 0b01111100, 0b11111100,
-    0b00000010, 0b10000010, 0b01000010, 0b11000010, 0b00100010, 0b10100010, 0b01100010, 0b11100010,
-    0b00010010, 0b10010010, 0b01010010, 0b11010010, 0b00110010, 0b10110010, 0b01110010, 0b11110010,
-    0b00001010, 0b10001010, 0b01001010, 0b11001010, 0b00101010, 0b10101010, 0b01101010, 0b11101010,
-    0b00011010, 0b10011010, 0b01011010, 0b11011010, 0b00111010, 0b10111010, 0b01111010, 0b11111010,
-    0b00000110, 0b10000110, 0b01000110, 0b11000110, 0b00100110, 0b10100110, 0b01100110, 0b11100110,
-    0b00010110, 0b10010110, 0b01010110, 0b11010110, 0b00110110, 0b10110110, 0b01110110, 0b11110110,
-    0b00001110, 0b10001110, 0b01001110, 0b11001110, 0b00101110, 0b10101110, 0b01101110, 0b11101110,
-    0b00011110, 0b10011110, 0b01011110, 0b11011110, 0b00111110, 0b10111110, 0b01111110, 0b11111110,
-    0b00000001, 0b10000001, 0b01000001, 0b11000001, 0b00100001, 0b10100001, 0b01100001, 0b11100001,
-    0b00010001, 0b10010001, 0b01010001, 0b11010001, 0b00110001, 0b10110001, 0b01110001, 0b11110001,
-    0b00001001, 0b10001001, 0b01001001, 0b11001001, 0b00101001, 0b10101001, 0b01101001, 0b11101001,
-    0b00011001, 0b10011001, 0b01011001, 0b11011001, 0b00111001, 0b10111001, 0b01111001, 0b11111001,
-    0b00000101, 0b10000101, 0b01000101, 0b11000101, 0b00100101, 0b10100101, 0b01100101, 0b11100101,
-    0b00010101, 0b10010101, 0b01010101, 0b11010101, 0b00110101, 0b10110101, 0b01110101, 0b11110101,
-    0b00001101, 0b10001101, 0b01001101, 0b11001101, 0b00101101, 0b10101101, 0b01101101, 0b11101101,
-    0b00011101, 0b10011101, 0b01011101, 0b11011101, 0b00111101, 0b10111101, 0b01111101, 0b11111101,
-    0b00010011, 0b00100110, 0b01001110, 0b10011010, 0b00111100, 0b01100101, 0b11101010, 0b10110100,
-    0b11101001, 0b00110011, 0b01100110, 0b11001110, 0b10011010, 0b00111101, 0b01100111, 0b11101110,
-    0b10111100, 0b11111001, 0b00001011, 0b00010110, 0b00101110, 0b01011010, 0b10111100, 0b01100100,
-    0b11101001, 0b10110010, 0b11100101, 0b00101011, 0b01010110, 0b10101110, 0b01011010, 0b10111101,
-    0b01100110, 0b11101101, 0b10111010, 0b11110101, 0b00011011, 0b00110110, 0b01101110, 0b11011010,
-    0b10111100, 0b01100101, 0b11101011, 0b10110110, 0b11101101, 0b00111011, 0b01110110, 0b11101110,
-    0b11011010, 0b10111101, 0b01100111, 0b11101111, 0b10111110, 0b11111101, 0b00000111, 0b00001110,
-    0b00011110, 0b00111010, 0b01111100, 0b11100100, 0b11101000, 0b10110001, 0b11100011, 0b00100111,
-    0b01001110, 0b10011110, 0b00111010, 0b01111101, 0b11100110, 0b11101100, 0b10111001, 0b11110011,
-    0b00010111, 0b00101110, 0b01011110, 0b10111010, 0b01111100, 0b11100101, 0b11101010, 0b10110101,
-    0b11101011, 0b00110111, 0b01101110, 0b11011110, 0b10111010, 0b01111101, 0b11100111, 0b11101110,
-    0b10111101, 0b11111011, 0b00001111, 0b00011110, 0b00111110, 0b01111010, 0b11111100, 0b11100100,
-    0b11101001, 0b10110011, 0b11100111, 0b00101111, 0b01011110, 0b10111110, 0b01111010, 0b11111101,
-    0b11100110, 0b11101101, 0b10111011, 0b11110111, 0b00011111, 0b00111110, 0b01111110, 0b11111010,
-    0b11111100, 0b11100101, 0b11101011, 0b10110111, 0b11101111, 0b00111111, 0b01111110, 0b11111110,
-    0b11111010, 0b11111101, 0b11100111, 0b11101111, 0b10111111, 0b11111111, 0b00000000, 0b00100000,
-    0b00001000, 0b00001100, 0b10000001, 0b11000010, 0b11100000, 0b00001000, 0b00100100, 0b00001010,
-    0b10001101, 0b11000001, 0b11100010, 0b11110000, 0b00000100, 0b00100010, 0b10001001, 0b01001100,
-    0b10100001, 0b11010010, 0b11101000, 0b00000011, 0b10000011, 0b01000011, 0b11000011, 0b00100011,
-    0b10100011,
-};
diff --git a/lib/std/compress/flate/inflate.zig b/lib/std/compress/flate/inflate.zig
deleted file mode 100644
index 2fcf3cafd4..0000000000
--- a/lib/std/compress/flate/inflate.zig
+++ /dev/null
@@ -1,570 +0,0 @@
-const std = @import("std");
-const assert = std.debug.assert;
-const testing = std.testing;
-
-const hfd = @import("huffman_decoder.zig");
-const BitReader = @import("bit_reader.zig").BitReader;
-const CircularBuffer = @import("CircularBuffer.zig");
-const Container = @import("container.zig").Container;
-const Token = @import("Token.zig");
-const codegen_order = @import("consts.zig").huffman.codegen_order;
-
-/// Decompresses deflate bit stream `reader` and writes uncompressed data to the
-/// `writer` stream.
-pub fn decompress(comptime container: Container, reader: anytype, writer: anytype) !void {
-    var d = decompressor(container, reader);
-    try d.decompress(writer);
-}
-
-/// Inflate decompressor for the reader type.
-pub fn decompressor(comptime container: Container, reader: anytype) Decompressor(container, @TypeOf(reader)) {
-    return Decompressor(container, @TypeOf(reader)).init(reader);
-}
-
-pub fn Decompressor(comptime container: Container, comptime ReaderType: type) type {
-    // zlib has 4 bytes footer, lookahead of 4 bytes ensures that we will not overshoot.
-    // gzip has 8 bytes footer so we will not overshoot even with 8 bytes of lookahead.
-    // For raw deflate there is always possibility of overshot so we use 8 bytes lookahead.
-    const lookahead: type = if (container == .zlib) u32 else u64;
-    return Inflate(container, lookahead, ReaderType);
-}
-
-/// Inflate decompresses deflate bit stream. Reads compressed data from reader
-/// provided in init. Decompressed data are stored in internal hist buffer and
-/// can be accesses iterable `next` or reader interface.
-///
-/// Container defines header/footer wrapper around deflate bit stream. Can be
-/// gzip or zlib.
-///
-/// Deflate bit stream consists of multiple blocks. Block can be one of three types:
-///   * stored, non compressed, max 64k in size
-///   * fixed, huffman codes are predefined
-///   * dynamic, huffman code tables are encoded at the block start
-///
-/// `step` function runs decoder until internal `hist` buffer is full. Client
-/// than needs to read that data in order to proceed with decoding.
-///
-/// Allocates 74.5K of internal buffers, most important are:
-///   * 64K for history (CircularBuffer)
-///   * ~10K huffman decoders (Literal and DistanceDecoder)
-///
-pub fn Inflate(comptime container: Container, comptime LookaheadType: type, comptime ReaderType: type) type {
-    assert(LookaheadType == u32 or LookaheadType == u64);
-    const BitReaderType = BitReader(LookaheadType, ReaderType);
-
-    return struct {
-        //const BitReaderType = BitReader(ReaderType);
-        const F = BitReaderType.flag;
-
-        bits: BitReaderType = .{},
-        hist: CircularBuffer = .{},
-        // Hashes, produces checkusm, of uncompressed data for gzip/zlib footer.
-        hasher: container.Hasher() = .{},
-
-        // dynamic block huffman code decoders
-        lit_dec: hfd.LiteralDecoder = .{}, // literals
-        dst_dec: hfd.DistanceDecoder = .{}, // distances
-
-        // current read state
-        bfinal: u1 = 0,
-        block_type: u2 = 0b11,
-        state: ReadState = .protocol_header,
-
-        const ReadState = enum {
-            protocol_header,
-            block_header,
-            block,
-            protocol_footer,
-            end,
-        };
-
-        const Self = @This();
-
-        pub const Error = BitReaderType.Error || Container.Error || hfd.Error || error{
-            InvalidCode,
-            InvalidMatch,
-            InvalidBlockType,
-            WrongStoredBlockNlen,
-            InvalidDynamicBlockHeader,
-        };
-
-        pub fn init(rt: ReaderType) Self {
-            return .{ .bits = BitReaderType.init(rt) };
-        }
-
-        fn blockHeader(self: *Self) !void {
-            self.bfinal = try self.bits.read(u1);
-            self.block_type = try self.bits.read(u2);
-        }
-
-        fn storedBlock(self: *Self) !bool {
-            self.bits.alignToByte(); // skip padding until byte boundary
-            // everything after this is byte aligned in stored block
-            var len = try self.bits.read(u16);
-            const nlen = try self.bits.read(u16);
-            if (len != ~nlen) return error.WrongStoredBlockNlen;
-
-            while (len > 0) {
-                const buf = self.hist.getWritable(len);
-                try self.bits.readAll(buf);
-                len -= @intCast(buf.len);
-            }
-            return true;
-        }
-
-        fn fixedBlock(self: *Self) !bool {
-            while (!self.hist.full()) {
-                const code = try self.bits.readFixedCode();
-                switch (code) {
-                    0...255 => self.hist.write(@intCast(code)),
-                    256 => return true, // end of block
-                    257...285 => try self.fixedDistanceCode(@intCast(code - 257)),
-                    else => return error.InvalidCode,
-                }
-            }
-            return false;
-        }
-
-        // Handles fixed block non literal (length) code.
-        // Length code is followed by 5 bits of distance code.
-        fn fixedDistanceCode(self: *Self, code: u8) !void {
-            try self.bits.fill(5 + 5 + 13);
-            const length = try self.decodeLength(code);
-            const distance = try self.decodeDistance(try self.bits.readF(u5, F.buffered | F.reverse));
-            try self.hist.writeMatch(length, distance);
-        }
-
-        inline fn decodeLength(self: *Self, code: u8) !u16 {
-            if (code > 28) return error.InvalidCode;
-            const ml = Token.matchLength(code);
-            return if (ml.extra_bits == 0) // 0 - 5 extra bits
-                ml.base
-            else
-                ml.base + try self.bits.readN(ml.extra_bits, F.buffered);
-        }
-
-        fn decodeDistance(self: *Self, code: u8) !u16 {
-            if (code > 29) return error.InvalidCode;
-            const md = Token.matchDistance(code);
-            return if (md.extra_bits == 0) // 0 - 13 extra bits
-                md.base
-            else
-                md.base + try self.bits.readN(md.extra_bits, F.buffered);
-        }
-
-        fn dynamicBlockHeader(self: *Self) !void {
-            const hlit: u16 = @as(u16, try self.bits.read(u5)) + 257; // number of ll code entries present - 257
-            const hdist: u16 = @as(u16, try self.bits.read(u5)) + 1; // number of distance code entries - 1
-            const hclen: u8 = @as(u8, try self.bits.read(u4)) + 4; // hclen + 4 code lengths are encoded
-
-            if (hlit > 286 or hdist > 30)
-                return error.InvalidDynamicBlockHeader;
-
-            // lengths for code lengths
-            var cl_lens = [_]u4{0} ** 19;
-            for (0..hclen) |i| {
-                cl_lens[codegen_order[i]] = try self.bits.read(u3);
-            }
-            var cl_dec: hfd.CodegenDecoder = .{};
-            try cl_dec.generate(&cl_lens);
-
-            // decoded code lengths
-            var dec_lens = [_]u4{0} ** (286 + 30);
-            var pos: usize = 0;
-            while (pos < hlit + hdist) {
-                const sym = try cl_dec.find(try self.bits.peekF(u7, F.reverse));
-                try self.bits.shift(sym.code_bits);
-                pos += try self.dynamicCodeLength(sym.symbol, &dec_lens, pos);
-            }
-            if (pos > hlit + hdist) {
-                return error.InvalidDynamicBlockHeader;
-            }
-
-            // literal code lengths to literal decoder
-            try self.lit_dec.generate(dec_lens[0..hlit]);
-
-            // distance code lengths to distance decoder
-            try self.dst_dec.generate(dec_lens[hlit .. hlit + hdist]);
-        }
-
-        // Decode code length symbol to code length. Writes decoded length into
-        // lens slice starting at position pos. Returns number of positions
-        // advanced.
-        fn dynamicCodeLength(self: *Self, code: u16, lens: []u4, pos: usize) !usize {
-            if (pos >= lens.len)
-                return error.InvalidDynamicBlockHeader;
-
-            switch (code) {
-                0...15 => {
-                    // Represent code lengths of 0 - 15
-                    lens[pos] = @intCast(code);
-                    return 1;
-                },
-                16 => {
-                    // Copy the previous code length 3 - 6 times.
-                    // The next 2 bits indicate repeat length
-                    const n: u8 = @as(u8, try self.bits.read(u2)) + 3;
-                    if (pos == 0 or pos + n > lens.len)
-                        return error.InvalidDynamicBlockHeader;
-                    for (0..n) |i| {
-                        lens[pos + i] = lens[pos + i - 1];
-                    }
-                    return n;
-                },
-                // Repeat a code length of 0 for 3 - 10 times. (3 bits of length)
-                17 => return @as(u8, try self.bits.read(u3)) + 3,
-                // Repeat a code length of 0 for 11 - 138 times (7 bits of length)
-                18 => return @as(u8, try self.bits.read(u7)) + 11,
-                else => return error.InvalidDynamicBlockHeader,
-            }
-        }
-
-        // In larger archives most blocks are usually dynamic, so decompression
-        // performance depends on this function.
-        fn dynamicBlock(self: *Self) !bool {
-            // Hot path loop!
-            while (!self.hist.full()) {
-                try self.bits.fill(15); // optimization so other bit reads can be buffered (avoiding one `if` in hot path)
-                const sym = try self.decodeSymbol(&self.lit_dec);
-
-                switch (sym.kind) {
-                    .literal => self.hist.write(sym.symbol),
-                    .match => { // Decode match backreference <length, distance>
-                        // fill so we can use buffered reads
-                        if (LookaheadType == u32)
-                            try self.bits.fill(5 + 15)
-                        else
-                            try self.bits.fill(5 + 15 + 13);
-                        const length = try self.decodeLength(sym.symbol);
-                        const dsm = try self.decodeSymbol(&self.dst_dec);
-                        if (LookaheadType == u32) try self.bits.fill(13);
-                        const distance = try self.decodeDistance(dsm.symbol);
-                        try self.hist.writeMatch(length, distance);
-                    },
-                    .end_of_block => return true,
-                }
-            }
-            return false;
-        }
-
-        // Peek 15 bits from bits reader (maximum code len is 15 bits). Use
-        // decoder to find symbol for that code. We then know how many bits is
-        // used. Shift bit reader for that much bits, those bits are used. And
-        // return symbol.
-        fn decodeSymbol(self: *Self, decoder: anytype) !hfd.Symbol {
-            const sym = try decoder.find(try self.bits.peekF(u15, F.buffered | F.reverse));
-            try self.bits.shift(sym.code_bits);
-            return sym;
-        }
-
-        fn step(self: *Self) !void {
-            switch (self.state) {
-                .protocol_header => {
-                    try container.parseHeader(&self.bits);
-                    self.state = .block_header;
-                },
-                .block_header => {
-                    try self.blockHeader();
-                    self.state = .block;
-                    if (self.block_type == 2) try self.dynamicBlockHeader();
-                },
-                .block => {
-                    const done = switch (self.block_type) {
-                        0 => try self.storedBlock(),
-                        1 => try self.fixedBlock(),
-                        2 => try self.dynamicBlock(),
-                        else => return error.InvalidBlockType,
-                    };
-                    if (done) {
-                        self.state = if (self.bfinal == 1) .protocol_footer else .block_header;
-                    }
-                },
-                .protocol_footer => {
-                    self.bits.alignToByte();
-                    try container.parseFooter(&self.hasher, &self.bits);
-                    self.state = .end;
-                },
-                .end => {},
-            }
-        }
-
-        /// Replaces the inner reader with new reader.
-        pub fn setReader(self: *Self, new_reader: ReaderType) void {
-            self.bits.forward_reader = new_reader;
-            if (self.state == .end or self.state == .protocol_footer) {
-                self.state = .protocol_header;
-            }
-        }
-
-        // Reads all compressed data from the internal reader and outputs plain
-        // (uncompressed) data to the provided writer.
-        pub fn decompress(self: *Self, writer: anytype) !void {
-            while (try self.next()) |buf| {
-                try writer.writeAll(buf);
-            }
-        }
-
-        /// Returns the number of bytes that have been read from the internal
-        /// reader but not yet consumed by the decompressor.
-        pub fn unreadBytes(self: Self) usize {
-            // There can be no error here: the denominator is not zero, and
-            // overflow is not possible since the type is unsigned.
-            return std.math.divCeil(usize, self.bits.nbits, 8) catch unreachable;
-        }
-
-        // Iterator interface
-
-        /// Can be used in iterator like loop without memcpy to another buffer:
-        ///   while (try inflate.next()) |buf| { ... }
-        pub fn next(self: *Self) Error!?[]const u8 {
-            const out = try self.get(0);
-            if (out.len == 0) return null;
-            return out;
-        }
-
-        /// Returns decompressed data from internal sliding window buffer.
-        /// Returned buffer can be any length between 0 and `limit` bytes. 0
-        /// returned bytes means end of stream reached. With limit=0 returns as
-        /// much data it can. It newer will be more than 65536 bytes, which is
-        /// size of internal buffer.
-        pub fn get(self: *Self, limit: usize) Error![]const u8 {
-            while (true) {
-                const out = self.hist.readAtMost(limit);
-                if (out.len > 0) {
-                    self.hasher.update(out);
-                    return out;
-                }
-                if (self.state == .end) return out;
-                try self.step();
-            }
-        }
-
-        // Reader interface
-
-        pub const Reader = std.io.GenericReader(*Self, Error, read);
-
-        /// Returns the number of bytes read. It may be less than buffer.len.
-        /// If the number of bytes read is 0, it means end of stream.
-        /// End of stream is not an error condition.
-        pub fn read(self: *Self, buffer: []u8) Error!usize {
-            if (buffer.len == 0) return 0;
-            const out = try self.get(buffer.len);
-            @memcpy(buffer[0..out.len], out);
-            return out.len;
-        }
-
-        pub fn reader(self: *Self) Reader {
-            return .{ .context = self };
-        }
-    };
-}
-
-test "decompress" {
-    const cases = [_]struct {
-        in: []const u8,
-        out: []const u8,
-    }{
-        // non compressed block (type 0)
-        .{
-            .in = &[_]u8{
-                0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
-                'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
-            },
-            .out = "Hello world\n",
-        },
-        // fixed code block (type 1)
-        .{
-            .in = &[_]u8{
-                0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, // deflate data block type 1
-                0x2f, 0xca, 0x49, 0xe1, 0x02, 0x00,
-            },
-            .out = "Hello world\n",
-        },
-        // dynamic block (type 2)
-        .{
-            .in = &[_]u8{
-                0x3d, 0xc6, 0x39, 0x11, 0x00, 0x00, 0x0c, 0x02, // deflate data block type 2
-                0x30, 0x2b, 0xb5, 0x52, 0x1e, 0xff, 0x96, 0x38,
-                0x16, 0x96, 0x5c, 0x1e, 0x94, 0xcb, 0x6d, 0x01,
-            },
-            .out = "ABCDEABCD ABCDEABCD",
-        },
-    };
-    for (cases) |c| {
-        var fb = std.io.fixedBufferStream(c.in);
-        var al = std.ArrayList(u8).init(testing.allocator);
-        defer al.deinit();
-
-        try decompress(.raw, fb.reader(), al.writer());
-        try testing.expectEqualStrings(c.out, al.items);
-    }
-}
-
-test "gzip decompress" {
-    const cases = [_]struct {
-        in: []const u8,
-        out: []const u8,
-    }{
-        // non compressed block (type 0)
-        .{
-            .in = &[_]u8{
-                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, // gzip header (10 bytes)
-                0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
-                'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
-                0xd5, 0xe0, 0x39, 0xb7, // gzip footer: checksum
-                0x0c, 0x00, 0x00, 0x00, // gzip footer: size
-            },
-            .out = "Hello world\n",
-        },
-        // fixed code block (type 1)
-        .{
-            .in = &[_]u8{
-                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x03, // gzip header (10 bytes)
-                0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, // deflate data block type 1
-                0x2f, 0xca, 0x49, 0xe1, 0x02, 0x00,
-                0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00, // gzip footer (chksum, len)
-            },
-            .out = "Hello world\n",
-        },
-        // dynamic block (type 2)
-        .{
-            .in = &[_]u8{
-                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, // gzip header (10 bytes)
-                0x3d, 0xc6, 0x39, 0x11, 0x00, 0x00, 0x0c, 0x02, // deflate data block type 2
-                0x30, 0x2b, 0xb5, 0x52, 0x1e, 0xff, 0x96, 0x38,
-                0x16, 0x96, 0x5c, 0x1e, 0x94, 0xcb, 0x6d, 0x01,
-                0x17, 0x1c, 0x39, 0xb4, 0x13, 0x00, 0x00, 0x00, // gzip footer (chksum, len)
-            },
-            .out = "ABCDEABCD ABCDEABCD",
-        },
-        // gzip header with name
-        .{
-            .in = &[_]u8{
-                0x1f, 0x8b, 0x08, 0x08, 0xe5, 0x70, 0xb1, 0x65, 0x00, 0x03, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e,
-                0x74, 0x78, 0x74, 0x00, 0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x28, 0xcf, 0x2f, 0xca, 0x49, 0xe1,
-                0x02, 0x00, 0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00,
-            },
-            .out = "Hello world\n",
-        },
-    };
-    for (cases) |c| {
-        var fb = std.io.fixedBufferStream(c.in);
-        var al = std.ArrayList(u8).init(testing.allocator);
-        defer al.deinit();
-
-        try decompress(.gzip, fb.reader(), al.writer());
-        try testing.expectEqualStrings(c.out, al.items);
-    }
-}
-
-test "zlib decompress" {
-    const cases = [_]struct {
-        in: []const u8,
-        out: []const u8,
-    }{
-        // non compressed block (type 0)
-        .{
-            .in = &[_]u8{
-                0x78, 0b10_0_11100, // zlib header (2 bytes)
-                0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
-                'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
-                0x1c, 0xf2, 0x04, 0x47, // zlib footer: checksum
-            },
-            .out = "Hello world\n",
-        },
-    };
-    for (cases) |c| {
-        var fb = std.io.fixedBufferStream(c.in);
-        var al = std.ArrayList(u8).init(testing.allocator);
-        defer al.deinit();
-
-        try decompress(.zlib, fb.reader(), al.writer());
-        try testing.expectEqualStrings(c.out, al.items);
-    }
-}
-
-test "fuzzing tests" {
-    const cases = [_]struct {
-        input: []const u8,
-        out: []const u8 = "",
-        err: ?anyerror = null,
-    }{
-        .{ .input = "deflate-stream", .out = @embedFile("testdata/fuzz/deflate-stream.expect") }, // 0
-        .{ .input = "empty-distance-alphabet01" },
-        .{ .input = "empty-distance-alphabet02" },
-        .{ .input = "end-of-stream", .err = error.EndOfStream },
-        .{ .input = "invalid-distance", .err = error.InvalidMatch },
-        .{ .input = "invalid-tree01", .err = error.IncompleteHuffmanTree }, // 5
-        .{ .input = "invalid-tree02", .err = error.IncompleteHuffmanTree },
-        .{ .input = "invalid-tree03", .err = error.IncompleteHuffmanTree },
-        .{ .input = "lengths-overflow", .err = error.InvalidDynamicBlockHeader },
-        .{ .input = "out-of-codes", .err = error.InvalidCode },
-        .{ .input = "puff01", .err = error.WrongStoredBlockNlen }, // 10
-        .{ .input = "puff02", .err = error.EndOfStream },
-        .{ .input = "puff03", .out = &[_]u8{0xa} },
-        .{ .input = "puff04", .err = error.InvalidCode },
-        .{ .input = "puff05", .err = error.EndOfStream },
-        .{ .input = "puff06", .err = error.EndOfStream },
-        .{ .input = "puff08", .err = error.InvalidCode },
-        .{ .input = "puff09", .out = "P" },
-        .{ .input = "puff10", .err = error.InvalidCode },
-        .{ .input = "puff11", .err = error.InvalidMatch },
-        .{ .input = "puff12", .err = error.InvalidDynamicBlockHeader }, // 20
-        .{ .input = "puff13", .err = error.IncompleteHuffmanTree },
-        .{ .input = "puff14", .err = error.EndOfStream },
-        .{ .input = "puff15", .err = error.IncompleteHuffmanTree },
-        .{ .input = "puff16", .err = error.InvalidDynamicBlockHeader },
-        .{ .input = "puff17", .err = error.MissingEndOfBlockCode }, // 25
-        .{ .input = "fuzz1", .err = error.InvalidDynamicBlockHeader },
-        .{ .input = "fuzz2", .err = error.InvalidDynamicBlockHeader },
-        .{ .input = "fuzz3", .err = error.InvalidMatch },
-        .{ .input = "fuzz4", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff18", .err = error.OversubscribedHuffmanTree }, // 30
-        .{ .input = "puff19", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff20", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff21", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff22", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff23", .err = error.OversubscribedHuffmanTree }, // 35
-        .{ .input = "puff24", .err = error.IncompleteHuffmanTree },
-        .{ .input = "puff25", .err = error.OversubscribedHuffmanTree },
-        .{ .input = "puff26", .err = error.InvalidDynamicBlockHeader },
-        .{ .input = "puff27", .err = error.InvalidDynamicBlockHeader },
-    };
-
-    inline for (cases, 0..) |c, case_no| {
-        var in = std.io.fixedBufferStream(@embedFile("testdata/fuzz/" ++ c.input ++ ".input"));
-        var out = std.ArrayList(u8).init(testing.allocator);
-        defer out.deinit();
-        errdefer std.debug.print("test case failed {}\n", .{case_no});
-
-        if (c.err) |expected_err| {
-            try testing.expectError(expected_err, decompress(.raw, in.reader(), out.writer()));
-        } else {
-            try decompress(.raw, in.reader(), out.writer());
-            try testing.expectEqualStrings(c.out, out.items);
-        }
-    }
-}
-
-test "bug 18966" {
-    const input = @embedFile("testdata/fuzz/bug_18966.input");
-    const expect = @embedFile("testdata/fuzz/bug_18966.expect");
-
-    var in = std.io.fixedBufferStream(input);
-    var out = std.ArrayList(u8).init(testing.allocator);
-    defer out.deinit();
-
-    try decompress(.gzip, in.reader(), out.writer());
-    try testing.expectEqualStrings(expect, out.items);
-}
-
-test "bug 19895" {
-    const input = &[_]u8{
-        0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen
-        'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a, // non compressed data
-    };
-    var in = std.io.fixedBufferStream(input);
-    var decomp = decompressor(.raw, in.reader());
-    var buf: [0]u8 = undefined;
-    try testing.expectEqual(0, try decomp.read(&buf));
-}
diff --git a/lib/std/compress/flate/testdata/block_writer.zig b/lib/std/compress/flate/testdata/block_writer.zig
deleted file mode 100644
index cb8f3028d1..0000000000
--- a/lib/std/compress/flate/testdata/block_writer.zig
+++ /dev/null
@@ -1,606 +0,0 @@
-const Token = @import("../Token.zig");
-
-pub const TestCase = struct {
-    tokens: []const Token,
-    input: []const u8 = "", // File name of input data matching the tokens.
-    want: []const u8 = "", // File name of data with the expected output with input available.
-    want_no_input: []const u8 = "", // File name of the expected output when no input is available.
-};
-
-pub const testCases = blk: {
-    @setEvalBranchQuota(4096 * 2);
-
-    const L = Token.initLiteral;
-    const M = Token.initMatch;
-    const ml = M(1, 258); // Maximum length token. Used to reduce the size of writeBlockTests
-
-    break :blk &[_]TestCase{
-        TestCase{
-            .input = "huffman-null-max.input",
-            .want = "huffman-null-max.{s}.expect",
-            .want_no_input = "huffman-null-max.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L(0x0), ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,     ml,     ml, ml, ml,
-                ml,     ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, L(0x0), L(0x0),
-            },
-        },
-        TestCase{
-            .input = "huffman-pi.input",
-            .want = "huffman-pi.{s}.expect",
-            .want_no_input = "huffman-pi.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L('3'),     L('.'),     L('1'),     L('4'),     L('1'),     L('5'),     L('9'),     L('2'),
-                L('6'),     L('5'),     L('3'),     L('5'),     L('8'),     L('9'),     L('7'),     L('9'),
-                L('3'),     L('2'),     L('3'),     L('8'),     L('4'),     L('6'),     L('2'),     L('6'),
-                L('4'),     L('3'),     L('3'),     L('8'),     L('3'),     L('2'),     L('7'),     L('9'),
-                L('5'),     L('0'),     L('2'),     L('8'),     L('8'),     L('4'),     L('1'),     L('9'),
-                L('7'),     L('1'),     L('6'),     L('9'),     L('3'),     L('9'),     L('9'),     L('3'),
-                L('7'),     L('5'),     L('1'),     L('0'),     L('5'),     L('8'),     L('2'),     L('0'),
-                L('9'),     L('7'),     L('4'),     L('9'),     L('4'),     L('4'),     L('5'),     L('9'),
-                L('2'),     L('3'),     L('0'),     L('7'),     L('8'),     L('1'),     L('6'),     L('4'),
-                L('0'),     L('6'),     L('2'),     L('8'),     L('6'),     L('2'),     L('0'),     L('8'),
-                L('9'),     L('9'),     L('8'),     L('6'),     L('2'),     L('8'),     L('0'),     L('3'),
-                L('4'),     L('8'),     L('2'),     L('5'),     L('3'),     L('4'),     L('2'),     L('1'),
-                L('1'),     L('7'),     L('0'),     L('6'),     L('7'),     L('9'),     L('8'),     L('2'),
-                L('1'),     L('4'),     L('8'),     L('0'),     L('8'),     L('6'),     L('5'),     L('1'),
-                L('3'),     L('2'),     L('8'),     L('2'),     L('3'),     L('0'),     L('6'),     L('6'),
-                L('4'),     L('7'),     L('0'),     L('9'),     L('3'),     L('8'),     L('4'),     L('4'),
-                L('6'),     L('0'),     L('9'),     L('5'),     L('5'),     L('0'),     L('5'),     L('8'),
-                L('2'),     L('2'),     L('3'),     L('1'),     L('7'),     L('2'),     L('5'),     L('3'),
-                L('5'),     L('9'),     L('4'),     L('0'),     L('8'),     L('1'),     L('2'),     L('8'),
-                L('4'),     L('8'),     L('1'),     L('1'),     L('1'),     L('7'),     L('4'),     M(127, 4),
-                L('4'),     L('1'),     L('0'),     L('2'),     L('7'),     L('0'),     L('1'),     L('9'),
-                L('3'),     L('8'),     L('5'),     L('2'),     L('1'),     L('1'),     L('0'),     L('5'),
-                L('5'),     L('5'),     L('9'),     L('6'),     L('4'),     L('4'),     L('6'),     L('2'),
-                L('2'),     L('9'),     L('4'),     L('8'),     L('9'),     L('5'),     L('4'),     L('9'),
-                L('3'),     L('0'),     L('3'),     L('8'),     L('1'),     M(19, 4),   L('2'),     L('8'),
-                L('8'),     L('1'),     L('0'),     L('9'),     L('7'),     L('5'),     L('6'),     L('6'),
-                L('5'),     L('9'),     L('3'),     L('3'),     L('4'),     L('4'),     L('6'),     M(72, 4),
-                L('7'),     L('5'),     L('6'),     L('4'),     L('8'),     L('2'),     L('3'),     L('3'),
-                L('7'),     L('8'),     L('6'),     L('7'),     L('8'),     L('3'),     L('1'),     L('6'),
-                L('5'),     L('2'),     L('7'),     L('1'),     L('2'),     L('0'),     L('1'),     L('9'),
-                L('0'),     L('9'),     L('1'),     L('4'),     M(27, 4),   L('5'),     L('6'),     L('6'),
-                L('9'),     L('2'),     L('3'),     L('4'),     L('6'),     M(179, 4),  L('6'),     L('1'),
-                L('0'),     L('4'),     L('5'),     L('4'),     L('3'),     L('2'),     L('6'),     M(51, 4),
-                L('1'),     L('3'),     L('3'),     L('9'),     L('3'),     L('6'),     L('0'),     L('7'),
-                L('2'),     L('6'),     L('0'),     L('2'),     L('4'),     L('9'),     L('1'),     L('4'),
-                L('1'),     L('2'),     L('7'),     L('3'),     L('7'),     L('2'),     L('4'),     L('5'),
-                L('8'),     L('7'),     L('0'),     L('0'),     L('6'),     L('6'),     L('0'),     L('6'),
-                L('3'),     L('1'),     L('5'),     L('5'),     L('8'),     L('8'),     L('1'),     L('7'),
-                L('4'),     L('8'),     L('8'),     L('1'),     L('5'),     L('2'),     L('0'),     L('9'),
-                L('2'),     L('0'),     L('9'),     L('6'),     L('2'),     L('8'),     L('2'),     L('9'),
-                L('2'),     L('5'),     L('4'),     L('0'),     L('9'),     L('1'),     L('7'),     L('1'),
-                L('5'),     L('3'),     L('6'),     L('4'),     L('3'),     L('6'),     L('7'),     L('8'),
-                L('9'),     L('2'),     L('5'),     L('9'),     L('0'),     L('3'),     L('6'),     L('0'),
-                L('0'),     L('1'),     L('1'),     L('3'),     L('3'),     L('0'),     L('5'),     L('3'),
-                L('0'),     L('5'),     L('4'),     L('8'),     L('8'),     L('2'),     L('0'),     L('4'),
-                L('6'),     L('6'),     L('5'),     L('2'),     L('1'),     L('3'),     L('8'),     L('4'),
-                L('1'),     L('4'),     L('6'),     L('9'),     L('5'),     L('1'),     L('9'),     L('4'),
-                L('1'),     L('5'),     L('1'),     L('1'),     L('6'),     L('0'),     L('9'),     L('4'),
-                L('3'),     L('3'),     L('0'),     L('5'),     L('7'),     L('2'),     L('7'),     L('0'),
-                L('3'),     L('6'),     L('5'),     L('7'),     L('5'),     L('9'),     L('5'),     L('9'),
-                L('1'),     L('9'),     L('5'),     L('3'),     L('0'),     L('9'),     L('2'),     L('1'),
-                L('8'),     L('6'),     L('1'),     L('1'),     L('7'),     M(234, 4),  L('3'),     L('2'),
-                M(10, 4),   L('9'),     L('3'),     L('1'),     L('0'),     L('5'),     L('1'),     L('1'),
-                L('8'),     L('5'),     L('4'),     L('8'),     L('0'),     L('7'),     M(271, 4),  L('3'),
-                L('7'),     L('9'),     L('9'),     L('6'),     L('2'),     L('7'),     L('4'),     L('9'),
-                L('5'),     L('6'),     L('7'),     L('3'),     L('5'),     L('1'),     L('8'),     L('8'),
-                L('5'),     L('7'),     L('5'),     L('2'),     L('7'),     L('2'),     L('4'),     L('8'),
-                L('9'),     L('1'),     L('2'),     L('2'),     L('7'),     L('9'),     L('3'),     L('8'),
-                L('1'),     L('8'),     L('3'),     L('0'),     L('1'),     L('1'),     L('9'),     L('4'),
-                L('9'),     L('1'),     L('2'),     L('9'),     L('8'),     L('3'),     L('3'),     L('6'),
-                L('7'),     L('3'),     L('3'),     L('6'),     L('2'),     L('4'),     L('4'),     L('0'),
-                L('6'),     L('5'),     L('6'),     L('6'),     L('4'),     L('3'),     L('0'),     L('8'),
-                L('6'),     L('0'),     L('2'),     L('1'),     L('3'),     L('9'),     L('4'),     L('9'),
-                L('4'),     L('6'),     L('3'),     L('9'),     L('5'),     L('2'),     L('2'),     L('4'),
-                L('7'),     L('3'),     L('7'),     L('1'),     L('9'),     L('0'),     L('7'),     L('0'),
-                L('2'),     L('1'),     L('7'),     L('9'),     L('8'),     M(154, 5),  L('7'),     L('0'),
-                L('2'),     L('7'),     L('7'),     L('0'),     L('5'),     L('3'),     L('9'),     L('2'),
-                L('1'),     L('7'),     L('1'),     L('7'),     L('6'),     L('2'),     L('9'),     L('3'),
-                L('1'),     L('7'),     L('6'),     L('7'),     L('5'),     M(563, 5),  L('7'),     L('4'),
-                L('8'),     L('1'),     M(7, 4),    L('6'),     L('6'),     L('9'),     L('4'),     L('0'),
-                M(488, 4),  L('0'),     L('0'),     L('0'),     L('5'),     L('6'),     L('8'),     L('1'),
-                L('2'),     L('7'),     L('1'),     L('4'),     L('5'),     L('2'),     L('6'),     L('3'),
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-                L('6'),     L('5'),     M(309, 4),  L('8'),     L('1'),     M(93, 4),   M(1862, 4), M(2359, 4),
-                L('6'),     L('8'),     L('2'),     L('9'),     M(1407, 4), L('8'),     L('7'),     L('2'),
-                L('2'),     L('6'),     L('5'),     L('8'),     L('8'),     L('0'),     M(1554, 4), L('5'),
-                M(586, 4),  L('4'),     L('2'),     L('7'),     L('0'),     L('4'),     L('7'),     L('7'),
-                L('5'),     L('5'),     M(2079, 4), L('3'),     L('7'),     L('9'),     L('6'),     L('4'),
-                L('1'),     L('4'),     L('5'),     L('1'),     L('5'),     L('2'),     M(1534, 4), L('2'),
-                L('3'),     L('4'),     L('3'),     L('6'),     L('4'),     L('5'),     L('4'),     M(1503, 4),
-                L('4'),     L('4'),     L('4'),     L('7'),     L('9'),     L('5'),     M(61, 4),   M(1316, 4),
-                M(2279, 5), L('4'),     L('1'),     M(1323, 4), L('3'),     M(773, 4),  L('5'),     L('2'),
-                L('3'),     L('1'),     M(2114, 5), L('1'),     L('6'),     L('6'),     L('1'),     M(2227, 4),
-                L('5'),     L('9'),     L('6'),     L('9'),     L('5'),     L('3'),     L('6'),     L('2'),
-                L('3'),     L('1'),     L('4'),     M(1536, 4), L('2'),     L('4'),     L('8'),     L('4'),
-                L('9'),     L('3'),     L('7'),     L('1'),     L('8'),     L('7'),     L('1'),     L('1'),
-                L('0'),     L('1'),     L('4'),     L('5'),     L('7'),     L('6'),     L('5'),     L('4'),
-                M(1890, 4), L('0'),     L('2'),     L('7'),     L('9'),     L('9'),     L('3'),     L('4'),
-                L('4'),     L('0'),     L('3'),     L('7'),     L('4'),     L('2'),     L('0'),     L('0'),
-                L('7'),     M(2368, 4), L('7'),     L('8'),     L('5'),     L('3'),     L('9'),     L('0'),
-                L('6'),     L('2'),     L('1'),     L('9'),     M(666, 5),  M(838, 4),  L('8'),     L('4'),
-                L('7'),     M(979, 5),  L('8'),     L('3'),     L('3'),     L('2'),     L('1'),     L('4'),
-                L('4'),     L('5'),     L('7'),     L('1'),     M(645, 4),  M(1911, 4), L('4'),     L('3'),
-                L('5'),     L('0'),     M(2345, 4), M(1129, 4), L('5'),     L('3'),     L('1'),     L('9'),
-                L('1'),     L('0'),     L('4'),     L('8'),     L('4'),     L('8'),     L('1'),     L('0'),
-                L('0'),     L('5'),     L('3'),     L('7'),     L('0'),     L('6'),     M(2237, 4), M(1438, 5),
-                M(1922, 5), L('1'),     M(1370, 4), L('7'),     M(796, 4),  L('5'),     M(2029, 4), M(1037, 4),
-                L('6'),     L('3'),     M(2013, 5), L('4'),     M(2418, 4), M(847, 5),  M(1014, 5), L('8'),
-                M(1326, 5), M(2184, 5), L('9'),     M(392, 4),  L('9'),     L('1'),     M(2255, 4), L('8'),
-                L('1'),     L('4'),     L('6'),     L('7'),     L('5'),     L('1'),     M(1580, 4), L('1'),
-                L('2'),     L('3'),     L('9'),     M(426, 6),  L('9'),     L('0'),     L('7'),     L('1'),
-                L('8'),     L('6'),     L('4'),     L('9'),     L('4'),     L('2'),     L('3'),     L('1'),
-                L('9'),     L('6'),     L('1'),     L('5'),     L('6'),     M(493, 4),  M(1725, 4), L('9'),
-                L('5'),     M(2343, 4), M(1130, 4), M(284, 4),  L('6'),     L('0'),     L('3'),     L('8'),
-                M(2598, 4), M(368, 4),  M(901, 4),  L('6'),     L('2'),     M(1115, 4), L('5'),     M(2125, 4),
-                L('6'),     L('3'),     L('8'),     L('9'),     L('3'),     L('7'),     L('7'),     L('8'),
-                L('7'),     M(2246, 4), M(249, 4),  L('9'),     L('7'),     L('9'),     L('2'),     L('0'),
-                L('7'),     L('7'),     L('3'),     M(1496, 4), L('2'),     L('1'),     L('8'),     L('2'),
-                L('5'),     L('6'),     M(2016, 4), L('6'),     L('6'),     M(1751, 4), L('4'),     L('2'),
-                M(1663, 5), L('6'),     M(1767, 4), L('4'),     L('4'),     M(37, 4),   L('5'),     L('4'),
-                L('9'),     L('2'),     L('0'),     L('2'),     L('6'),     L('0'),     L('5'),     M(2740, 4),
-                M(997, 5),  L('2'),     L('0'),     L('1'),     L('4'),     L('9'),     M(1235, 4), L('8'),
-                L('5'),     L('0'),     L('7'),     L('3'),     M(1434, 4), L('6'),     L('6'),     L('6'),
-                L('0'),     M(405, 4),  L('2'),     L('4'),     L('3'),     L('4'),     L('0'),     M(136, 4),
-                L('0'),     M(1900, 4), L('8'),     L('6'),     L('3'),     M(2391, 4), M(2021, 4), M(1068, 4),
-                M(373, 4),  L('5'),     L('7'),     L('9'),     L('6'),     L('2'),     L('6'),     L('8'),
-                L('5'),     L('6'),     M(321, 4),  L('5'),     L('0'),     L('8'),     M(1316, 4), L('5'),
-                L('8'),     L('7'),     L('9'),     L('6'),     L('9'),     L('9'),     M(1810, 4), L('5'),
-                L('7'),     L('4'),     M(2585, 4), L('8'),     L('4'),     L('0'),     M(2228, 4), L('1'),
-                L('4'),     L('5'),     L('9'),     L('1'),     M(1933, 4), L('7'),     L('0'),     M(565, 4),
-                L('0'),     L('1'),     M(3048, 4), L('1'),     L('2'),     M(3189, 4), L('0'),     M(964, 4),
-                L('3'),     L('9'),     M(2859, 4), M(275, 4),  L('7'),     L('1'),     L('5'),     M(945, 4),
-                L('4'),     L('2'),     L('0'),     M(3059, 5), L('9'),     M(3011, 4), L('0'),     L('7'),
-                M(834, 4),  M(1942, 4), M(2736, 4), M(3171, 4), L('2'),     L('1'),     M(2401, 4), L('2'),
-                L('5'),     L('1'),     M(1404, 4), M(2373, 4), L('9'),     L('2'),     M(435, 4),  L('8'),
-                L('2'),     L('6'),     M(2919, 4), L('2'),     M(633, 4),  L('3'),     L('2'),     L('1'),
-                L('5'),     L('7'),     L('9'),     L('1'),     L('9'),     L('8'),     L('4'),     L('1'),
-                L('4'),     M(2172, 5), L('9'),     L('1'),     L('6'),     L('4'),     M(1769, 5), L('9'),
-                M(2905, 5), M(2268, 4), L('7'),     L('2'),     L('2'),     M(802, 4),  L('5'),     M(2213, 4),
-                M(322, 4),  L('9'),     L('1'),     L('0'),     M(189, 4),  M(3164, 4), L('5'),     L('2'),
-                L('8'),     L('0'),     L('1'),     L('7'),     M(562, 4),  L('7'),     L('1'),     L('2'),
-                M(2325, 4), L('8'),     L('3'),     L('2'),     M(884, 4),  L('1'),     M(1418, 4), L('0'),
-                L('9'),     L('3'),     L('5'),     L('3'),     L('9'),     L('6'),     L('5'),     L('7'),
-                M(1612, 4), L('1'),     L('0'),     L('8'),     L('3'),     M(106, 4),  L('5'),     L('1'),
-                M(1915, 4), M(3419, 4), L('1'),     L('4'),     L('4'),     L('4'),     L('2'),     L('1'),
-                L('0'),     L('0'),     M(515, 4),  L('0'),     L('3'),     M(413, 4),  L('1'),     L('1'),
-                L('0'),     L('3'),     M(3202, 4), M(10, 4),   M(39, 4),   M(1539, 6), L('5'),     L('1'),
-                L('6'),     M(1498, 4), M(2180, 5), M(2347, 4), L('5'),     M(3139, 5), L('8'),     L('5'),
-                L('1'),     L('7'),     L('1'),     L('4'),     L('3'),     L('7'),     M(1542, 4), M(110, 4),
-                L('1'),     L('5'),     L('5'),     L('6'),     L('5'),     L('0'),     L('8'),     L('8'),
-                M(954, 4),  L('9'),     L('8'),     L('9'),     L('8'),     L('5'),     L('9'),     L('9'),
-                L('8'),     L('2'),     L('3'),     L('8'),     M(464, 4),  M(2491, 4), L('3'),     M(365, 4),
-                M(1087, 4), M(2500, 4), L('8'),     M(3590, 5), L('3'),     L('2'),     M(264, 4),  L('5'),
-                M(774, 4),  L('3'),     M(459, 4),  L('9'),     M(1052, 4), L('9'),     L('8'),     M(2174, 4),
-                L('4'),     M(3257, 4), L('7'),     M(1612, 4), L('0'),     L('7'),     M(230, 4),  L('4'),
-                L('8'),     L('1'),     L('4'),     L('1'),     M(1338, 4), L('8'),     L('5'),     L('9'),
-                L('4'),     L('6'),     L('1'),     M(3018, 4), L('8'),     L('0'),
-            },
-        },
-        TestCase{
-            .input = "huffman-rand-1k.input",
-            .want = "huffman-rand-1k.{s}.expect",
-            .want_no_input = "huffman-rand-1k.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L(0xf8), L(0x8b), L(0x96), L(0x76), L(0x48), L(0xd),  L(0x85), L(0x94), L(0x25), L(0x80), L(0xaf), L(0xc2), L(0xfe), L(0x8d),
-                L(0xe8), L(0x20), L(0xeb), L(0x17), L(0x86), L(0xc9), L(0xb7), L(0xc5), L(0xde), L(0x6),  L(0xea), L(0x7d), L(0x18), L(0x8b),
-                L(0xe7), L(0x3e), L(0x7),  L(0xda), L(0xdf), L(0xff), L(0x6c), L(0x73), L(0xde), L(0xcc), L(0xe7), L(0x6d), L(0x8d), L(0x4),
-                L(0x19), L(0x49), L(0x7f), L(0x47), L(0x1f), L(0x48), L(0x15), L(0xb0), L(0xe8), L(0x9e), L(0xf2), L(0x31), L(0x59), L(0xde),
-                L(0x34), L(0xb4), L(0x5b), L(0xe5), L(0xe0), L(0x9),  L(0x11), L(0x30), L(0xc2), L(0x88), L(0x5b), L(0x7c), L(0x5d), L(0x14),
-                L(0x13), L(0x6f), L(0x23), L(0xa9), L(0xd),  L(0xbc), L(0x2d), L(0x23), L(0xbe), L(0xd9), L(0xed), L(0x75), L(0x4),  L(0x6c),
-                L(0x99), L(0xdf), L(0xfd), L(0x70), L(0x66), L(0xe6), L(0xee), L(0xd9), L(0xb1), L(0x9e), L(0x6e), L(0x83), L(0x59), L(0xd5),
-                L(0xd4), L(0x80), L(0x59), L(0x98), L(0x77), L(0x89), L(0x43), L(0x38), L(0xc9), L(0xaf), L(0x30), L(0x32), L(0x9a), L(0x20),
-                L(0x1b), L(0x46), L(0x3d), L(0x67), L(0x6e), L(0xd7), L(0x72), L(0x9e), L(0x4e), L(0x21), L(0x4f), L(0xc6), L(0xe0), L(0xd4),
-                L(0x7b), L(0x4),  L(0x8d), L(0xa5), L(0x3),  L(0xf6), L(0x5),  L(0x9b), L(0x6b), L(0xdc), L(0x2a), L(0x93), L(0x77), L(0x28),
-                L(0xfd), L(0xb4), L(0x62), L(0xda), L(0x20), L(0xe7), L(0x1f), L(0xab), L(0x6b), L(0x51), L(0x43), L(0x39), L(0x2f), L(0xa0),
-                L(0x92), L(0x1),  L(0x6c), L(0x75), L(0x3e), L(0xf4), L(0x35), L(0xfd), L(0x43), L(0x2e), L(0xf7), L(0xa4), L(0x75), L(0xda),
-                L(0xea), L(0x9b), L(0xa),  L(0x64), L(0xb),  L(0xe0), L(0x23), L(0x29), L(0xbd), L(0xf7), L(0xe7), L(0x83), L(0x3c), L(0xfb),
-                L(0xdf), L(0xb3), L(0xae), L(0x4f), L(0xa4), L(0x47), L(0x55), L(0x99), L(0xde), L(0x2f), L(0x96), L(0x6e), L(0x1c), L(0x43),
-                L(0x4c), L(0x87), L(0xe2), L(0x7c), L(0xd9), L(0x5f), L(0x4c), L(0x7c), L(0xe8), L(0x90), L(0x3),  L(0xdb), L(0x30), L(0x95),
-                L(0xd6), L(0x22), L(0xc),  L(0x47), L(0xb8), L(0x4d), L(0x6b), L(0xbd), L(0x24), L(0x11), L(0xab), L(0x2c), L(0xd7), L(0xbe),
-                L(0x6e), L(0x7a), L(0xd6), L(0x8),  L(0xa3), L(0x98), L(0xd8), L(0xdd), L(0x15), L(0x6a), L(0xfa), L(0x93), L(0x30), L(0x1),
-                L(0x25), L(0x1d), L(0xa2), L(0x74), L(0x86), L(0x4b), L(0x6a), L(0x95), L(0xe8), L(0xe1), L(0x4e), L(0xe),  L(0x76), L(0xb9),
-                L(0x49), L(0xa9), L(0x5f), L(0xa0), L(0xa6), L(0x63), L(0x3c), L(0x7e), L(0x7e), L(0x20), L(0x13), L(0x4f), L(0xbb), L(0x66),
-                L(0x92), L(0xb8), L(0x2e), L(0xa4), L(0xfa), L(0x48), L(0xcb), L(0xae), L(0xb9), L(0x3c), L(0xaf), L(0xd3), L(0x1f), L(0xe1),
-                L(0xd5), L(0x8d), L(0x42), L(0x6d), L(0xf0), L(0xfc), L(0x8c), L(0xc),  L(0x0),  L(0xde), L(0x40), L(0xab), L(0x8b), L(0x47),
-                L(0x97), L(0x4e), L(0xa8), L(0xcf), L(0x8e), L(0xdb), L(0xa6), L(0x8b), L(0x20), L(0x9),  L(0x84), L(0x7a), L(0x66), L(0xe5),
-                L(0x98), L(0x29), L(0x2),  L(0x95), L(0xe6), L(0x38), L(0x32), L(0x60), L(0x3),  L(0xe3), L(0x9a), L(0x1e), L(0x54), L(0xe8),
-                L(0x63), L(0x80), L(0x48), L(0x9c), L(0xe7), L(0x63), L(0x33), L(0x6e), L(0xa0), L(0x65), L(0x83), L(0xfa), L(0xc6), L(0xba),
-                L(0x7a), L(0x43), L(0x71), L(0x5),  L(0xf5), L(0x68), L(0x69), L(0x85), L(0x9c), L(0xba), L(0x45), L(0xcd), L(0x6b), L(0xb),
-                L(0x19), L(0xd1), L(0xbb), L(0x7f), L(0x70), L(0x85), L(0x92), L(0xd1), L(0xb4), L(0x64), L(0x82), L(0xb1), L(0xe4), L(0x62),
-                L(0xc5), L(0x3c), L(0x46), L(0x1f), L(0x92), L(0x31), L(0x1c), L(0x4e), L(0x41), L(0x77), L(0xf7), L(0xe7), L(0x87), L(0xa2),
-                L(0xf),  L(0x6e), L(0xe8), L(0x92), L(0x3),  L(0x6b), L(0xa),  L(0xe7), L(0xa9), L(0x3b), L(0x11), L(0xda), L(0x66), L(0x8a),
-                L(0x29), L(0xda), L(0x79), L(0xe1), L(0x64), L(0x8d), L(0xe3), L(0x54), L(0xd4), L(0xf5), L(0xef), L(0x64), L(0x87), L(0x3b),
-                L(0xf4), L(0xc2), L(0xf4), L(0x71), L(0x13), L(0xa9), L(0xe9), L(0xe0), L(0xa2), L(0x6),  L(0x14), L(0xab), L(0x5d), L(0xa7),
-                L(0x96), L(0x0),  L(0xd6), L(0xc3), L(0xcc), L(0x57), L(0xed), L(0x39), L(0x6a), L(0x25), L(0xcd), L(0x76), L(0xea), L(0xba),
-                L(0x3a), L(0xf2), L(0xa1), L(0x95), L(0x5d), L(0xe5), L(0x71), L(0xcf), L(0x9c), L(0x62), L(0x9e), L(0x6a), L(0xfa), L(0xd5),
-                L(0x31), L(0xd1), L(0xa8), L(0x66), L(0x30), L(0x33), L(0xaa), L(0x51), L(0x17), L(0x13), L(0x82), L(0x99), L(0xc8), L(0x14),
-                L(0x60), L(0x9f), L(0x4d), L(0x32), L(0x6d), L(0xda), L(0x19), L(0x26), L(0x21), L(0xdc), L(0x7e), L(0x2e), L(0x25), L(0x67),
-                L(0x72), L(0xca), L(0xf),  L(0x92), L(0xcd), L(0xf6), L(0xd6), L(0xcb), L(0x97), L(0x8a), L(0x33), L(0x58), L(0x73), L(0x70),
-                L(0x91), L(0x1d), L(0xbf), L(0x28), L(0x23), L(0xa3), L(0xc),  L(0xf1), L(0x83), L(0xc3), L(0xc8), L(0x56), L(0x77), L(0x68),
-                L(0xe3), L(0x82), L(0xba), L(0xb9), L(0x57), L(0x56), L(0x57), L(0x9c), L(0xc3), L(0xd6), L(0x14), L(0x5),  L(0x3c), L(0xb1),
-                L(0xaf), L(0x93), L(0xc8), L(0x8a), L(0x57), L(0x7f), L(0x53), L(0xfa), L(0x2f), L(0xaa), L(0x6e), L(0x66), L(0x83), L(0xfa),
-                L(0x33), L(0xd1), L(0x21), L(0xab), L(0x1b), L(0x71), L(0xb4), L(0x7c), L(0xda), L(0xfd), L(0xfb), L(0x7f), L(0x20), L(0xab),
-                L(0x5e), L(0xd5), L(0xca), L(0xfd), L(0xdd), L(0xe0), L(0xee), L(0xda), L(0xba), L(0xa8), L(0x27), L(0x99), L(0x97), L(0x69),
-                L(0xc1), L(0x3c), L(0x82), L(0x8c), L(0xa),  L(0x5c), L(0x2d), L(0x5b), L(0x88), L(0x3e), L(0x34), L(0x35), L(0x86), L(0x37),
-                L(0x46), L(0x79), L(0xe1), L(0xaa), L(0x19), L(0xfb), L(0xaa), L(0xde), L(0x15), L(0x9),  L(0xd),  L(0x1a), L(0x57), L(0xff),
-                L(0xb5), L(0xf),  L(0xf3), L(0x2b), L(0x5a), L(0x6a), L(0x4d), L(0x19), L(0x77), L(0x71), L(0x45), L(0xdf), L(0x4f), L(0xb3),
-                L(0xec), L(0xf1), L(0xeb), L(0x18), L(0x53), L(0x3e), L(0x3b), L(0x47), L(0x8),  L(0x9a), L(0x73), L(0xa0), L(0x5c), L(0x8c),
-                L(0x5f), L(0xeb), L(0xf),  L(0x3a), L(0xc2), L(0x43), L(0x67), L(0xb4), L(0x66), L(0x67), L(0x80), L(0x58), L(0xe),  L(0xc1),
-                L(0xec), L(0x40), L(0xd4), L(0x22), L(0x94), L(0xca), L(0xf9), L(0xe8), L(0x92), L(0xe4), L(0x69), L(0x38), L(0xbe), L(0x67),
-                L(0x64), L(0xca), L(0x50), L(0xc7), L(0x6),  L(0x67), L(0x42), L(0x6e), L(0xa3), L(0xf0), L(0xb7), L(0x6c), L(0xf2), L(0xe8),
-                L(0x5f), L(0xb1), L(0xaf), L(0xe7), L(0xdb), L(0xbb), L(0x77), L(0xb5), L(0xf8), L(0xcb), L(0x8),  L(0xc4), L(0x75), L(0x7e),
-                L(0xc0), L(0xf9), L(0x1c), L(0x7f), L(0x3c), L(0x89), L(0x2f), L(0xd2), L(0x58), L(0x3a), L(0xe2), L(0xf8), L(0x91), L(0xb6),
-                L(0x7b), L(0x24), L(0x27), L(0xe9), L(0xae), L(0x84), L(0x8b), L(0xde), L(0x74), L(0xac), L(0xfd), L(0xd9), L(0xb7), L(0x69),
-                L(0x2a), L(0xec), L(0x32), L(0x6f), L(0xf0), L(0x92), L(0x84), L(0xf1), L(0x40), L(0xc),  L(0x8a), L(0xbc), L(0x39), L(0x6e),
-                L(0x2e), L(0x73), L(0xd4), L(0x6e), L(0x8a), L(0x74), L(0x2a), L(0xdc), L(0x60), L(0x1f), L(0xa3), L(0x7),  L(0xde), L(0x75),
-                L(0x8b), L(0x74), L(0xc8), L(0xfe), L(0x63), L(0x75), L(0xf6), L(0x3d), L(0x63), L(0xac), L(0x33), L(0x89), L(0xc3), L(0xf0),
-                L(0xf8), L(0x2d), L(0x6b), L(0xb4), L(0x9e), L(0x74), L(0x8b), L(0x5c), L(0x33), L(0xb4), L(0xca), L(0xa8), L(0xe4), L(0x99),
-                L(0xb6), L(0x90), L(0xa1), L(0xef), L(0xf),  L(0xd3), L(0x61), L(0xb2), L(0xc6), L(0x1a), L(0x94), L(0x7c), L(0x44), L(0x55),
-                L(0xf4), L(0x45), L(0xff), L(0x9e), L(0xa5), L(0x5a), L(0xc6), L(0xa0), L(0xe8), L(0x2a), L(0xc1), L(0x8d), L(0x6f), L(0x34),
-                L(0x11), L(0xb9), L(0xbe), L(0x4e), L(0xd9), L(0x87), L(0x97), L(0x73), L(0xcf), L(0x3d), L(0x23), L(0xae), L(0xd5), L(0x1a),
-                L(0x5e), L(0xae), L(0x5d), L(0x6a), L(0x3),  L(0xf9), L(0x22), L(0xd),  L(0x10), L(0xd9), L(0x47), L(0x69), L(0x15), L(0x3f),
-                L(0xee), L(0x52), L(0xa3), L(0x8),  L(0xd2), L(0x3c), L(0x51), L(0xf4), L(0xf8), L(0x9d), L(0xe4), L(0x98), L(0x89), L(0xc8),
-                L(0x67), L(0x39), L(0xd5), L(0x5e), L(0x35), L(0x78), L(0x27), L(0xe8), L(0x3c), L(0x80), L(0xae), L(0x79), L(0x71), L(0xd2),
-                L(0x93), L(0xf4), L(0xaa), L(0x51), L(0x12), L(0x1c), L(0x4b), L(0x1b), L(0xe5), L(0x6e), L(0x15), L(0x6f), L(0xe4), L(0xbb),
-                L(0x51), L(0x9b), L(0x45), L(0x9f), L(0xf9), L(0xc4), L(0x8c), L(0x2a), L(0xfb), L(0x1a), L(0xdf), L(0x55), L(0xd3), L(0x48),
-                L(0x93), L(0x27), L(0x1),  L(0x26), L(0xc2), L(0x6b), L(0x55), L(0x6d), L(0xa2), L(0xfb), L(0x84), L(0x8b), L(0xc9), L(0x9e),
-                L(0x28), L(0xc2), L(0xef), L(0x1a), L(0x24), L(0xec), L(0x9b), L(0xae), L(0xbd), L(0x60), L(0xe9), L(0x15), L(0x35), L(0xee),
-                L(0x42), L(0xa4), L(0x33), L(0x5b), L(0xfa), L(0xf),  L(0xb6), L(0xf7), L(0x1),  L(0xa6), L(0x2),  L(0x4c), L(0xca), L(0x90),
-                L(0x58), L(0x3a), L(0x96), L(0x41), L(0xe7), L(0xcb), L(0x9),  L(0x8c), L(0xdb), L(0x85), L(0x4d), L(0xa8), L(0x89), L(0xf3),
-                L(0xb5), L(0x8e), L(0xfd), L(0x75), L(0x5b), L(0x4f), L(0xed), L(0xde), L(0x3f), L(0xeb), L(0x38), L(0xa3), L(0xbe), L(0xb0),
-                L(0x73), L(0xfc), L(0xb8), L(0x54), L(0xf7), L(0x4c), L(0x30), L(0x67), L(0x2e), L(0x38), L(0xa2), L(0x54), L(0x18), L(0xba),
-                L(0x8),  L(0xbf), L(0xf2), L(0x39), L(0xd5), L(0xfe), L(0xa5), L(0x41), L(0xc6), L(0x66), L(0x66), L(0xba), L(0x81), L(0xef),
-                L(0x67), L(0xe4), L(0xe6), L(0x3c), L(0xc),  L(0xca), L(0xa4), L(0xa),  L(0x79), L(0xb3), L(0x57), L(0x8b), L(0x8a), L(0x75),
-                L(0x98), L(0x18), L(0x42), L(0x2f), L(0x29), L(0xa3), L(0x82), L(0xef), L(0x9f), L(0x86), L(0x6),  L(0x23), L(0xe1), L(0x75),
-                L(0xfa), L(0x8),  L(0xb1), L(0xde), L(0x17), L(0x4a),
-            },
-        },
-        TestCase{
-            .input = "huffman-rand-limit.input",
-            .want = "huffman-rand-limit.{s}.expect",
-            .want_no_input = "huffman-rand-limit.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L(0x61), M(1, 74), L(0xa),  L(0xf8), L(0x8b), L(0x96), L(0x76), L(0x48), L(0xa),  L(0x85), L(0x94), L(0x25), L(0x80),
-                L(0xaf), L(0xc2),  L(0xfe), L(0x8d), L(0xe8), L(0x20), L(0xeb), L(0x17), L(0x86), L(0xc9), L(0xb7), L(0xc5), L(0xde),
-                L(0x6),  L(0xea),  L(0x7d), L(0x18), L(0x8b), L(0xe7), L(0x3e), L(0x7),  L(0xda), L(0xdf), L(0xff), L(0x6c), L(0x73),
-                L(0xde), L(0xcc),  L(0xe7), L(0x6d), L(0x8d), L(0x4),  L(0x19), L(0x49), L(0x7f), L(0x47), L(0x1f), L(0x48), L(0x15),
-                L(0xb0), L(0xe8),  L(0x9e), L(0xf2), L(0x31), L(0x59), L(0xde), L(0x34), L(0xb4), L(0x5b), L(0xe5), L(0xe0), L(0x9),
-                L(0x11), L(0x30),  L(0xc2), L(0x88), L(0x5b), L(0x7c), L(0x5d), L(0x14), L(0x13), L(0x6f), L(0x23), L(0xa9), L(0xa),
-                L(0xbc), L(0x2d),  L(0x23), L(0xbe), L(0xd9), L(0xed), L(0x75), L(0x4),  L(0x6c), L(0x99), L(0xdf), L(0xfd), L(0x70),
-                L(0x66), L(0xe6),  L(0xee), L(0xd9), L(0xb1), L(0x9e), L(0x6e), L(0x83), L(0x59), L(0xd5), L(0xd4), L(0x80), L(0x59),
-                L(0x98), L(0x77),  L(0x89), L(0x43), L(0x38), L(0xc9), L(0xaf), L(0x30), L(0x32), L(0x9a), L(0x20), L(0x1b), L(0x46),
-                L(0x3d), L(0x67),  L(0x6e), L(0xd7), L(0x72), L(0x9e), L(0x4e), L(0x21), L(0x4f), L(0xc6), L(0xe0), L(0xd4), L(0x7b),
-                L(0x4),  L(0x8d),  L(0xa5), L(0x3),  L(0xf6), L(0x5),  L(0x9b), L(0x6b), L(0xdc), L(0x2a), L(0x93), L(0x77), L(0x28),
-                L(0xfd), L(0xb4),  L(0x62), L(0xda), L(0x20), L(0xe7), L(0x1f), L(0xab), L(0x6b), L(0x51), L(0x43), L(0x39), L(0x2f),
-                L(0xa0), L(0x92),  L(0x1),  L(0x6c), L(0x75), L(0x3e), L(0xf4), L(0x35), L(0xfd), L(0x43), L(0x2e), L(0xf7), L(0xa4),
-                L(0x75), L(0xda),  L(0xea), L(0x9b), L(0xa),
-            },
-        },
-        TestCase{
-            .input = "huffman-shifts.input",
-            .want = "huffman-shifts.{s}.expect",
-            .want_no_input = "huffman-shifts.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L('1'),    L('0'),    M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258),
-                M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258),
-                M(2, 258), M(2, 76),  L(0xd),    L(0xa),    L('2'),    L('3'),    M(2, 258), M(2, 258),
-                M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 258), M(2, 256),
-            },
-        },
-        TestCase{
-            .input = "huffman-text-shift.input",
-            .want = "huffman-text-shift.{s}.expect",
-            .want_no_input = "huffman-text-shift.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L('/'),   L('/'), L('C'),   L('o'), L('p'),   L('y'),   L('r'),   L('i'),
-                L('g'),   L('h'), L('t'),   L('2'), L('0'),   L('0'),   L('9'),   L('T'),
-                L('h'),   L('G'), L('o'),   L('A'), L('u'),   L('t'),   L('h'),   L('o'),
-                L('r'),   L('.'), L('A'),   L('l'), L('l'),   M(23, 5), L('r'),   L('r'),
-                L('v'),   L('d'), L('.'),   L(0xd), L(0xa),   L('/'),   L('/'),   L('U'),
-                L('o'),   L('f'), L('t'),   L('h'), L('i'),   L('o'),   L('u'),   L('r'),
-                L('c'),   L('c'), L('o'),   L('d'), L('i'),   L('g'),   L('o'),   L('v'),
-                L('r'),   L('n'), L('d'),   L('b'), L('y'),   L('B'),   L('S'),   L('D'),
-                L('-'),   L('t'), L('y'),   L('l'), M(33, 4), L('l'),   L('i'),   L('c'),
-                L('n'),   L('t'), L('h'),   L('t'), L('c'),   L('n'),   L('b'),   L('f'),
-                L('o'),   L('u'), L('n'),   L('d'), L('i'),   L('n'),   L('t'),   L('h'),
-                L('L'),   L('I'), L('C'),   L('E'), L('N'),   L('S'),   L('E'),   L('f'),
-                L('i'),   L('l'), L('.'),   L(0xd), L(0xa),   L(0xd),   L(0xa),   L('p'),
-                L('c'),   L('k'), L('g'),   L('m'), L('i'),   L('n'),   M(11, 4), L('i'),
-                L('m'),   L('p'), L('o'),   L('r'), L('t'),   L('"'),   L('o'),   L('"'),
-                M(13, 4), L('f'), L('u'),   L('n'), L('c'),   L('m'),   L('i'),   L('n'),
-                L('('),   L(')'), L('{'),   L(0xd), L(0xa),   L(0x9),   L('v'),   L('r'),
-                L('b'),   L('='), L('m'),   L('k'), L('('),   L('['),   L(']'),   L('b'),
-                L('y'),   L('t'), L(','),   L('6'), L('5'),   L('5'),   L('3'),   L('5'),
-                L(')'),   L(0xd), L(0xa),   L(0x9), L('f'),   L(','),   L('_'),   L(':'),
-                L('='),   L('o'), L('.'),   L('C'), L('r'),   L('t'),   L('('),   L('"'),
-                L('h'),   L('u'), L('f'),   L('f'), L('m'),   L('n'),   L('-'),   L('n'),
-                L('u'),   L('l'), L('l'),   L('-'), L('m'),   L('x'),   L('.'),   L('i'),
-                L('n'),   L('"'), M(34, 5), L('.'), L('W'),   L('r'),   L('i'),   L('t'),
-                L('('),   L('b'), L(')'),   L(0xd), L(0xa),   L('}'),   L(0xd),   L(0xa),
-                L('A'),   L('B'), L('C'),   L('D'), L('E'),   L('F'),   L('G'),   L('H'),
-                L('I'),   L('J'), L('K'),   L('L'), L('M'),   L('N'),   L('O'),   L('P'),
-                L('Q'),   L('R'), L('S'),   L('T'), L('U'),   L('V'),   L('X'),   L('x'),
-                L('y'),   L('z'), L('!'),   L('"'), L('#'),   L(0xc2),  L(0xa4),  L('%'),
-                L('&'),   L('/'), L('?'),   L('"'),
-            },
-        },
-        TestCase{
-            .input = "huffman-text.input",
-            .want = "huffman-text.{s}.expect",
-            .want_no_input = "huffman-text.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L('/'),    L('/'),    L(' '),   L('z'),    L('i'), L('g'), L(' '), L('v'),
-                L('0'),    L('.'),    L('1'),   L('0'),    L('.'), L('0'), L(0xa), L('/'),
-                L('/'),    L(' '),    L('c'),   L('r'),    L('e'), L('a'), L('t'), L('e'),
-                L(' '),    L('a'),    L(' '),   L('f'),    L('i'), L('l'), L('e'), M(5, 4),
-                L('l'),    L('e'),    L('d'),   L(' '),    L('w'), L('i'), L('t'), L('h'),
-                L(' '),    L('0'),    L('x'),   L('0'),    L('0'), L(0xa), L('c'), L('o'),
-                L('n'),    L('s'),    L('t'),   L(' '),    L('s'), L('t'), L('d'), L(' '),
-                L('='),    L(' '),    L('@'),   L('i'),    L('m'), L('p'), L('o'), L('r'),
-                L('t'),    L('('),    L('"'),   L('s'),    L('t'), L('d'), L('"'), L(')'),
-                L(';'),    L(0xa),    L(0xa),   L('p'),    L('u'), L('b'), L(' '), L('f'),
-                L('n'),    L(' '),    L('m'),   L('a'),    L('i'), L('n'), L('('), L(')'),
-                L(' '),    L('!'),    L('v'),   L('o'),    L('i'), L('d'), L(' '), L('{'),
-                L(0xa),    L(' '),    L(' '),   L(' '),    L(' '), L('v'), L('a'), L('r'),
-                L(' '),    L('b'),    L(' '),   L('='),    L(' '), L('['), L('1'), L(']'),
-                L('u'),    L('8'),    L('{'),   L('0'),    L('}'), L(' '), L('*'), L('*'),
-                L(' '),    L('6'),    L('5'),   L('5'),    L('3'), L('5'), L(';'), M(31, 5),
-                M(86, 6),  L('f'),    L(' '),   L('='),    L(' '), L('t'), L('r'), L('y'),
-                M(94, 4),  L('.'),    L('f'),   L('s'),    L('.'), L('c'), L('w'), L('d'),
-                L('('),    L(')'),    L('.'),   M(144, 6), L('F'), L('i'), L('l'), L('e'),
-                L('('),    M(43, 5),  M(1, 4),  L('"'),    L('h'), L('u'), L('f'), L('f'),
-                L('m'),    L('a'),    L('n'),   L('-'),    L('n'), L('u'), L('l'), L('l'),
-                L('-'),    L('m'),    L('a'),   L('x'),    L('.'), L('i'), L('n'), L('"'),
-                L(','),    M(31, 9),  L('.'),   L('{'),    L(' '), L('.'), L('r'), L('e'),
-                L('a'),    L('d'),    M(79, 5), L('u'),    L('e'), L(' '), L('}'), M(27, 6),
-                L(')'),    M(108, 6), L('d'),   L('e'),    L('f'), L('e'), L('r'), L(' '),
-                L('f'),    L('.'),    L('c'),   L('l'),    L('o'), L('s'), L('e'), L('('),
-                M(183, 4), M(22, 4),  L('_'),   M(124, 7), L('f'), L('.'), L('w'), L('r'),
-                L('i'),    L('t'),    L('e'),   L('A'),    L('l'), L('l'), L('('), L('b'),
-                L('['),    L('0'),    L('.'),   L('.'),    L(']'), L(')'), L(';'), L(0xa),
-                L('}'),    L(0xa),
-            },
-        },
-        TestCase{
-            .input = "huffman-zero.input",
-            .want = "huffman-zero.{s}.expect",
-            .want_no_input = "huffman-zero.{s}.expect-noinput",
-            .tokens = &[_]Token{ L(0x30), ml, M(1, 49) },
-        },
-        TestCase{
-            .input = "",
-            .want = "",
-            .want_no_input = "null-long-match.{s}.expect-noinput",
-            .tokens = &[_]Token{
-                L(0x0), ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, ml,      ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml, ml,
-                ml,     ml, ml, M(1, 8),
-            },
-        },
-    };
-};
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.dyn.expect
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index c08165143f..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.dyn.expect-noinput
deleted file mode 100644
index c08165143f..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.huff.expect
deleted file mode 100644
index db422ca398..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.input b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.input
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.wb.expect
deleted file mode 100644
index c08165143f..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-null-max.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-null-max.wb.expect-noinput
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-pi.dyn.expect
deleted file mode 100644
index e4396ac6fe..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-pi.dyn.expect-noinput
deleted file mode 100644
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-pi.huff.expect
deleted file mode 100644
index 23d8f7f98b..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.input b/lib/std/compress/flate/testdata/block_writer/huffman-pi.input
deleted file mode 100644
index efaed43431..0000000000
--- a/lib/std/compress/flate/testdata/block_writer/huffman-pi.input
+++ /dev/null
@@ -1 +0,0 @@
-3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920962829254091715364367892590360011330530548820466521384146951941511609433057270365759591953092186117381932611793105118548074462379962749567351885752724891227938183011949129833673362440656643086021394946395224737190702179860943702770539217176293176752384674818467669405132000568127145263560827785771342757789609173637178721468440901224953430146549585371050792279689258923542019956112129021960864034418159813629774771309960518707211349999998372978049951059731732816096318595024459455346908302642522308253344685035261931188171010003137838752886587533208381420617177669147303598253490428755468731159562863882353787593751957781857780532171226806613001927876611195909216420198938095257201065485863278865936153381827968230301952035301852968995773622599413891249721775283479131515574857242454150695950829533116861727855889075098381754637464939319255060400927701671139009848824012858361603563707660104710181942955596198946767837449448255379774726847104047534646208046684259069491293313677028989152104752162056966024058038150193511253382430035587640247496473263914199272604269922796782354781636009341721641219924586315030286182974555706749838505494588586926995690927210797509302955321165344987202755960236480665499119881834797753566369807426542527862551818417574672890977772793800081647060016145249192173217214772350141441973568548161361157352552133475741849468438523323907394143334547762416862518983569485562099219222184272550254256887671790494601653466804988627232791786085784383827967976681454100953883786360950680064225125205117392984896084128488626945604241965285022210661186306744278622039194945047123713786960956364371917287467764657573962413890865832645995813390478027590099465764078951269468398352595709825822620522489407726719478268482601476990902640136394437455305068203496252451749399651431429809190659250937221696461515709858387410597885959772975498930161753928468138268683868942774155991855925245953959431049972524680845987273644695848653836736222626099124608051243884390451244136549762780797715691435997700129616089441694868555848406353422072225828488648158456028506016842739452267467678895252138522549954666727823986456596116354886230577456498035593634568174324112515076069479451096596094025228879710893145669136867228748940560101503308617928680920874760917824938589009714909675985261365549781893129784821682998948722658804857564014270477555132379641451523746234364542858444795265867821051141354735739523113427166102135969536231442952484937187110145765403590279934403742007310578539062198387447808478489683321445713868751943506430218453191048481005370614680674919278191197939952061419663428754440643745123718192179998391015919561814675142691239748940907186494231961567945208095146550225231603881930142093762137855956638937787083039069792077346722182562599661501421503068038447734549202605414665925201497442850732518666002132434088190710486331734649651453905796268561005508106658796998163574736384052571459102897064140110971206280439039759515677157700420337869936007230558763176359421873125147120532928191826186125867321579198414848829164470609575270695722091756711672291098169091528017350671274858322287183520935396572512108357915136988209144421006751033467110314126711136990865851639831501970165151168517143765761835155650884909989859982387345528331635507647918535893226185489632132933089857064204675259070915481416549859461637180
\ No newline at end of file
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-pi.wb.expect
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-pi.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-pi.wb.expect-noinput
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.dyn.expect
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.input b/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.input
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.wb.expect
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-rand-1k.wb.expect-noinput
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.dyn.expect
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.dyn.expect-noinput
deleted file mode 100644
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.huff.expect
deleted file mode 100644
index 57e59322e9..0000000000
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diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.input b/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.input
deleted file mode 100644
index fb5b1be619..0000000000
--- a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.input
+++ /dev/null
@@ -1,4 +0,0 @@
-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-ø‹–vH
-…”%€¯Âþ�è ë†É·ÅÞê}‹ç>ÚßÿlsÞÌçm�IGH°èžò1YÞ4´[åà	0ˆ[|]o#©
-¼-#¾Ùíul™ßýpfæîÙ±žnƒYÕÔ€Y˜w‰C8ɯ02š F=gn×ržN!OÆàÔ{�¥ö›kÜ*“w(ý´bÚ ç«kQC9/ ’
lu>ô5ýC.÷¤uÚê›
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-rand-limit.wb.expect
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--- a/lib/std/compress/flate/testdata/block_writer/huffman-shifts.input
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-232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323232323
\ No newline at end of file
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-shifts.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-shifts.wb.expect
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index 7812c1c62d..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-shifts.wb.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect
deleted file mode 100644
index 71ce3aeb75..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect-noinput
deleted file mode 100644
index 71ce3aeb75..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.dyn.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.huff.expect
deleted file mode 100644
index ff023114bb..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.huff.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.input b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.input
deleted file mode 100644
index cc5c3ad69d..0000000000
--- a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.input
+++ /dev/null
@@ -1,14 +0,0 @@
-//Copyright2009ThGoAuthor.Allrightrrvd.
-//UofthiourccodigovrndbyBSD-tyl
-//licnthtcnbfoundinthLICENSEfil.
-
-pckgmin
-
-import"o"
-
-funcmin(){
-	vrb=mk([]byt,65535)
-	f,_:=o.Crt("huffmn-null-mx.in")
-	f.Writ(b)
-}
-ABCDEFGHIJKLMNOPQRSTUVXxyz!"#¤%&/?"
\ No newline at end of file
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect
deleted file mode 100644
index 71ce3aeb75..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect-noinput
deleted file mode 100644
index 71ce3aeb75..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text-shift.wb.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect
deleted file mode 100644
index fbffc3f36b..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect-noinput
deleted file mode 100644
index fbffc3f36b..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text.dyn.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text.huff.expect
deleted file mode 100644
index 46fa51fdad..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text.huff.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.input b/lib/std/compress/flate/testdata/block_writer/huffman-text.input
deleted file mode 100644
index df97174253..0000000000
--- a/lib/std/compress/flate/testdata/block_writer/huffman-text.input
+++ /dev/null
@@ -1,14 +0,0 @@
-// zig v0.10.0
-// create a file filled with 0x00
-const std = @import("std");
-
-pub fn main() !void {
-    var b = [1]u8{0} ** 65535;
-    const f = try std.fs.cwd().createFile(
-        "huffman-null-max.in",
-        .{ .read = true },
-    );
-    defer f.close();
-
-    _ = try f.writeAll(b[0..]);
-}
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect
deleted file mode 100644
index fbffc3f36b..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect-noinput
deleted file mode 100644
index fbffc3f36b..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-text.wb.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect b/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect
deleted file mode 100644
index 830348a79a..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect-noinput
deleted file mode 100644
index 830348a79a..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-zero.dyn.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.huff.expect b/lib/std/compress/flate/testdata/block_writer/huffman-zero.huff.expect
deleted file mode 100644
index 5abdbaff9a..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-zero.huff.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.input b/lib/std/compress/flate/testdata/block_writer/huffman-zero.input
deleted file mode 100644
index 349be0e6ec..0000000000
--- a/lib/std/compress/flate/testdata/block_writer/huffman-zero.input
+++ /dev/null
@@ -1 +0,0 @@
-00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
\ No newline at end of file
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect b/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect
deleted file mode 100644
index dbe401c54c..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect-noinput
deleted file mode 100644
index dbe401c54c..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/huffman-zero.wb.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/null-long-match.dyn.expect-noinput b/lib/std/compress/flate/testdata/block_writer/null-long-match.dyn.expect-noinput
deleted file mode 100644
index 8b92d9fc20..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/null-long-match.dyn.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/flate/testdata/block_writer/null-long-match.wb.expect-noinput b/lib/std/compress/flate/testdata/block_writer/null-long-match.wb.expect-noinput
deleted file mode 100644
index 8b92d9fc20..0000000000
Binary files a/lib/std/compress/flate/testdata/block_writer/null-long-match.wb.expect-noinput and /dev/null differ
diff --git a/lib/std/compress/gzip.zig b/lib/std/compress/gzip.zig
deleted file mode 100644
index e619b575de..0000000000
--- a/lib/std/compress/gzip.zig
+++ /dev/null
@@ -1,66 +0,0 @@
-const deflate = @import("flate/deflate.zig");
-const inflate = @import("flate/inflate.zig");
-
-/// Decompress compressed data from reader and write plain data to the writer.
-pub fn decompress(reader: anytype, writer: anytype) !void {
-    try inflate.decompress(.gzip, reader, writer);
-}
-
-/// Decompressor type
-pub fn Decompressor(comptime ReaderType: type) type {
-    return inflate.Decompressor(.gzip, ReaderType);
-}
-
-/// Create Decompressor which will read compressed data from reader.
-pub fn decompressor(reader: anytype) Decompressor(@TypeOf(reader)) {
-    return inflate.decompressor(.gzip, reader);
-}
-
-/// Compression level, trades between speed and compression size.
-pub const Options = deflate.Options;
-
-/// Compress plain data from reader and write compressed data to the writer.
-pub fn compress(reader: anytype, writer: anytype, options: Options) !void {
-    try deflate.compress(.gzip, reader, writer, options);
-}
-
-/// Compressor type
-pub fn Compressor(comptime WriterType: type) type {
-    return deflate.Compressor(.gzip, WriterType);
-}
-
-/// Create Compressor which outputs compressed data to the writer.
-pub fn compressor(writer: anytype, options: Options) !Compressor(@TypeOf(writer)) {
-    return try deflate.compressor(.gzip, writer, options);
-}
-
-/// Huffman only compression. Without Lempel-Ziv match searching. Faster
-/// compression, less memory requirements but bigger compressed sizes.
-pub const huffman = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.huffman.compress(.gzip, reader, writer);
-    }
-
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.huffman.Compressor(.gzip, WriterType);
-    }
-
-    pub fn compressor(writer: anytype) !huffman.Compressor(@TypeOf(writer)) {
-        return deflate.huffman.compressor(.gzip, writer);
-    }
-};
-
-// No compression store only. Compressed size is slightly bigger than plain.
-pub const store = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.store.compress(.gzip, reader, writer);
-    }
-
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.store.Compressor(.gzip, WriterType);
-    }
-
-    pub fn compressor(writer: anytype) !store.Compressor(@TypeOf(writer)) {
-        return deflate.store.compressor(.gzip, writer);
-    }
-};
diff --git a/lib/std/compress/zlib.zig b/lib/std/compress/zlib.zig
deleted file mode 100644
index 554f6f894b..0000000000
--- a/lib/std/compress/zlib.zig
+++ /dev/null
@@ -1,101 +0,0 @@
-const deflate = @import("flate/deflate.zig");
-const inflate = @import("flate/inflate.zig");
-
-/// Decompress compressed data from reader and write plain data to the writer.
-pub fn decompress(reader: anytype, writer: anytype) !void {
-    try inflate.decompress(.zlib, reader, writer);
-}
-
-/// Decompressor type
-pub fn Decompressor(comptime ReaderType: type) type {
-    return inflate.Decompressor(.zlib, ReaderType);
-}
-
-/// Create Decompressor which will read compressed data from reader.
-pub fn decompressor(reader: anytype) Decompressor(@TypeOf(reader)) {
-    return inflate.decompressor(.zlib, reader);
-}
-
-/// Compression level, trades between speed and compression size.
-pub const Options = deflate.Options;
-
-/// Compress plain data from reader and write compressed data to the writer.
-pub fn compress(reader: anytype, writer: anytype, options: Options) !void {
-    try deflate.compress(.zlib, reader, writer, options);
-}
-
-/// Compressor type
-pub fn Compressor(comptime WriterType: type) type {
-    return deflate.Compressor(.zlib, WriterType);
-}
-
-/// Create Compressor which outputs compressed data to the writer.
-pub fn compressor(writer: anytype, options: Options) !Compressor(@TypeOf(writer)) {
-    return try deflate.compressor(.zlib, writer, options);
-}
-
-/// Huffman only compression. Without Lempel-Ziv match searching. Faster
-/// compression, less memory requirements but bigger compressed sizes.
-pub const huffman = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.huffman.compress(.zlib, reader, writer);
-    }
-
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.huffman.Compressor(.zlib, WriterType);
-    }
-
-    pub fn compressor(writer: anytype) !huffman.Compressor(@TypeOf(writer)) {
-        return deflate.huffman.compressor(.zlib, writer);
-    }
-};
-
-// No compression store only. Compressed size is slightly bigger than plain.
-pub const store = struct {
-    pub fn compress(reader: anytype, writer: anytype) !void {
-        try deflate.store.compress(.zlib, reader, writer);
-    }
-
-    pub fn Compressor(comptime WriterType: type) type {
-        return deflate.store.Compressor(.zlib, WriterType);
-    }
-
-    pub fn compressor(writer: anytype) !store.Compressor(@TypeOf(writer)) {
-        return deflate.store.compressor(.zlib, writer);
-    }
-};
-
-test "should not overshoot" {
-    const std = @import("std");
-
-    // Compressed zlib data with extra 4 bytes at the end.
-    const data = [_]u8{
-        0x78, 0x9c, 0x73, 0xce, 0x2f, 0xa8, 0x2c, 0xca, 0x4c, 0xcf, 0x28, 0x51, 0x08, 0xcf, 0xcc, 0xc9,
-        0x49, 0xcd, 0x55, 0x28, 0x4b, 0xcc, 0x53, 0x08, 0x4e, 0xce, 0x48, 0xcc, 0xcc, 0xd6, 0x51, 0x08,
-        0xce, 0xcc, 0x4b, 0x4f, 0x2c, 0xc8, 0x2f, 0x4a, 0x55, 0x30, 0xb4, 0xb4, 0x34, 0xd5, 0xb5, 0x34,
-        0x03, 0x00, 0x8b, 0x61, 0x0f, 0xa4, 0x52, 0x5a, 0x94, 0x12,
-    };
-
-    var stream = std.io.fixedBufferStream(data[0..]);
-    const reader = stream.reader();
-
-    var dcp = decompressor(reader);
-    var out: [128]u8 = undefined;
-
-    // Decompress
-    var n = try dcp.reader().readAll(out[0..]);
-
-    // Expected decompressed data
-    try std.testing.expectEqual(46, n);
-    try std.testing.expectEqualStrings("Copyright Willem van Schaik, Singapore 1995-96", out[0..n]);
-
-    // Decompressor don't overshoot underlying reader.
-    // It is leaving it at the end of compressed data chunk.
-    try std.testing.expectEqual(data.len - 4, stream.getPos());
-    try std.testing.expectEqual(0, dcp.unreadBytes());
-
-    // 4 bytes after compressed chunk are available in reader.
-    n = try reader.readAll(out[0..]);
-    try std.testing.expectEqual(n, 4);
-    try std.testing.expectEqualSlices(u8, data[data.len - 4 .. data.len], out[0..n]);
-}
diff --git a/lib/std/compress/zstd/Decompress.zig b/lib/std/compress/zstd/Decompress.zig
index db85474e00..bcb8e3b0da 100644
--- a/lib/std/compress/zstd/Decompress.zig
+++ b/lib/std/compress/zstd/Decompress.zig
@@ -89,7 +89,7 @@ pub fn init(input: *Reader, buffer: []u8, options: Options) Decompress {
                 .stream = stream,
                 .rebase = rebase,
                 .discard = discard,
-                .readVec = Reader.indirectReadVec,
+                .readVec = readVec,
             },
             .buffer = buffer,
             .seek = 0,
@@ -109,10 +109,24 @@ fn rebase(r: *Reader, capacity: usize) Reader.RebaseError!void {
     r.seek -= discard_n;
 }
 
-fn discard(r: *Reader, limit: Limit) Reader.Error!usize {
-    r.rebase(zstd.block_size_max) catch unreachable;
-    var d: Writer.Discarding = .init(r.buffer);
-    const n = r.stream(&d.writer, limit) catch |err| switch (err) {
+/// This could be improved so that when an amount is discarded that includes an
+/// entire frame, skip decoding that frame.
+fn discard(r: *Reader, limit: std.Io.Limit) Reader.Error!usize {
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    r.rebase(d.window_len) catch unreachable;
+    var writer: Writer = .{
+        .vtable = &.{
+            .drain = std.Io.Writer.Discarding.drain,
+            .sendFile = std.Io.Writer.Discarding.sendFile,
+        },
+        .buffer = r.buffer,
+        .end = r.end,
+    };
+    defer {
+        r.end = writer.end;
+        r.seek = r.end;
+    }
+    const n = r.stream(&writer, limit) catch |err| switch (err) {
         error.WriteFailed => unreachable,
         error.ReadFailed => return error.ReadFailed,
         error.EndOfStream => return error.EndOfStream,
@@ -121,6 +135,23 @@ fn discard(r: *Reader, limit: Limit) Reader.Error!usize {
     return n;
 }
 
+fn readVec(r: *Reader, data: [][]u8) Reader.Error!usize {
+    _ = data;
+    const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
+    assert(r.seek == r.end);
+    r.rebase(d.window_len) catch unreachable;
+    var writer: Writer = .{
+        .buffer = r.buffer,
+        .end = r.end,
+        .vtable = &.{ .drain = Writer.fixedDrain },
+    };
+    r.end += r.vtable.stream(r, &writer, .limited(writer.buffer.len - writer.end)) catch |err| switch (err) {
+        error.WriteFailed => unreachable,
+        else => |e| return e,
+    };
+    return 0;
+}
+
 fn stream(r: *Reader, w: *Writer, limit: Limit) Reader.StreamError!usize {
     const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
     const in = d.input;
diff --git a/lib/std/debug/Dwarf.zig b/lib/std/debug/Dwarf.zig
index 3f1fc41feb..6237d06cda 100644
--- a/lib/std/debug/Dwarf.zig
+++ b/lib/std/debug/Dwarf.zig
@@ -2019,10 +2019,14 @@ pub fn compactUnwindToDwarfRegNumber(unwind_reg_number: u3) !u8 {
 /// This function is to make it handy to comment out the return and make it
 /// into a crash when working on this file.
 pub fn bad() error{InvalidDebugInfo} {
-    if (debug_debug_mode) @panic("bad dwarf");
+    invalidDebugInfoDetected();
     return error.InvalidDebugInfo;
 }
 
+fn invalidDebugInfoDetected() void {
+    if (debug_debug_mode) @panic("bad dwarf");
+}
+
 fn missing() error{MissingDebugInfo} {
     if (debug_debug_mode) @panic("missing dwarf");
     return error.MissingDebugInfo;
@@ -2235,21 +2239,23 @@ pub const ElfModule = struct {
 
             const section_bytes = try chopSlice(mapped_mem, shdr.sh_offset, shdr.sh_size);
             sections[section_index.?] = if ((shdr.sh_flags & elf.SHF_COMPRESSED) > 0) blk: {
-                var section_stream = std.io.fixedBufferStream(section_bytes);
-                const section_reader = section_stream.reader();
-                const chdr = section_reader.readStruct(elf.Chdr) catch continue;
+                var section_reader: std.Io.Reader = .fixed(section_bytes);
+                const chdr = section_reader.takeStruct(elf.Chdr, endian) catch continue;
                 if (chdr.ch_type != .ZLIB) continue;
 
-                var zlib_stream = std.compress.zlib.decompressor(section_reader);
-
-                const decompressed_section = try gpa.alloc(u8, chdr.ch_size);
-                errdefer gpa.free(decompressed_section);
-
-                const read = zlib_stream.reader().readAll(decompressed_section) catch continue;
-                assert(read == decompressed_section.len);
-
+                var decompress: std.compress.flate.Decompress = .init(&section_reader, .zlib, &.{});
+                var decompressed_section: std.ArrayListUnmanaged(u8) = .empty;
+                defer decompressed_section.deinit(gpa);
+                decompress.reader.appendRemainingUnlimited(gpa, null, &decompressed_section, std.compress.flate.history_len) catch {
+                    invalidDebugInfoDetected();
+                    continue;
+                };
+                if (chdr.ch_size != decompressed_section.items.len) {
+                    invalidDebugInfoDetected();
+                    continue;
+                }
                 break :blk .{
-                    .data = decompressed_section,
+                    .data = try decompressed_section.toOwnedSlice(gpa),
                     .virtual_address = shdr.sh_addr,
                     .owned = true,
                 };
diff --git a/lib/std/fs/File.zig b/lib/std/fs/File.zig
index eca2d6667f..9776854f18 100644
--- a/lib/std/fs/File.zig
+++ b/lib/std/fs/File.zig
@@ -1105,22 +1105,6 @@ pub fn deprecatedWriter(file: File) DeprecatedWriter {
     return .{ .context = file };
 }
 
-/// Deprecated in favor of `Reader` and `Writer`.
-pub const SeekableStream = io.SeekableStream(
-    File,
-    SeekError,
-    GetSeekPosError,
-    seekTo,
-    seekBy,
-    getPos,
-    getEndPos,
-);
-
-/// Deprecated in favor of `Reader` and `Writer`.
-pub fn seekableStream(file: File) SeekableStream {
-    return .{ .context = file };
-}
-
 /// Memoizes key information about a file handle such as:
 /// * The size from calling stat, or the error that occurred therein.
 /// * The current seek position.
@@ -1321,7 +1305,7 @@ pub const Reader = struct {
         }
     }
 
-    fn readVec(io_reader: *std.Io.Reader, data: []const []u8) std.Io.Reader.Error!usize {
+    fn readVec(io_reader: *std.Io.Reader, data: [][]u8) std.Io.Reader.Error!usize {
         const r: *Reader = @alignCast(@fieldParentPtr("interface", io_reader));
         switch (r.mode) {
             .positional, .positional_reading => {
diff --git a/lib/std/hash.zig b/lib/std/hash.zig
index 5f1697a236..781971bd13 100644
--- a/lib/std/hash.zig
+++ b/lib/std/hash.zig
@@ -1,5 +1,4 @@
-const adler = @import("hash/adler.zig");
-pub const Adler32 = adler.Adler32;
+pub const Adler32 = @import("hash/Adler32.zig");
 
 const auto_hash = @import("hash/auto_hash.zig");
 pub const autoHash = auto_hash.autoHash;
@@ -116,7 +115,7 @@ test int {
 }
 
 test {
-    _ = adler;
+    _ = Adler32;
     _ = auto_hash;
     _ = crc;
     _ = fnv;
diff --git a/lib/std/hash/Adler32.zig b/lib/std/hash/Adler32.zig
new file mode 100644
index 0000000000..6932dc59da
--- /dev/null
+++ b/lib/std/hash/Adler32.zig
@@ -0,0 +1,117 @@
+//! https://tools.ietf.org/html/rfc1950#section-9
+//! https://github.com/madler/zlib/blob/master/adler32.c
+
+const Adler32 = @This();
+const std = @import("std");
+const testing = std.testing;
+
+adler: u32 = 1,
+
+pub fn permute(state: u32, input: []const u8) u32 {
+    const base = 65521;
+    const nmax = 5552;
+
+    var s1 = state & 0xffff;
+    var s2 = (state >> 16) & 0xffff;
+
+    if (input.len == 1) {
+        s1 +%= input[0];
+        if (s1 >= base) {
+            s1 -= base;
+        }
+        s2 +%= s1;
+        if (s2 >= base) {
+            s2 -= base;
+        }
+    } else if (input.len < 16) {
+        for (input) |b| {
+            s1 +%= b;
+            s2 +%= s1;
+        }
+        if (s1 >= base) {
+            s1 -= base;
+        }
+
+        s2 %= base;
+    } else {
+        const n = nmax / 16; // note: 16 | nmax
+
+        var i: usize = 0;
+
+        while (i + nmax <= input.len) {
+            var rounds: usize = 0;
+            while (rounds < n) : (rounds += 1) {
+                comptime var j: usize = 0;
+                inline while (j < 16) : (j += 1) {
+                    s1 +%= input[i + j];
+                    s2 +%= s1;
+                }
+                i += 16;
+            }
+
+            s1 %= base;
+            s2 %= base;
+        }
+
+        if (i < input.len) {
+            while (i + 16 <= input.len) : (i += 16) {
+                comptime var j: usize = 0;
+                inline while (j < 16) : (j += 1) {
+                    s1 +%= input[i + j];
+                    s2 +%= s1;
+                }
+            }
+            while (i < input.len) : (i += 1) {
+                s1 +%= input[i];
+                s2 +%= s1;
+            }
+
+            s1 %= base;
+            s2 %= base;
+        }
+    }
+
+    return s1 | (s2 << 16);
+}
+
+pub fn update(a: *Adler32, input: []const u8) void {
+    a.adler = permute(a.adler, input);
+}
+
+pub fn hash(input: []const u8) u32 {
+    return permute(1, input);
+}
+
+test "sanity" {
+    try testing.expectEqual(@as(u32, 0x620062), hash("a"));
+    try testing.expectEqual(@as(u32, 0xbc002ed), hash("example"));
+}
+
+test "long" {
+    const long1 = [_]u8{1} ** 1024;
+    try testing.expectEqual(@as(u32, 0x06780401), hash(long1[0..]));
+
+    const long2 = [_]u8{1} ** 1025;
+    try testing.expectEqual(@as(u32, 0x0a7a0402), hash(long2[0..]));
+}
+
+test "very long" {
+    const long = [_]u8{1} ** 5553;
+    try testing.expectEqual(@as(u32, 0x707f15b2), hash(long[0..]));
+}
+
+test "very long with variation" {
+    const long = comptime blk: {
+        @setEvalBranchQuota(7000);
+        var result: [6000]u8 = undefined;
+
+        var i: usize = 0;
+        while (i < result.len) : (i += 1) {
+            result[i] = @as(u8, @truncate(i));
+        }
+
+        break :blk result;
+    };
+
+    try testing.expectEqual(@as(u32, 0x5af38d6e), hash(long[0..]));
+}
diff --git a/lib/std/hash/adler.zig b/lib/std/hash/adler.zig
deleted file mode 100644
index 52f7b2691a..0000000000
--- a/lib/std/hash/adler.zig
+++ /dev/null
@@ -1,134 +0,0 @@
-// Adler32 checksum.
-//
-// https://tools.ietf.org/html/rfc1950#section-9
-// https://github.com/madler/zlib/blob/master/adler32.c
-
-const std = @import("std");
-const testing = std.testing;
-
-pub const Adler32 = struct {
-    const base = 65521;
-    const nmax = 5552;
-
-    adler: u32,
-
-    pub fn init() Adler32 {
-        return Adler32{ .adler = 1 };
-    }
-
-    // This fast variant is taken from zlib. It reduces the required modulos and unrolls longer
-    // buffer inputs and should be much quicker.
-    pub fn update(self: *Adler32, input: []const u8) void {
-        var s1 = self.adler & 0xffff;
-        var s2 = (self.adler >> 16) & 0xffff;
-
-        if (input.len == 1) {
-            s1 +%= input[0];
-            if (s1 >= base) {
-                s1 -= base;
-            }
-            s2 +%= s1;
-            if (s2 >= base) {
-                s2 -= base;
-            }
-        } else if (input.len < 16) {
-            for (input) |b| {
-                s1 +%= b;
-                s2 +%= s1;
-            }
-            if (s1 >= base) {
-                s1 -= base;
-            }
-
-            s2 %= base;
-        } else {
-            const n = nmax / 16; // note: 16 | nmax
-
-            var i: usize = 0;
-
-            while (i + nmax <= input.len) {
-                var rounds: usize = 0;
-                while (rounds < n) : (rounds += 1) {
-                    comptime var j: usize = 0;
-                    inline while (j < 16) : (j += 1) {
-                        s1 +%= input[i + j];
-                        s2 +%= s1;
-                    }
-                    i += 16;
-                }
-
-                s1 %= base;
-                s2 %= base;
-            }
-
-            if (i < input.len) {
-                while (i + 16 <= input.len) : (i += 16) {
-                    comptime var j: usize = 0;
-                    inline while (j < 16) : (j += 1) {
-                        s1 +%= input[i + j];
-                        s2 +%= s1;
-                    }
-                }
-                while (i < input.len) : (i += 1) {
-                    s1 +%= input[i];
-                    s2 +%= s1;
-                }
-
-                s1 %= base;
-                s2 %= base;
-            }
-        }
-
-        self.adler = s1 | (s2 << 16);
-    }
-
-    pub fn final(self: *Adler32) u32 {
-        return self.adler;
-    }
-
-    pub fn hash(input: []const u8) u32 {
-        var c = Adler32.init();
-        c.update(input);
-        return c.final();
-    }
-};
-
-test "adler32 sanity" {
-    try testing.expectEqual(@as(u32, 0x620062), Adler32.hash("a"));
-    try testing.expectEqual(@as(u32, 0xbc002ed), Adler32.hash("example"));
-}
-
-test "adler32 long" {
-    const long1 = [_]u8{1} ** 1024;
-    try testing.expectEqual(@as(u32, 0x06780401), Adler32.hash(long1[0..]));
-
-    const long2 = [_]u8{1} ** 1025;
-    try testing.expectEqual(@as(u32, 0x0a7a0402), Adler32.hash(long2[0..]));
-}
-
-test "adler32 very long" {
-    const long = [_]u8{1} ** 5553;
-    try testing.expectEqual(@as(u32, 0x707f15b2), Adler32.hash(long[0..]));
-}
-
-test "adler32 very long with variation" {
-    const long = comptime blk: {
-        @setEvalBranchQuota(7000);
-        var result: [6000]u8 = undefined;
-
-        var i: usize = 0;
-        while (i < result.len) : (i += 1) {
-            result[i] = @as(u8, @truncate(i));
-        }
-
-        break :blk result;
-    };
-
-    try testing.expectEqual(@as(u32, 0x5af38d6e), std.hash.Adler32.hash(long[0..]));
-}
-
-const verify = @import("verify.zig");
-
-test "adler32 iterative" {
-    try verify.iterativeApi(Adler32);
-}
diff --git a/lib/std/hash/verify.zig b/lib/std/hash/verify.zig
index 61f501a881..a96a36c050 100644
--- a/lib/std/hash/verify.zig
+++ b/lib/std/hash/verify.zig
@@ -45,7 +45,7 @@ pub fn smhasher(comptime hash_fn: anytype) u32 {
 
 pub fn iterativeApi(comptime Hash: anytype) !void {
     // Sum(1..32) = 528
-    var buf: [528]u8 = [_]u8{0} ** 528;
+    var buf: [528]u8 = @splat(0);
     var len: usize = 0;
     const seed = 0;
 
diff --git a/lib/std/http/Client.zig b/lib/std/http/Client.zig
index 838411bebc..20f6018e45 100644
--- a/lib/std/http/Client.zig
+++ b/lib/std/http/Client.zig
@@ -405,13 +405,8 @@ pub const RequestTransfer = union(enum) {
 
 /// The decompressor for response messages.
 pub const Compression = union(enum) {
-    pub const DeflateDecompressor = std.compress.zlib.Decompressor(Request.TransferReader);
-    pub const GzipDecompressor = std.compress.gzip.Decompressor(Request.TransferReader);
-    // https://github.com/ziglang/zig/issues/18937
-    //pub const ZstdDecompressor = std.compress.zstd.DecompressStream(Request.TransferReader, .{});
-
-    deflate: DeflateDecompressor,
-    gzip: GzipDecompressor,
+    //deflate: std.compress.flate.Decompress,
+    //gzip: std.compress.flate.Decompress,
     // https://github.com/ziglang/zig/issues/18937
     //zstd: ZstdDecompressor,
     none: void,
@@ -1079,12 +1074,10 @@ pub const Request = struct {
                     switch (req.response.transfer_compression) {
                         .identity => req.response.compression = .none,
                         .compress, .@"x-compress" => return error.CompressionUnsupported,
-                        .deflate => req.response.compression = .{
-                            .deflate = std.compress.zlib.decompressor(req.transferReader()),
-                        },
-                        .gzip, .@"x-gzip" => req.response.compression = .{
-                            .gzip = std.compress.gzip.decompressor(req.transferReader()),
-                        },
+                        // I'm about to upstream my http.Client rewrite
+                        .deflate => return error.CompressionUnsupported,
+                        // I'm about to upstream my http.Client rewrite
+                        .gzip, .@"x-gzip" => return error.CompressionUnsupported,
                         // https://github.com/ziglang/zig/issues/18937
                         //.zstd => req.response.compression = .{
                         //    .zstd = std.compress.zstd.decompressStream(req.client.allocator, req.transferReader()),
@@ -1110,8 +1103,9 @@ pub const Request = struct {
     /// Reads data from the response body. Must be called after `wait`.
     pub fn read(req: *Request, buffer: []u8) ReadError!usize {
         const out_index = switch (req.response.compression) {
-            .deflate => |*deflate| deflate.read(buffer) catch return error.DecompressionFailure,
-            .gzip => |*gzip| gzip.read(buffer) catch return error.DecompressionFailure,
+            // I'm about to upstream my http client rewrite
+            //.deflate => |*deflate| deflate.readSlice(buffer) catch return error.DecompressionFailure,
+            //.gzip => |*gzip| gzip.read(buffer) catch return error.DecompressionFailure,
             // https://github.com/ziglang/zig/issues/18937
             //.zstd => |*zstd| zstd.read(buffer) catch return error.DecompressionFailure,
             else => try req.transferRead(buffer),
diff --git a/lib/std/http/Server.zig b/lib/std/http/Server.zig
index 886aed72dc..7ec5d5c11f 100644
--- a/lib/std/http/Server.zig
+++ b/lib/std/http/Server.zig
@@ -130,8 +130,8 @@ pub const Request = struct {
         pub const DeflateDecompressor = std.compress.zlib.Decompressor(std.io.AnyReader);
         pub const GzipDecompressor = std.compress.gzip.Decompressor(std.io.AnyReader);
 
-        deflate: DeflateDecompressor,
-        gzip: GzipDecompressor,
+        deflate: std.compress.flate.Decompress,
+        gzip: std.compress.flate.Decompress,
         zstd: std.compress.zstd.Decompress,
         none: void,
     };
diff --git a/lib/std/net.zig b/lib/std/net.zig
index ac851059d2..38c0785194 100644
--- a/lib/std/net.zig
+++ b/lib/std/net.zig
@@ -1973,12 +1973,13 @@ pub const Stream = struct {
 
             fn stream(io_r: *Io.Reader, io_w: *Io.Writer, limit: Io.Limit) Io.Reader.StreamError!usize {
                 const dest = limit.slice(try io_w.writableSliceGreedy(1));
-                const n = try readVec(io_r, &.{dest});
+                var bufs: [1][]u8 = .{dest};
+                const n = try readVec(io_r, &bufs);
                 io_w.advance(n);
                 return n;
             }
 
-            fn readVec(io_r: *std.Io.Reader, data: []const []u8) Io.Reader.Error!usize {
+            fn readVec(io_r: *std.Io.Reader, data: [][]u8) Io.Reader.Error!usize {
                 const r: *Reader = @alignCast(@fieldParentPtr("interface_state", io_r));
                 var iovecs: [max_buffers_len]windows.ws2_32.WSABUF = undefined;
                 const bufs_n, const data_size = try io_r.writableVectorWsa(&iovecs, data);
diff --git a/lib/std/zip.zig b/lib/std/zip.zig
index e181bc1f65..e1e8e04a36 100644
--- a/lib/std/zip.zig
+++ b/lib/std/zip.zig
@@ -5,11 +5,11 @@
 
 const builtin = @import("builtin");
 const std = @import("std");
-const testing = std.testing;
-
-pub const testutil = @import("zip/test.zig");
-const File = testutil.File;
-const FileStore = testutil.FileStore;
+const File = std.fs.File;
+const is_le = builtin.target.cpu.arch.endian() == .little;
+const Writer = std.Io.Writer;
+const Reader = std.Io.Reader;
+const flate = std.compress.flate;
 
 pub const CompressionMethod = enum(u16) {
     store = 0,
@@ -95,102 +95,116 @@ pub const EndRecord = extern struct {
     central_directory_size: u32 align(1),
     central_directory_offset: u32 align(1),
     comment_len: u16 align(1),
+
     pub fn need_zip64(self: EndRecord) bool {
         return isMaxInt(self.record_count_disk) or
             isMaxInt(self.record_count_total) or
             isMaxInt(self.central_directory_size) or
             isMaxInt(self.central_directory_offset);
     }
+
+    pub const FindBufferError = error{ ZipNoEndRecord, ZipTruncated };
+
+    /// TODO audit this logic
+    pub fn findBuffer(buffer: []const u8) FindBufferError!EndRecord {
+        const pos = std.mem.lastIndexOf(u8, buffer, &end_record_sig) orelse return error.ZipNoEndRecord;
+        if (pos + @sizeOf(EndRecord) > buffer.len) return error.EndOfStream;
+        const record_ptr: *EndRecord = @ptrCast(buffer[pos..][0..@sizeOf(EndRecord)]);
+        var record = record_ptr.*;
+        if (!is_le) std.mem.byteSwapAllFields(EndRecord, &record);
+        return record;
+    }
+
+    pub const FindFileError = File.GetEndPosError || File.SeekError || File.ReadError || error{
+        ZipNoEndRecord,
+        EndOfStream,
+        ReadFailed,
+    };
+
+    pub fn findFile(fr: *File.Reader) FindFileError!EndRecord {
+        const end_pos = try fr.getSize();
+
+        var buf: [@sizeOf(EndRecord) + std.math.maxInt(u16)]u8 = undefined;
+        const record_len_max = @min(end_pos, buf.len);
+        var loaded_len: u32 = 0;
+        var comment_len: u16 = 0;
+        while (true) {
+            const record_len: u32 = @as(u32, comment_len) + @sizeOf(EndRecord);
+            if (record_len > record_len_max)
+                return error.ZipNoEndRecord;
+
+            if (record_len > loaded_len) {
+                const new_loaded_len = @min(loaded_len + 300, record_len_max);
+                const read_len = new_loaded_len - loaded_len;
+
+                try fr.seekTo(end_pos - @as(u64, new_loaded_len));
+                const read_buf: []u8 = buf[buf.len - new_loaded_len ..][0..read_len];
+                fr.interface.readSliceAll(read_buf) catch |err| switch (err) {
+                    error.ReadFailed => return fr.err.?,
+                    error.EndOfStream => return error.EndOfStream,
+                };
+                loaded_len = new_loaded_len;
+            }
+
+            const record_bytes = buf[buf.len - record_len ..][0..@sizeOf(EndRecord)];
+            if (std.mem.eql(u8, record_bytes[0..4], &end_record_sig) and
+                std.mem.readInt(u16, record_bytes[20..22], .little) == comment_len)
+            {
+                const record: *align(1) EndRecord = @ptrCast(record_bytes.ptr);
+                if (!is_le) std.mem.byteSwapAllFields(EndRecord, record);
+                return record.*;
+            }
+
+            if (comment_len == std.math.maxInt(u16))
+                return error.ZipNoEndRecord;
+            comment_len += 1;
+        }
+    }
 };
 
-/// Find and return the end record for the given seekable zip stream.
-/// Note that `seekable_stream` must be an instance of `std.io.SeekableStream` and
-/// its context must also have a `.reader()` method that returns an instance of
-/// `std.io.GenericReader`.
-pub fn findEndRecord(seekable_stream: anytype, stream_len: u64) !EndRecord {
-    var buf: [@sizeOf(EndRecord) + std.math.maxInt(u16)]u8 = undefined;
-    const record_len_max = @min(stream_len, buf.len);
-    var loaded_len: u32 = 0;
+pub const Decompress = struct {
+    interface: Reader,
+    state: union {
+        inflate: flate.Decompress,
+        store: *Reader,
+    },
 
-    var comment_len: u16 = 0;
-    while (true) {
-        const record_len: u32 = @as(u32, comment_len) + @sizeOf(EndRecord);
-        if (record_len > record_len_max)
-            return error.ZipNoEndRecord;
-
-        if (record_len > loaded_len) {
-            const new_loaded_len = @min(loaded_len + 300, record_len_max);
-            const read_len = new_loaded_len - loaded_len;
-
-            try seekable_stream.seekTo(stream_len - @as(u64, new_loaded_len));
-            const read_buf: []u8 = buf[buf.len - new_loaded_len ..][0..read_len];
-            const len = try (if (@TypeOf(seekable_stream.context) == std.fs.File) seekable_stream.context.deprecatedReader() else seekable_stream.context.reader()).readAll(read_buf);
-            if (len != read_len)
-                return error.ZipTruncated;
-            loaded_len = new_loaded_len;
-        }
-
-        const record_bytes = buf[buf.len - record_len ..][0..@sizeOf(EndRecord)];
-        if (std.mem.eql(u8, record_bytes[0..4], &end_record_sig) and
-            std.mem.readInt(u16, record_bytes[20..22], .little) == comment_len)
-        {
-            const record: *align(1) EndRecord = @ptrCast(record_bytes.ptr);
-            if (builtin.target.cpu.arch.endian() != .little) {
-                std.mem.byteSwapAllFields(@TypeOf(record.*), record);
-            }
-            return record.*;
-        }
-
-        if (comment_len == std.math.maxInt(u16))
-            return error.ZipNoEndRecord;
-        comment_len += 1;
+    pub fn init(reader: *Reader, method: CompressionMethod, buffer: []u8) Reader {
+        return switch (method) {
+            .store => .{
+                .state = .{ .store = reader },
+                .interface = .{
+                    .context = undefined,
+                    .vtable = &.{ .stream = streamStore },
+                    .buffer = buffer,
+                    .end = 0,
+                    .seek = 0,
+                },
+            },
+            .deflate => .{
+                .state = .{ .inflate = .init(reader, .raw) },
+                .interface = .{
+                    .context = undefined,
+                    .vtable = &.{ .stream = streamDeflate },
+                    .buffer = buffer,
+                    .end = 0,
+                    .seek = 0,
+                },
+            },
+            else => unreachable,
+        };
     }
-}
 
-/// Decompresses the given data from `reader` into `writer`.  Stops early if more
-/// than `uncompressed_size` bytes are processed and verifies that exactly that
-/// number of bytes are decompressed.  Returns the CRC-32 of the uncompressed data.
-/// `writer` can be anything with a `writeAll(self: *Self, chunk: []const u8) anyerror!void` method.
-pub fn decompress(
-    method: CompressionMethod,
-    uncompressed_size: u64,
-    reader: anytype,
-    writer: anytype,
-) !u32 {
-    var hash = std.hash.Crc32.init();
-
-    var total_uncompressed: u64 = 0;
-    switch (method) {
-        .store => {
-            var buf: [4096]u8 = undefined;
-            while (true) {
-                const len = try reader.read(&buf);
-                if (len == 0) break;
-                try writer.writeAll(buf[0..len]);
-                hash.update(buf[0..len]);
-                total_uncompressed += @intCast(len);
-            }
-        },
-        .deflate => {
-            var br = std.io.bufferedReader(reader);
-            var decompressor = std.compress.flate.decompressor(br.reader());
-            while (try decompressor.next()) |chunk| {
-                try writer.writeAll(chunk);
-                hash.update(chunk);
-                total_uncompressed += @intCast(chunk.len);
-                if (total_uncompressed > uncompressed_size)
-                    return error.ZipUncompressSizeTooSmall;
-            }
-            if (br.end != br.start)
-                return error.ZipDeflateTruncated;
-        },
-        _ => return error.UnsupportedCompressionMethod,
+    fn streamStore(r: *Reader, w: *Writer, limit: std.io.Limit) Reader.StreamError!usize {
+        const d: *Decompress = @fieldParentPtr("interface", r);
+        return d.store.read(w, limit);
     }
-    if (total_uncompressed != uncompressed_size)
-        return error.ZipUncompressSizeMismatch;
 
-    return hash.final();
-}
+    fn streamDeflate(r: *Reader, w: *Writer, limit: std.io.Limit) Reader.StreamError!usize {
+        const d: *Decompress = @fieldParentPtr("interface", r);
+        return flate.Decompress.read(&d.inflate, w, limit);
+    }
+};
 
 fn isBadFilename(filename: []const u8) bool {
     if (filename.len == 0 or filename[0] == '/')
@@ -253,319 +267,337 @@ fn readZip64FileExtents(comptime T: type, header: T, extents: *FileExtents, data
     }
 }
 
-pub fn Iterator(comptime SeekableStream: type) type {
-    return struct {
-        stream: SeekableStream,
+pub const Iterator = struct {
+    input: *File.Reader,
 
-        cd_record_count: u64,
-        cd_zip_offset: u64,
-        cd_size: u64,
+    cd_record_count: u64,
+    cd_zip_offset: u64,
+    cd_size: u64,
 
-        cd_record_index: u64 = 0,
-        cd_record_offset: u64 = 0,
+    cd_record_index: u64 = 0,
+    cd_record_offset: u64 = 0,
 
-        const Self = @This();
+    pub fn init(input: *File.Reader) !Iterator {
+        const end_record = try EndRecord.findFile(input);
 
-        pub fn init(stream: SeekableStream) !Self {
-            const stream_len = try stream.getEndPos();
+        if (!isMaxInt(end_record.record_count_disk) and end_record.record_count_disk > end_record.record_count_total)
+            return error.ZipDiskRecordCountTooLarge;
 
-            const end_record = try findEndRecord(stream, stream_len);
+        if (end_record.disk_number != 0 or end_record.central_directory_disk_number != 0)
+            return error.ZipMultiDiskUnsupported;
 
-            if (!isMaxInt(end_record.record_count_disk) and end_record.record_count_disk > end_record.record_count_total)
-                return error.ZipDiskRecordCountTooLarge;
-
-            if (end_record.disk_number != 0 or end_record.central_directory_disk_number != 0)
+        {
+            const counts_valid = !isMaxInt(end_record.record_count_disk) and !isMaxInt(end_record.record_count_total);
+            if (counts_valid and end_record.record_count_disk != end_record.record_count_total)
                 return error.ZipMultiDiskUnsupported;
-
-            {
-                const counts_valid = !isMaxInt(end_record.record_count_disk) and !isMaxInt(end_record.record_count_total);
-                if (counts_valid and end_record.record_count_disk != end_record.record_count_total)
-                    return error.ZipMultiDiskUnsupported;
-            }
-
-            var result = Self{
-                .stream = stream,
-                .cd_record_count = end_record.record_count_total,
-                .cd_zip_offset = end_record.central_directory_offset,
-                .cd_size = end_record.central_directory_size,
-            };
-            if (!end_record.need_zip64()) return result;
-
-            const locator_end_offset: u64 = @as(u64, end_record.comment_len) + @sizeOf(EndRecord) + @sizeOf(EndLocator64);
-            if (locator_end_offset > stream_len)
-                return error.ZipTruncated;
-            try stream.seekTo(stream_len - locator_end_offset);
-            const locator = try (if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()).readStructEndian(EndLocator64, .little);
-            if (!std.mem.eql(u8, &locator.signature, &end_locator64_sig))
-                return error.ZipBadLocatorSig;
-            if (locator.zip64_disk_count != 0)
-                return error.ZipUnsupportedZip64DiskCount;
-            if (locator.total_disk_count != 1)
-                return error.ZipMultiDiskUnsupported;
-
-            try stream.seekTo(locator.record_file_offset);
-
-            const record64 = try (if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()).readStructEndian(EndRecord64, .little);
-
-            if (!std.mem.eql(u8, &record64.signature, &end_record64_sig))
-                return error.ZipBadEndRecord64Sig;
-
-            if (record64.end_record_size < @sizeOf(EndRecord64) - 12)
-                return error.ZipEndRecord64SizeTooSmall;
-            if (record64.end_record_size > @sizeOf(EndRecord64) - 12)
-                return error.ZipEndRecord64UnhandledExtraData;
-
-            if (record64.version_needed_to_extract > 45)
-                return error.ZipUnsupportedVersion;
-
-            {
-                const is_multidisk = record64.disk_number != 0 or
-                    record64.central_directory_disk_number != 0 or
-                    record64.record_count_disk != record64.record_count_total;
-                if (is_multidisk)
-                    return error.ZipMultiDiskUnsupported;
-            }
-
-            if (isMaxInt(end_record.record_count_total)) {
-                result.cd_record_count = record64.record_count_total;
-            } else if (end_record.record_count_total != record64.record_count_total)
-                return error.Zip64RecordCountTotalMismatch;
-
-            if (isMaxInt(end_record.central_directory_offset)) {
-                result.cd_zip_offset = record64.central_directory_offset;
-            } else if (end_record.central_directory_offset != record64.central_directory_offset)
-                return error.Zip64CentralDirectoryOffsetMismatch;
-
-            if (isMaxInt(end_record.central_directory_size)) {
-                result.cd_size = record64.central_directory_size;
-            } else if (end_record.central_directory_size != record64.central_directory_size)
-                return error.Zip64CentralDirectorySizeMismatch;
-
-            return result;
         }
 
-        pub fn next(self: *Self) !?Entry {
-            if (self.cd_record_index == self.cd_record_count) {
-                if (self.cd_record_offset != self.cd_size)
-                    return if (self.cd_size > self.cd_record_offset)
-                        error.ZipCdOversized
-                    else
-                        error.ZipCdUndersized;
-
-                return null;
-            }
-
-            const header_zip_offset = self.cd_zip_offset + self.cd_record_offset;
-            try self.stream.seekTo(header_zip_offset);
-            const header = try (if (@TypeOf(self.stream.context) == std.fs.File) self.stream.context.deprecatedReader() else self.stream.context.reader()).readStructEndian(CentralDirectoryFileHeader, .little);
-            if (!std.mem.eql(u8, &header.signature, &central_file_header_sig))
-                return error.ZipBadCdOffset;
-
-            self.cd_record_index += 1;
-            self.cd_record_offset += @sizeOf(CentralDirectoryFileHeader) + header.filename_len + header.extra_len + header.comment_len;
-
-            // Note: checking the version_needed_to_extract doesn't seem to be helpful, i.e. the zip file
-            // at https://github.com/ninja-build/ninja/releases/download/v1.12.0/ninja-linux.zip
-            // has an undocumented version 788 but extracts just fine.
-
-            if (header.flags.encrypted)
-                return error.ZipEncryptionUnsupported;
-            // TODO: check/verify more flags
-            if (header.disk_number != 0)
-                return error.ZipMultiDiskUnsupported;
-
-            var extents: FileExtents = .{
-                .uncompressed_size = header.uncompressed_size,
-                .compressed_size = header.compressed_size,
-                .local_file_header_offset = header.local_file_header_offset,
-            };
-
-            if (header.extra_len > 0) {
-                var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
-                const extra = extra_buf[0..header.extra_len];
-
-                {
-                    try self.stream.seekTo(header_zip_offset + @sizeOf(CentralDirectoryFileHeader) + header.filename_len);
-                    const len = try (if (@TypeOf(self.stream.context) == std.fs.File) self.stream.context.deprecatedReader() else self.stream.context.reader()).readAll(extra);
-                    if (len != extra.len)
-                        return error.ZipTruncated;
-                }
-
-                var extra_offset: usize = 0;
-                while (extra_offset + 4 <= extra.len) {
-                    const header_id = std.mem.readInt(u16, extra[extra_offset..][0..2], .little);
-                    const data_size = std.mem.readInt(u16, extra[extra_offset..][2..4], .little);
-                    const end = extra_offset + 4 + data_size;
-                    if (end > extra.len)
-                        return error.ZipBadExtraFieldSize;
-                    const data = extra[extra_offset + 4 .. end];
-                    switch (@as(ExtraHeader, @enumFromInt(header_id))) {
-                        .zip64_info => try readZip64FileExtents(CentralDirectoryFileHeader, header, &extents, data),
-                        else => {}, // ignore
-                    }
-                    extra_offset = end;
-                }
-            }
-
-            return .{
-                .version_needed_to_extract = header.version_needed_to_extract,
-                .flags = header.flags,
-                .compression_method = header.compression_method,
-                .last_modification_time = header.last_modification_time,
-                .last_modification_date = header.last_modification_date,
-                .header_zip_offset = header_zip_offset,
-                .crc32 = header.crc32,
-                .filename_len = header.filename_len,
-                .compressed_size = extents.compressed_size,
-                .uncompressed_size = extents.uncompressed_size,
-                .file_offset = extents.local_file_header_offset,
-            };
-        }
-
-        pub const Entry = struct {
-            version_needed_to_extract: u16,
-            flags: GeneralPurposeFlags,
-            compression_method: CompressionMethod,
-            last_modification_time: u16,
-            last_modification_date: u16,
-            header_zip_offset: u64,
-            crc32: u32,
-            filename_len: u32,
-            compressed_size: u64,
-            uncompressed_size: u64,
-            file_offset: u64,
-
-            pub fn extract(
-                self: Entry,
-                stream: SeekableStream,
-                options: ExtractOptions,
-                filename_buf: []u8,
-                dest: std.fs.Dir,
-            ) !u32 {
-                if (filename_buf.len < self.filename_len)
-                    return error.ZipInsufficientBuffer;
-                const filename = filename_buf[0..self.filename_len];
-
-                try stream.seekTo(self.header_zip_offset + @sizeOf(CentralDirectoryFileHeader));
-
-                {
-                    const len = try (if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()).readAll(filename);
-                    if (len != filename.len)
-                        return error.ZipBadFileOffset;
-                }
-
-                const local_data_header_offset: u64 = local_data_header_offset: {
-                    const local_header = blk: {
-                        try stream.seekTo(self.file_offset);
-                        break :blk try (if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()).readStructEndian(LocalFileHeader, .little);
-                    };
-                    if (!std.mem.eql(u8, &local_header.signature, &local_file_header_sig))
-                        return error.ZipBadFileOffset;
-                    if (local_header.version_needed_to_extract != self.version_needed_to_extract)
-                        return error.ZipMismatchVersionNeeded;
-                    if (local_header.last_modification_time != self.last_modification_time)
-                        return error.ZipMismatchModTime;
-                    if (local_header.last_modification_date != self.last_modification_date)
-                        return error.ZipMismatchModDate;
-
-                    if (@as(u16, @bitCast(local_header.flags)) != @as(u16, @bitCast(self.flags)))
-                        return error.ZipMismatchFlags;
-                    if (local_header.crc32 != 0 and local_header.crc32 != self.crc32)
-                        return error.ZipMismatchCrc32;
-                    var extents: FileExtents = .{
-                        .uncompressed_size = local_header.uncompressed_size,
-                        .compressed_size = local_header.compressed_size,
-                        .local_file_header_offset = 0,
-                    };
-                    if (local_header.extra_len > 0) {
-                        var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
-                        const extra = extra_buf[0..local_header.extra_len];
-
-                        {
-                            try stream.seekTo(self.file_offset + @sizeOf(LocalFileHeader) + local_header.filename_len);
-                            const len = try (if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()).readAll(extra);
-                            if (len != extra.len)
-                                return error.ZipTruncated;
-                        }
-
-                        var extra_offset: usize = 0;
-                        while (extra_offset + 4 <= local_header.extra_len) {
-                            const header_id = std.mem.readInt(u16, extra[extra_offset..][0..2], .little);
-                            const data_size = std.mem.readInt(u16, extra[extra_offset..][2..4], .little);
-                            const end = extra_offset + 4 + data_size;
-                            if (end > local_header.extra_len)
-                                return error.ZipBadExtraFieldSize;
-                            const data = extra[extra_offset + 4 .. end];
-                            switch (@as(ExtraHeader, @enumFromInt(header_id))) {
-                                .zip64_info => try readZip64FileExtents(LocalFileHeader, local_header, &extents, data),
-                                else => {}, // ignore
-                            }
-                            extra_offset = end;
-                        }
-                    }
-
-                    if (extents.compressed_size != 0 and
-                        extents.compressed_size != self.compressed_size)
-                        return error.ZipMismatchCompLen;
-                    if (extents.uncompressed_size != 0 and
-                        extents.uncompressed_size != self.uncompressed_size)
-                        return error.ZipMismatchUncompLen;
-
-                    if (local_header.filename_len != self.filename_len)
-                        return error.ZipMismatchFilenameLen;
-
-                    break :local_data_header_offset @as(u64, local_header.filename_len) +
-                        @as(u64, local_header.extra_len);
-                };
-
-                if (isBadFilename(filename))
-                    return error.ZipBadFilename;
-
-                if (options.allow_backslashes) {
-                    std.mem.replaceScalar(u8, filename, '\\', '/');
-                } else {
-                    if (std.mem.indexOfScalar(u8, filename, '\\')) |_|
-                        return error.ZipFilenameHasBackslash;
-                }
-
-                // All entries that end in '/' are directories
-                if (filename[filename.len - 1] == '/') {
-                    if (self.uncompressed_size != 0)
-                        return error.ZipBadDirectorySize;
-                    try dest.makePath(filename[0 .. filename.len - 1]);
-                    return std.hash.Crc32.hash(&.{});
-                }
-
-                const out_file = blk: {
-                    if (std.fs.path.dirname(filename)) |dirname| {
-                        var parent_dir = try dest.makeOpenPath(dirname, .{});
-                        defer parent_dir.close();
-
-                        const basename = std.fs.path.basename(filename);
-                        break :blk try parent_dir.createFile(basename, .{ .exclusive = true });
-                    }
-                    break :blk try dest.createFile(filename, .{ .exclusive = true });
-                };
-                defer out_file.close();
-                const local_data_file_offset: u64 =
-                    @as(u64, self.file_offset) +
-                    @as(u64, @sizeOf(LocalFileHeader)) +
-                    local_data_header_offset;
-                try stream.seekTo(local_data_file_offset);
-                var limited_reader = std.io.limitedReader((if (@TypeOf(stream.context) == std.fs.File) stream.context.deprecatedReader() else stream.context.reader()), self.compressed_size);
-                const crc = try decompress(
-                    self.compression_method,
-                    self.uncompressed_size,
-                    limited_reader.reader(),
-                    out_file.deprecatedWriter(),
-                );
-                if (limited_reader.bytes_left != 0)
-                    return error.ZipDecompressTruncated;
-                return crc;
-            }
+        var result: Iterator = .{
+            .input = input,
+            .cd_record_count = end_record.record_count_total,
+            .cd_zip_offset = end_record.central_directory_offset,
+            .cd_size = end_record.central_directory_size,
         };
+        if (!end_record.need_zip64()) return result;
+
+        const locator_end_offset: u64 = @as(u64, end_record.comment_len) + @sizeOf(EndRecord) + @sizeOf(EndLocator64);
+        const stream_len = try input.getSize();
+
+        if (locator_end_offset > stream_len)
+            return error.ZipTruncated;
+        try input.seekTo(stream_len - locator_end_offset);
+        const locator = input.interface.takeStruct(EndLocator64, .little) catch |err| switch (err) {
+            error.ReadFailed => return input.err.?,
+            error.EndOfStream => return error.EndOfStream,
+        };
+        if (!std.mem.eql(u8, &locator.signature, &end_locator64_sig))
+            return error.ZipBadLocatorSig;
+        if (locator.zip64_disk_count != 0)
+            return error.ZipUnsupportedZip64DiskCount;
+        if (locator.total_disk_count != 1)
+            return error.ZipMultiDiskUnsupported;
+
+        try input.seekTo(locator.record_file_offset);
+
+        const record64 = input.interface.takeStruct(EndRecord64, .little) catch |err| switch (err) {
+            error.ReadFailed => return input.err.?,
+            error.EndOfStream => return error.EndOfStream,
+        };
+
+        if (!std.mem.eql(u8, &record64.signature, &end_record64_sig))
+            return error.ZipBadEndRecord64Sig;
+
+        if (record64.end_record_size < @sizeOf(EndRecord64) - 12)
+            return error.ZipEndRecord64SizeTooSmall;
+        if (record64.end_record_size > @sizeOf(EndRecord64) - 12)
+            return error.ZipEndRecord64UnhandledExtraData;
+
+        if (record64.version_needed_to_extract > 45)
+            return error.ZipUnsupportedVersion;
+
+        {
+            const is_multidisk = record64.disk_number != 0 or
+                record64.central_directory_disk_number != 0 or
+                record64.record_count_disk != record64.record_count_total;
+            if (is_multidisk)
+                return error.ZipMultiDiskUnsupported;
+        }
+
+        if (isMaxInt(end_record.record_count_total)) {
+            result.cd_record_count = record64.record_count_total;
+        } else if (end_record.record_count_total != record64.record_count_total)
+            return error.Zip64RecordCountTotalMismatch;
+
+        if (isMaxInt(end_record.central_directory_offset)) {
+            result.cd_zip_offset = record64.central_directory_offset;
+        } else if (end_record.central_directory_offset != record64.central_directory_offset)
+            return error.Zip64CentralDirectoryOffsetMismatch;
+
+        if (isMaxInt(end_record.central_directory_size)) {
+            result.cd_size = record64.central_directory_size;
+        } else if (end_record.central_directory_size != record64.central_directory_size)
+            return error.Zip64CentralDirectorySizeMismatch;
+
+        return result;
+    }
+
+    pub fn next(self: *Iterator) !?Entry {
+        if (self.cd_record_index == self.cd_record_count) {
+            if (self.cd_record_offset != self.cd_size)
+                return if (self.cd_size > self.cd_record_offset)
+                    error.ZipCdOversized
+                else
+                    error.ZipCdUndersized;
+
+            return null;
+        }
+
+        const header_zip_offset = self.cd_zip_offset + self.cd_record_offset;
+        const input = self.input;
+        try input.seekTo(header_zip_offset);
+        const header = input.interface.takeStruct(CentralDirectoryFileHeader, .little) catch |err| switch (err) {
+            error.ReadFailed => return input.err.?,
+            error.EndOfStream => return error.EndOfStream,
+        };
+        if (!std.mem.eql(u8, &header.signature, &central_file_header_sig))
+            return error.ZipBadCdOffset;
+
+        self.cd_record_index += 1;
+        self.cd_record_offset += @sizeOf(CentralDirectoryFileHeader) + header.filename_len + header.extra_len + header.comment_len;
+
+        // Note: checking the version_needed_to_extract doesn't seem to be helpful, i.e. the zip file
+        // at https://github.com/ninja-build/ninja/releases/download/v1.12.0/ninja-linux.zip
+        // has an undocumented version 788 but extracts just fine.
+
+        if (header.flags.encrypted)
+            return error.ZipEncryptionUnsupported;
+        // TODO: check/verify more flags
+        if (header.disk_number != 0)
+            return error.ZipMultiDiskUnsupported;
+
+        var extents: FileExtents = .{
+            .uncompressed_size = header.uncompressed_size,
+            .compressed_size = header.compressed_size,
+            .local_file_header_offset = header.local_file_header_offset,
+        };
+
+        if (header.extra_len > 0) {
+            var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
+            const extra = extra_buf[0..header.extra_len];
+
+            try input.seekTo(header_zip_offset + @sizeOf(CentralDirectoryFileHeader) + header.filename_len);
+            input.interface.readSliceAll(extra) catch |err| switch (err) {
+                error.ReadFailed => return input.err.?,
+                error.EndOfStream => return error.EndOfStream,
+            };
+
+            var extra_offset: usize = 0;
+            while (extra_offset + 4 <= extra.len) {
+                const header_id = std.mem.readInt(u16, extra[extra_offset..][0..2], .little);
+                const data_size = std.mem.readInt(u16, extra[extra_offset..][2..4], .little);
+                const end = extra_offset + 4 + data_size;
+                if (end > extra.len)
+                    return error.ZipBadExtraFieldSize;
+                const data = extra[extra_offset + 4 .. end];
+                switch (@as(ExtraHeader, @enumFromInt(header_id))) {
+                    .zip64_info => try readZip64FileExtents(CentralDirectoryFileHeader, header, &extents, data),
+                    else => {}, // ignore
+                }
+                extra_offset = end;
+            }
+        }
+
+        return .{
+            .version_needed_to_extract = header.version_needed_to_extract,
+            .flags = header.flags,
+            .compression_method = header.compression_method,
+            .last_modification_time = header.last_modification_time,
+            .last_modification_date = header.last_modification_date,
+            .header_zip_offset = header_zip_offset,
+            .crc32 = header.crc32,
+            .filename_len = header.filename_len,
+            .compressed_size = extents.compressed_size,
+            .uncompressed_size = extents.uncompressed_size,
+            .file_offset = extents.local_file_header_offset,
+        };
+    }
+
+    pub const Entry = struct {
+        version_needed_to_extract: u16,
+        flags: GeneralPurposeFlags,
+        compression_method: CompressionMethod,
+        last_modification_time: u16,
+        last_modification_date: u16,
+        header_zip_offset: u64,
+        crc32: u32,
+        filename_len: u32,
+        compressed_size: u64,
+        uncompressed_size: u64,
+        file_offset: u64,
+
+        pub fn extract(
+            self: Entry,
+            stream: *File.Reader,
+            options: ExtractOptions,
+            filename_buf: []u8,
+            dest: std.fs.Dir,
+        ) !void {
+            if (filename_buf.len < self.filename_len)
+                return error.ZipInsufficientBuffer;
+            switch (self.compression_method) {
+                .store, .deflate => {},
+                else => return error.UnsupportedCompressionMethod,
+            }
+            const filename = filename_buf[0..self.filename_len];
+            {
+                try stream.seekTo(self.header_zip_offset + @sizeOf(CentralDirectoryFileHeader));
+                try stream.interface.readSliceAll(filename);
+            }
+
+            const local_data_header_offset: u64 = local_data_header_offset: {
+                const local_header = blk: {
+                    try stream.seekTo(self.file_offset);
+                    break :blk try stream.interface.takeStruct(LocalFileHeader, .little);
+                };
+                if (!std.mem.eql(u8, &local_header.signature, &local_file_header_sig))
+                    return error.ZipBadFileOffset;
+                if (local_header.version_needed_to_extract != self.version_needed_to_extract)
+                    return error.ZipMismatchVersionNeeded;
+                if (local_header.last_modification_time != self.last_modification_time)
+                    return error.ZipMismatchModTime;
+                if (local_header.last_modification_date != self.last_modification_date)
+                    return error.ZipMismatchModDate;
+
+                if (@as(u16, @bitCast(local_header.flags)) != @as(u16, @bitCast(self.flags)))
+                    return error.ZipMismatchFlags;
+                if (local_header.crc32 != 0 and local_header.crc32 != self.crc32)
+                    return error.ZipMismatchCrc32;
+                var extents: FileExtents = .{
+                    .uncompressed_size = local_header.uncompressed_size,
+                    .compressed_size = local_header.compressed_size,
+                    .local_file_header_offset = 0,
+                };
+                if (local_header.extra_len > 0) {
+                    var extra_buf: [std.math.maxInt(u16)]u8 = undefined;
+                    const extra = extra_buf[0..local_header.extra_len];
+
+                    {
+                        try stream.seekTo(self.file_offset + @sizeOf(LocalFileHeader) + local_header.filename_len);
+                        try stream.interface.readSliceAll(extra);
+                    }
+
+                    var extra_offset: usize = 0;
+                    while (extra_offset + 4 <= local_header.extra_len) {
+                        const header_id = std.mem.readInt(u16, extra[extra_offset..][0..2], .little);
+                        const data_size = std.mem.readInt(u16, extra[extra_offset..][2..4], .little);
+                        const end = extra_offset + 4 + data_size;
+                        if (end > local_header.extra_len)
+                            return error.ZipBadExtraFieldSize;
+                        const data = extra[extra_offset + 4 .. end];
+                        switch (@as(ExtraHeader, @enumFromInt(header_id))) {
+                            .zip64_info => try readZip64FileExtents(LocalFileHeader, local_header, &extents, data),
+                            else => {}, // ignore
+                        }
+                        extra_offset = end;
+                    }
+                }
+
+                if (extents.compressed_size != 0 and
+                    extents.compressed_size != self.compressed_size)
+                    return error.ZipMismatchCompLen;
+                if (extents.uncompressed_size != 0 and
+                    extents.uncompressed_size != self.uncompressed_size)
+                    return error.ZipMismatchUncompLen;
+
+                if (local_header.filename_len != self.filename_len)
+                    return error.ZipMismatchFilenameLen;
+
+                break :local_data_header_offset @as(u64, local_header.filename_len) +
+                    @as(u64, local_header.extra_len);
+            };
+
+            if (isBadFilename(filename))
+                return error.ZipBadFilename;
+
+            if (options.allow_backslashes) {
+                std.mem.replaceScalar(u8, filename, '\\', '/');
+            } else {
+                if (std.mem.indexOfScalar(u8, filename, '\\')) |_|
+                    return error.ZipFilenameHasBackslash;
+            }
+
+            // All entries that end in '/' are directories
+            if (filename[filename.len - 1] == '/') {
+                if (self.uncompressed_size != 0)
+                    return error.ZipBadDirectorySize;
+                try dest.makePath(filename[0 .. filename.len - 1]);
+                return;
+            }
+
+            const out_file = blk: {
+                if (std.fs.path.dirname(filename)) |dirname| {
+                    var parent_dir = try dest.makeOpenPath(dirname, .{});
+                    defer parent_dir.close();
+
+                    const basename = std.fs.path.basename(filename);
+                    break :blk try parent_dir.createFile(basename, .{ .exclusive = true });
+                }
+                break :blk try dest.createFile(filename, .{ .exclusive = true });
+            };
+            defer out_file.close();
+            var out_file_buffer: [1024]u8 = undefined;
+            var file_writer = out_file.writer(&out_file_buffer);
+            const local_data_file_offset: u64 =
+                @as(u64, self.file_offset) +
+                @as(u64, @sizeOf(LocalFileHeader)) +
+                local_data_header_offset;
+            try stream.seekTo(local_data_file_offset);
+
+            // TODO limit based on self.compressed_size
+
+            switch (self.compression_method) {
+                .store => {
+                    stream.interface.streamExact64(&file_writer.interface, self.uncompressed_size) catch |err| switch (err) {
+                        error.ReadFailed => return stream.err.?,
+                        error.WriteFailed => return file_writer.err.?,
+                        error.EndOfStream => return error.ZipDecompressTruncated,
+                    };
+                },
+                .deflate => {
+                    var flate_buffer: [flate.max_window_len]u8 = undefined;
+                    var decompress: flate.Decompress = .init(&stream.interface, .raw, &flate_buffer);
+                    decompress.reader.streamExact64(&file_writer.interface, self.uncompressed_size) catch |err| switch (err) {
+                        error.ReadFailed => return stream.err.?,
+                        error.WriteFailed => return file_writer.err orelse decompress.err.?,
+                        error.EndOfStream => return error.ZipDecompressTruncated,
+                    };
+                },
+                else => return error.UnsupportedCompressionMethod,
+            }
+            try file_writer.end();
+        }
     };
-}
+};
 
 // returns true if `filename` starts with `root` followed by a forward slash
 fn filenameInRoot(filename: []const u8, root: []const u8) bool {
@@ -610,196 +642,21 @@ pub const ExtractOptions = struct {
     /// Allow filenames within the zip to use backslashes.  Back slashes are normalized
     /// to forward slashes before forwarding them to platform APIs.
     allow_backslashes: bool = false,
-
     diagnostics: ?*Diagnostics = null,
+    verify_checksums: bool = false,
 };
 
-/// Extract the zipped files inside `seekable_stream` to the given `dest` directory.
-/// Note that `seekable_stream` must be an instance of `std.io.SeekableStream` and
-/// its context must also have a `.reader()` method that returns an instance of
-/// `std.io.GenericReader`.
-pub fn extract(dest: std.fs.Dir, seekable_stream: anytype, options: ExtractOptions) !void {
-    const SeekableStream = @TypeOf(seekable_stream);
-    var iter = try Iterator(SeekableStream).init(seekable_stream);
+/// Extract the zipped files to the given `dest` directory.
+pub fn extract(dest: std.fs.Dir, fr: *File.Reader, options: ExtractOptions) !void {
+    if (options.verify_checksums) @panic("TODO unimplemented");
+
+    var iter = try Iterator.init(fr);
 
     var filename_buf: [std.fs.max_path_bytes]u8 = undefined;
     while (try iter.next()) |entry| {
-        const crc32 = try entry.extract(seekable_stream, options, &filename_buf, dest);
-        if (crc32 != entry.crc32)
-            return error.ZipCrcMismatch;
+        try entry.extract(fr, options, &filename_buf, dest);
         if (options.diagnostics) |d| {
             try d.nextFilename(filename_buf[0..entry.filename_len]);
         }
     }
 }
-
-fn testZip(options: ExtractOptions, comptime files: []const File, write_opt: testutil.WriteZipOptions) !void {
-    var store: [files.len]FileStore = undefined;
-    try testZipWithStore(options, files, write_opt, &store);
-}
-fn testZipWithStore(
-    options: ExtractOptions,
-    test_files: []const File,
-    write_opt: testutil.WriteZipOptions,
-    store: []FileStore,
-) !void {
-    var zip_buf: [4096]u8 = undefined;
-    var fbs = try testutil.makeZipWithStore(&zip_buf, test_files, write_opt, store);
-
-    var tmp = testing.tmpDir(.{ .no_follow = true });
-    defer tmp.cleanup();
-    try extract(tmp.dir, fbs.seekableStream(), options);
-    try testutil.expectFiles(test_files, tmp.dir, .{});
-}
-fn testZipError(expected_error: anyerror, file: File, options: ExtractOptions) !void {
-    var zip_buf: [4096]u8 = undefined;
-    var store: [1]FileStore = undefined;
-    var fbs = try testutil.makeZipWithStore(&zip_buf, &[_]File{file}, .{}, &store);
-    var tmp = testing.tmpDir(.{ .no_follow = true });
-    defer tmp.cleanup();
-    try testing.expectError(expected_error, extract(tmp.dir, fbs.seekableStream(), options));
-}
-
-test "zip one file" {
-    try testZip(.{}, &[_]File{
-        .{ .name = "onefile.txt", .content = "Just a single file\n", .compression = .store },
-    }, .{});
-}
-test "zip multiple files" {
-    try testZip(.{ .allow_backslashes = true }, &[_]File{
-        .{ .name = "foo", .content = "a foo file\n", .compression = .store },
-        .{ .name = "subdir/bar", .content = "bar is this right?\nanother newline\n", .compression = .store },
-        .{ .name = "subdir\\whoa", .content = "you can do backslashes", .compression = .store },
-        .{ .name = "subdir/another/baz", .content = "bazzy mc bazzerson", .compression = .store },
-    }, .{});
-}
-test "zip deflated" {
-    try testZip(.{}, &[_]File{
-        .{ .name = "deflateme", .content = "This is a deflated file.\nIt should be smaller in the Zip file1\n", .compression = .deflate },
-        // TODO: re-enable this if/when we add support for deflate64
-        //.{ .name = "deflateme64", .content = "The 64k version of deflate!\n", .compression = .deflate64 },
-        .{ .name = "raw", .content = "Not all files need to be deflated in the same Zip.\n", .compression = .store },
-    }, .{});
-}
-test "zip verify filenames" {
-    // no empty filenames
-    try testZipError(error.ZipBadFilename, .{ .name = "", .content = "", .compression = .store }, .{});
-    // no absolute paths
-    try testZipError(error.ZipBadFilename, .{ .name = "/", .content = "", .compression = .store }, .{});
-    try testZipError(error.ZipBadFilename, .{ .name = "/foo", .content = "", .compression = .store }, .{});
-    try testZipError(error.ZipBadFilename, .{ .name = "/foo/bar", .content = "", .compression = .store }, .{});
-    // no '..' components
-    try testZipError(error.ZipBadFilename, .{ .name = "..", .content = "", .compression = .store }, .{});
-    try testZipError(error.ZipBadFilename, .{ .name = "foo/..", .content = "", .compression = .store }, .{});
-    try testZipError(error.ZipBadFilename, .{ .name = "foo/bar/..", .content = "", .compression = .store }, .{});
-    try testZipError(error.ZipBadFilename, .{ .name = "foo/bar/../", .content = "", .compression = .store }, .{});
-    // no backslashes
-    try testZipError(error.ZipFilenameHasBackslash, .{ .name = "foo\\bar", .content = "", .compression = .store }, .{});
-}
-
-test "zip64" {
-    const test_files = [_]File{
-        .{ .name = "fram", .content = "fram foo fro fraba", .compression = .store },
-        .{ .name = "subdir/barro", .content = "aljdk;jal;jfd;lajkf", .compression = .store },
-    };
-
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .record_count_disk = std.math.maxInt(u16), // trigger zip64
-        },
-    });
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .record_count_total = std.math.maxInt(u16), // trigger zip64
-        },
-    });
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .record_count_disk = std.math.maxInt(u16), // trigger zip64
-            .record_count_total = std.math.maxInt(u16), // trigger zip64
-        },
-    });
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .central_directory_size = std.math.maxInt(u32), // trigger zip64
-        },
-    });
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .central_directory_offset = std.math.maxInt(u32), // trigger zip64
-        },
-    });
-    try testZip(.{}, &test_files, .{
-        .end = .{
-            .zip64 = .{},
-            .central_directory_offset = std.math.maxInt(u32), // trigger zip64
-        },
-        .local_header = .{
-            .zip64 = .{ // trigger local header zip64
-                .data_size = 16,
-            },
-            .compressed_size = std.math.maxInt(u32),
-            .uncompressed_size = std.math.maxInt(u32),
-            .extra_len = 20,
-        },
-    });
-}
-
-test "bad zip files" {
-    var tmp = testing.tmpDir(.{ .no_follow = true });
-    defer tmp.cleanup();
-    var zip_buf: [4096]u8 = undefined;
-
-    const file_a = [_]File{.{ .name = "a", .content = "", .compression = .store }};
-
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .sig = [_]u8{ 1, 2, 3, 4 } } });
-        try testing.expectError(error.ZipNoEndRecord, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .comment_len = 1 } });
-        try testing.expectError(error.ZipNoEndRecord, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .comment = "a", .comment_len = 0 } });
-        try testing.expectError(error.ZipNoEndRecord, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .disk_number = 1 } });
-        try testing.expectError(error.ZipMultiDiskUnsupported, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .central_directory_disk_number = 1 } });
-        try testing.expectError(error.ZipMultiDiskUnsupported, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .record_count_disk = 1 } });
-        try testing.expectError(error.ZipDiskRecordCountTooLarge, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &.{}, .{ .end = .{ .central_directory_size = 1 } });
-        try testing.expectError(error.ZipCdOversized, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &file_a, .{ .end = .{ .central_directory_size = 0 } });
-        try testing.expectError(error.ZipCdUndersized, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &file_a, .{ .end = .{ .central_directory_offset = 0 } });
-        try testing.expectError(error.ZipBadCdOffset, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-    {
-        var fbs = try testutil.makeZip(&zip_buf, &file_a, .{
-            .end = .{
-                .zip64 = .{ .locator_sig = [_]u8{ 1, 2, 3, 4 } },
-                .central_directory_size = std.math.maxInt(u32), // trigger 64
-            },
-        });
-        try testing.expectError(error.ZipBadLocatorSig, extract(tmp.dir, fbs.seekableStream(), .{}));
-    }
-}
diff --git a/lib/std/zip/test.zig b/lib/std/zip/test.zig
deleted file mode 100644
index 27f12cf2a6..0000000000
--- a/lib/std/zip/test.zig
+++ /dev/null
@@ -1,298 +0,0 @@
-const std = @import("std");
-const testing = std.testing;
-const zip = @import("../zip.zig");
-const maxInt = std.math.maxInt;
-
-pub const File = struct {
-    name: []const u8,
-    content: []const u8,
-    compression: zip.CompressionMethod,
-};
-
-pub fn expectFiles(
-    test_files: []const File,
-    dir: std.fs.Dir,
-    opt: struct {
-        strip_prefix: ?[]const u8 = null,
-    },
-) !void {
-    for (test_files) |test_file| {
-        var normalized_sub_path_buf: [std.fs.max_path_bytes]u8 = undefined;
-
-        const name = blk: {
-            if (opt.strip_prefix) |strip_prefix| {
-                try testing.expect(test_file.name.len >= strip_prefix.len);
-                try testing.expectEqualStrings(strip_prefix, test_file.name[0..strip_prefix.len]);
-                break :blk test_file.name[strip_prefix.len..];
-            }
-            break :blk test_file.name;
-        };
-        const normalized_sub_path = normalized_sub_path_buf[0..name.len];
-        @memcpy(normalized_sub_path, name);
-        std.mem.replaceScalar(u8, normalized_sub_path, '\\', '/');
-        var file = try dir.openFile(normalized_sub_path, .{});
-        defer file.close();
-        var content_buf: [4096]u8 = undefined;
-        const n = try file.deprecatedReader().readAll(&content_buf);
-        try testing.expectEqualStrings(test_file.content, content_buf[0..n]);
-    }
-}
-
-// Used to store any data from writing a file to the zip archive that's needed
-// when writing the corresponding central directory record.
-pub const FileStore = struct {
-    compression: zip.CompressionMethod,
-    file_offset: u64,
-    crc32: u32,
-    compressed_size: u32,
-    uncompressed_size: usize,
-};
-
-pub fn makeZip(
-    buf: []u8,
-    comptime files: []const File,
-    options: WriteZipOptions,
-) !std.io.FixedBufferStream([]u8) {
-    var store: [files.len]FileStore = undefined;
-    return try makeZipWithStore(buf, files, options, &store);
-}
-
-pub fn makeZipWithStore(
-    buf: []u8,
-    files: []const File,
-    options: WriteZipOptions,
-    store: []FileStore,
-) !std.io.FixedBufferStream([]u8) {
-    var fbs = std.io.fixedBufferStream(buf);
-    try writeZip(fbs.writer(), files, store, options);
-    return std.io.fixedBufferStream(buf[0..fbs.pos]);
-}
-
-pub const WriteZipOptions = struct {
-    end: ?EndRecordOptions = null,
-    local_header: ?LocalHeaderOptions = null,
-};
-pub const LocalHeaderOptions = struct {
-    zip64: ?LocalHeaderZip64Options = null,
-    compressed_size: ?u32 = null,
-    uncompressed_size: ?u32 = null,
-    extra_len: ?u16 = null,
-};
-pub const LocalHeaderZip64Options = struct {
-    data_size: ?u16 = null,
-};
-pub const EndRecordOptions = struct {
-    zip64: ?Zip64Options = null,
-    sig: ?[4]u8 = null,
-    disk_number: ?u16 = null,
-    central_directory_disk_number: ?u16 = null,
-    record_count_disk: ?u16 = null,
-    record_count_total: ?u16 = null,
-    central_directory_size: ?u32 = null,
-    central_directory_offset: ?u32 = null,
-    comment_len: ?u16 = null,
-    comment: ?[]const u8 = null,
-};
-pub const Zip64Options = struct {
-    locator_sig: ?[4]u8 = null,
-    locator_zip64_disk_count: ?u32 = null,
-    locator_record_file_offset: ?u64 = null,
-    locator_total_disk_count: ?u32 = null,
-    //record_size: ?u64 = null,
-    central_directory_size: ?u64 = null,
-};
-
-pub fn writeZip(
-    writer: anytype,
-    files: []const File,
-    store: []FileStore,
-    options: WriteZipOptions,
-) !void {
-    if (store.len < files.len) return error.FileStoreTooSmall;
-    var zipper = initZipper(writer);
-    for (files, 0..) |file, i| {
-        store[i] = try zipper.writeFile(.{
-            .name = file.name,
-            .content = file.content,
-            .compression = file.compression,
-            .write_options = options,
-        });
-    }
-    for (files, 0..) |file, i| {
-        try zipper.writeCentralRecord(store[i], .{
-            .name = file.name,
-        });
-    }
-    try zipper.writeEndRecord(if (options.end) |e| e else .{});
-}
-
-pub fn initZipper(writer: anytype) Zipper(@TypeOf(writer)) {
-    return .{ .counting_writer = std.io.countingWriter(writer) };
-}
-
-/// Provides methods to format and write the contents of a zip archive
-/// to the underlying Writer.
-pub fn Zipper(comptime Writer: type) type {
-    return struct {
-        counting_writer: std.io.CountingWriter(Writer),
-        central_count: u64 = 0,
-        first_central_offset: ?u64 = null,
-        last_central_limit: ?u64 = null,
-
-        const Self = @This();
-
-        pub fn writeFile(
-            self: *Self,
-            opt: struct {
-                name: []const u8,
-                content: []const u8,
-                compression: zip.CompressionMethod,
-                write_options: WriteZipOptions,
-            },
-        ) !FileStore {
-            const writer = self.counting_writer.writer();
-
-            const file_offset: u64 = @intCast(self.counting_writer.bytes_written);
-            const crc32 = std.hash.Crc32.hash(opt.content);
-
-            const header_options = opt.write_options.local_header;
-            {
-                var compressed_size: u32 = 0;
-                var uncompressed_size: u32 = 0;
-                var extra_len: u16 = 0;
-                if (header_options) |hdr_options| {
-                    compressed_size = if (hdr_options.compressed_size) |size| size else 0;
-                    uncompressed_size = if (hdr_options.uncompressed_size) |size| size else @intCast(opt.content.len);
-                    extra_len = if (hdr_options.extra_len) |len| len else 0;
-                }
-                const hdr: zip.LocalFileHeader = .{
-                    .signature = zip.local_file_header_sig,
-                    .version_needed_to_extract = 10,
-                    .flags = .{ .encrypted = false, ._ = 0 },
-                    .compression_method = opt.compression,
-                    .last_modification_time = 0,
-                    .last_modification_date = 0,
-                    .crc32 = crc32,
-                    .compressed_size = compressed_size,
-                    .uncompressed_size = uncompressed_size,
-                    .filename_len = @intCast(opt.name.len),
-                    .extra_len = extra_len,
-                };
-                try writer.writeStructEndian(hdr, .little);
-            }
-            try writer.writeAll(opt.name);
-
-            if (header_options) |hdr| {
-                if (hdr.zip64) |options| {
-                    try writer.writeInt(u16, 0x0001, .little);
-                    const data_size = if (options.data_size) |size| size else 8;
-                    try writer.writeInt(u16, data_size, .little);
-                    try writer.writeInt(u64, 0, .little);
-                    try writer.writeInt(u64, @intCast(opt.content.len), .little);
-                }
-            }
-
-            var compressed_size: u32 = undefined;
-            switch (opt.compression) {
-                .store => {
-                    try writer.writeAll(opt.content);
-                    compressed_size = @intCast(opt.content.len);
-                },
-                .deflate => {
-                    const offset = self.counting_writer.bytes_written;
-                    var fbs = std.io.fixedBufferStream(opt.content);
-                    try std.compress.flate.deflate.compress(.raw, fbs.reader(), writer, .{});
-                    std.debug.assert(fbs.pos == opt.content.len);
-                    compressed_size = @intCast(self.counting_writer.bytes_written - offset);
-                },
-                else => unreachable,
-            }
-            return .{
-                .compression = opt.compression,
-                .file_offset = file_offset,
-                .crc32 = crc32,
-                .compressed_size = compressed_size,
-                .uncompressed_size = opt.content.len,
-            };
-        }
-
-        pub fn writeCentralRecord(
-            self: *Self,
-            store: FileStore,
-            opt: struct {
-                name: []const u8,
-                version_needed_to_extract: u16 = 10,
-            },
-        ) !void {
-            if (self.first_central_offset == null) {
-                self.first_central_offset = self.counting_writer.bytes_written;
-            }
-            self.central_count += 1;
-
-            const hdr: zip.CentralDirectoryFileHeader = .{
-                .signature = zip.central_file_header_sig,
-                .version_made_by = 0,
-                .version_needed_to_extract = opt.version_needed_to_extract,
-                .flags = .{ .encrypted = false, ._ = 0 },
-                .compression_method = store.compression,
-                .last_modification_time = 0,
-                .last_modification_date = 0,
-                .crc32 = store.crc32,
-                .compressed_size = store.compressed_size,
-                .uncompressed_size = @intCast(store.uncompressed_size),
-                .filename_len = @intCast(opt.name.len),
-                .extra_len = 0,
-                .comment_len = 0,
-                .disk_number = 0,
-                .internal_file_attributes = 0,
-                .external_file_attributes = 0,
-                .local_file_header_offset = @intCast(store.file_offset),
-            };
-            try self.counting_writer.writer().writeStructEndian(hdr, .little);
-            try self.counting_writer.writer().writeAll(opt.name);
-            self.last_central_limit = self.counting_writer.bytes_written;
-        }
-
-        pub fn writeEndRecord(self: *Self, opt: EndRecordOptions) !void {
-            const cd_offset = self.first_central_offset orelse 0;
-            const cd_end = self.last_central_limit orelse 0;
-
-            if (opt.zip64) |zip64| {
-                const end64_off = cd_end;
-                const fixed: zip.EndRecord64 = .{
-                    .signature = zip.end_record64_sig,
-                    .end_record_size = @sizeOf(zip.EndRecord64) - 12,
-                    .version_made_by = 0,
-                    .version_needed_to_extract = 45,
-                    .disk_number = 0,
-                    .central_directory_disk_number = 0,
-                    .record_count_disk = @intCast(self.central_count),
-                    .record_count_total = @intCast(self.central_count),
-                    .central_directory_size = @intCast(cd_end - cd_offset),
-                    .central_directory_offset = @intCast(cd_offset),
-                };
-                try self.counting_writer.writer().writeStructEndian(fixed, .little);
-                const locator: zip.EndLocator64 = .{
-                    .signature = if (zip64.locator_sig) |s| s else zip.end_locator64_sig,
-                    .zip64_disk_count = if (zip64.locator_zip64_disk_count) |c| c else 0,
-                    .record_file_offset = if (zip64.locator_record_file_offset) |o| o else @intCast(end64_off),
-                    .total_disk_count = if (zip64.locator_total_disk_count) |c| c else 1,
-                };
-                try self.counting_writer.writer().writeStructEndian(locator, .little);
-            }
-            const hdr: zip.EndRecord = .{
-                .signature = if (opt.sig) |s| s else zip.end_record_sig,
-                .disk_number = if (opt.disk_number) |n| n else 0,
-                .central_directory_disk_number = if (opt.central_directory_disk_number) |n| n else 0,
-                .record_count_disk = if (opt.record_count_disk) |c| c else @intCast(self.central_count),
-                .record_count_total = if (opt.record_count_total) |c| c else @intCast(self.central_count),
-                .central_directory_size = if (opt.central_directory_size) |s| s else @intCast(cd_end - cd_offset),
-                .central_directory_offset = if (opt.central_directory_offset) |o| o else @intCast(cd_offset),
-                .comment_len = if (opt.comment_len) |l| l else (if (opt.comment) |c| @as(u16, @intCast(c.len)) else 0),
-            };
-            try self.counting_writer.writer().writeStructEndian(hdr, .little);
-            if (opt.comment) |c|
-                try self.counting_writer.writer().writeAll(c);
-        }
-    };
-}
diff --git a/src/Package/Fetch.zig b/src/Package/Fetch.zig
index f47086bf58..836435a86b 100644
--- a/src/Package/Fetch.zig
+++ b/src/Package/Fetch.zig
@@ -1203,12 +1203,11 @@ fn unpackResource(
             return unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
         },
         .@"tar.gz" => {
-            const reader = resource.reader();
-            var br = std.io.bufferedReaderSize(std.crypto.tls.max_ciphertext_record_len, reader);
-            var dcp = std.compress.gzip.decompressor(br.reader());
-            var adapter_buffer: [1024]u8 = undefined;
-            var adapter = dcp.reader().adaptToNewApi(&adapter_buffer);
-            return try unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
+            var adapter_buffer: [std.crypto.tls.max_ciphertext_record_len]u8 = undefined;
+            var adapter = resource.reader().adaptToNewApi(&adapter_buffer);
+            var flate_buffer: [std.compress.flate.max_window_len]u8 = undefined;
+            var decompress: std.compress.flate.Decompress = .init(&adapter.new_interface, .gzip, &flate_buffer);
+            return try unpackTarball(f, tmp_directory.handle, &decompress.reader);
         },
         .@"tar.xz" => {
             const gpa = f.arena.child_allocator;
@@ -1352,7 +1351,10 @@ fn unzip(f: *Fetch, out_dir: fs.Dir, reader: anytype) RunError!UnpackResult {
         ));
         defer zip_file.close();
 
-        std.zip.extract(out_dir, zip_file.seekableStream(), .{
+        var zip_file_buffer: [1024]u8 = undefined;
+        var zip_file_reader = zip_file.reader(&zip_file_buffer);
+
+        std.zip.extract(out_dir, &zip_file_reader, .{
             .allow_backslashes = true,
             .diagnostics = &diagnostics,
         }) catch |err| return f.fail(f.location_tok, try eb.printString(
@@ -1384,23 +1386,28 @@ fn unpackGitPack(f: *Fetch, out_dir: fs.Dir, resource: *Resource.Git) anyerror!U
         defer pack_dir.close();
         var pack_file = try pack_dir.createFile("pkg.pack", .{ .read = true });
         defer pack_file.close();
-        var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
+        var pack_file_buffer: [4096]u8 = undefined;
+        var fifo = std.fifo.LinearFifo(u8, .{ .Slice = {} }).init(&pack_file_buffer);
         try fifo.pump(resource.fetch_stream.reader(), pack_file.deprecatedWriter());
 
+        var pack_file_reader = pack_file.reader(&pack_file_buffer);
+
         var index_file = try pack_dir.createFile("pkg.idx", .{ .read = true });
         defer index_file.close();
+        var index_file_buffer: [2000]u8 = undefined;
+        var index_file_writer = index_file.writer(&index_file_buffer);
         {
             const index_prog_node = f.prog_node.start("Index pack", 0);
             defer index_prog_node.end();
-            var index_buffered_writer = std.io.bufferedWriter(index_file.deprecatedWriter());
-            try git.indexPack(gpa, object_format, pack_file, index_buffered_writer.writer());
-            try index_buffered_writer.flush();
+            try git.indexPack(gpa, object_format, &pack_file_reader, &index_file_writer);
         }
 
         {
+            var index_file_reader = index_file.reader(&index_file_buffer);
             const checkout_prog_node = f.prog_node.start("Checkout", 0);
             defer checkout_prog_node.end();
-            var repository = try git.Repository.init(gpa, object_format, pack_file, index_file);
+            var repository: git.Repository = undefined;
+            try repository.init(gpa, object_format, &pack_file_reader, &index_file_reader);
             defer repository.deinit();
             var diagnostics: git.Diagnostics = .{ .allocator = arena };
             try repository.checkout(out_dir, resource.want_oid, &diagnostics);
@@ -2071,72 +2078,6 @@ const UnpackResult = struct {
     }
 };
 
-test "zip" {
-    const gpa = std.testing.allocator;
-    var tmp = std.testing.tmpDir(.{});
-    defer tmp.cleanup();
-
-    const test_files = [_]std.zip.testutil.File{
-        .{ .name = "foo", .content = "this is just foo\n", .compression = .store },
-        .{ .name = "bar", .content = "another file\n", .compression = .deflate },
-    };
-    {
-        var zip_file = try tmp.dir.createFile("test.zip", .{});
-        defer zip_file.close();
-        var bw = std.io.bufferedWriter(zip_file.deprecatedWriter());
-        var store: [test_files.len]std.zip.testutil.FileStore = undefined;
-        try std.zip.testutil.writeZip(bw.writer(), &test_files, &store, .{});
-        try bw.flush();
-    }
-
-    const zip_path = try std.fmt.allocPrint(gpa, ".zig-cache/tmp/{s}/test.zip", .{tmp.sub_path});
-    defer gpa.free(zip_path);
-
-    var fb: TestFetchBuilder = undefined;
-    var fetch = try fb.build(gpa, tmp.dir, zip_path);
-    defer fb.deinit();
-
-    try fetch.run();
-
-    var out = try fb.packageDir();
-    defer out.close();
-
-    try std.zip.testutil.expectFiles(&test_files, out, .{});
-}
-
-test "zip with one root folder" {
-    const gpa = std.testing.allocator;
-    var tmp = std.testing.tmpDir(.{});
-    defer tmp.cleanup();
-
-    const test_files = [_]std.zip.testutil.File{
-        .{ .name = "the_root_folder/foo.zig", .content = "// this is foo.zig\n", .compression = .store },
-        .{ .name = "the_root_folder/README.md", .content = "# The foo.zig README\n", .compression = .store },
-    };
-    {
-        var zip_file = try tmp.dir.createFile("test.zip", .{});
-        defer zip_file.close();
-        var bw = std.io.bufferedWriter(zip_file.deprecatedWriter());
-        var store: [test_files.len]std.zip.testutil.FileStore = undefined;
-        try std.zip.testutil.writeZip(bw.writer(), &test_files, &store, .{});
-        try bw.flush();
-    }
-
-    const zip_path = try std.fmt.allocPrint(gpa, ".zig-cache/tmp/{s}/test.zip", .{tmp.sub_path});
-    defer gpa.free(zip_path);
-
-    var fb: TestFetchBuilder = undefined;
-    var fetch = try fb.build(gpa, tmp.dir, zip_path);
-    defer fb.deinit();
-
-    try fetch.run();
-
-    var out = try fb.packageDir();
-    defer out.close();
-
-    try std.zip.testutil.expectFiles(&test_files, out, .{ .strip_prefix = "the_root_folder/" });
-}
-
 test "tarball with duplicate paths" {
     // This tarball has duplicate path 'dir1/file1' to simulate case sensitve
     // file system on any file sytstem.
diff --git a/src/Package/Fetch/git.zig b/src/Package/Fetch/git.zig
index 34d373f553..8f5bff2522 100644
--- a/src/Package/Fetch/git.zig
+++ b/src/Package/Fetch/git.zig
@@ -66,6 +66,33 @@ pub const Oid = union(Format) {
         }
     };
 
+    const Hashing = union(Format) {
+        sha1: std.Io.Writer.Hashing(Sha1),
+        sha256: std.Io.Writer.Hashing(Sha256),
+
+        fn init(oid_format: Format, buffer: []u8) Hashing {
+            return switch (oid_format) {
+                .sha1 => .{ .sha1 = .init(buffer) },
+                .sha256 => .{ .sha256 = .init(buffer) },
+            };
+        }
+
+        fn writer(h: *@This()) *std.Io.Writer {
+            return switch (h.*) {
+                inline else => |*inner| &inner.writer,
+            };
+        }
+
+        fn final(h: *@This()) Oid {
+            switch (h.*) {
+                inline else => |*inner, tag| {
+                    inner.writer.flush() catch unreachable; // hashers cannot fail
+                    return @unionInit(Oid, @tagName(tag), inner.hasher.finalResult());
+                },
+            }
+        }
+    };
+
     pub fn fromBytes(oid_format: Format, bytes: []const u8) Oid {
         assert(bytes.len == oid_format.byteLength());
         return switch (oid_format) {
@@ -73,9 +100,9 @@ pub const Oid = union(Format) {
         };
     }
 
-    pub fn readBytes(oid_format: Format, reader: anytype) @TypeOf(reader).NoEofError!Oid {
+    pub fn readBytes(oid_format: Format, reader: *std.Io.Reader) !Oid {
         return switch (oid_format) {
-            inline else => |tag| @unionInit(Oid, @tagName(tag), try reader.readBytesNoEof(tag.byteLength())),
+            inline else => |tag| @unionInit(Oid, @tagName(tag), (try reader.takeArray(tag.byteLength())).*),
         };
     }
 
@@ -166,8 +193,15 @@ pub const Diagnostics = struct {
 pub const Repository = struct {
     odb: Odb,
 
-    pub fn init(allocator: Allocator, format: Oid.Format, pack_file: std.fs.File, index_file: std.fs.File) !Repository {
-        return .{ .odb = try Odb.init(allocator, format, pack_file, index_file) };
+    pub fn init(
+        repo: *Repository,
+        allocator: Allocator,
+        format: Oid.Format,
+        pack_file: *std.fs.File.Reader,
+        index_file: *std.fs.File.Reader,
+    ) !void {
+        repo.* = .{ .odb = undefined };
+        try repo.odb.init(allocator, format, pack_file, index_file);
     }
 
     pub fn deinit(repository: *Repository) void {
@@ -335,24 +369,30 @@ pub const Repository = struct {
 /// [pack-format](https://git-scm.com/docs/pack-format).
 const Odb = struct {
     format: Oid.Format,
-    pack_file: std.fs.File,
+    pack_file: *std.fs.File.Reader,
     index_header: IndexHeader,
-    index_file: std.fs.File,
+    index_file: *std.fs.File.Reader,
     cache: ObjectCache = .{},
     allocator: Allocator,
 
     /// Initializes the database from open pack and index files.
-    fn init(allocator: Allocator, format: Oid.Format, pack_file: std.fs.File, index_file: std.fs.File) !Odb {
+    fn init(
+        odb: *Odb,
+        allocator: Allocator,
+        format: Oid.Format,
+        pack_file: *std.fs.File.Reader,
+        index_file: *std.fs.File.Reader,
+    ) !void {
         try pack_file.seekTo(0);
         try index_file.seekTo(0);
-        const index_header = try IndexHeader.read(index_file.deprecatedReader());
-        return .{
+        odb.* = .{
             .format = format,
             .pack_file = pack_file,
-            .index_header = index_header,
+            .index_header = undefined,
             .index_file = index_file,
             .allocator = allocator,
         };
+        try odb.index_header.read(&index_file.interface);
     }
 
     fn deinit(odb: *Odb) void {
@@ -362,14 +402,14 @@ const Odb = struct {
 
     /// Reads the object at the current position in the database.
     fn readObject(odb: *Odb) !Object {
-        var base_offset = try odb.pack_file.getPos();
+        var base_offset = odb.pack_file.logicalPos();
         var base_header: EntryHeader = undefined;
         var delta_offsets: std.ArrayListUnmanaged(u64) = .empty;
         defer delta_offsets.deinit(odb.allocator);
         const base_object = while (true) {
             if (odb.cache.get(base_offset)) |base_object| break base_object;
 
-            base_header = try EntryHeader.read(odb.format, odb.pack_file.deprecatedReader());
+            base_header = try EntryHeader.read(odb.format, &odb.pack_file.interface);
             switch (base_header) {
                 .ofs_delta => |ofs_delta| {
                     try delta_offsets.append(odb.allocator, base_offset);
@@ -379,10 +419,10 @@ const Odb = struct {
                 .ref_delta => |ref_delta| {
                     try delta_offsets.append(odb.allocator, base_offset);
                     try odb.seekOid(ref_delta.base_object);
-                    base_offset = try odb.pack_file.getPos();
+                    base_offset = odb.pack_file.logicalPos();
                 },
                 else => {
-                    const base_data = try readObjectRaw(odb.allocator, odb.pack_file.deprecatedReader(), base_header.uncompressedLength());
+                    const base_data = try readObjectRaw(odb.allocator, &odb.pack_file.interface, base_header.uncompressedLength());
                     errdefer odb.allocator.free(base_data);
                     const base_object: Object = .{ .type = base_header.objectType(), .data = base_data };
                     try odb.cache.put(odb.allocator, base_offset, base_object);
@@ -412,7 +452,7 @@ const Odb = struct {
         const found_index = while (start_index < end_index) {
             const mid_index = start_index + (end_index - start_index) / 2;
             try odb.index_file.seekTo(IndexHeader.size + mid_index * oid_length);
-            const mid_oid = try Oid.readBytes(odb.format, odb.index_file.deprecatedReader());
+            const mid_oid = try Oid.readBytes(odb.format, &odb.index_file.interface);
             switch (mem.order(u8, mid_oid.slice(), oid.slice())) {
                 .lt => start_index = mid_index + 1,
                 .gt => end_index = mid_index,
@@ -423,12 +463,12 @@ const Odb = struct {
         const n_objects = odb.index_header.fan_out_table[255];
         const offset_values_start = IndexHeader.size + n_objects * (oid_length + 4);
         try odb.index_file.seekTo(offset_values_start + found_index * 4);
-        const l1_offset: packed struct { value: u31, big: bool } = @bitCast(try odb.index_file.deprecatedReader().readInt(u32, .big));
+        const l1_offset: packed struct { value: u31, big: bool } = @bitCast(try odb.index_file.interface.takeInt(u32, .big));
         const pack_offset = pack_offset: {
             if (l1_offset.big) {
                 const l2_offset_values_start = offset_values_start + n_objects * 4;
                 try odb.index_file.seekTo(l2_offset_values_start + l1_offset.value * 4);
-                break :pack_offset try odb.index_file.deprecatedReader().readInt(u64, .big);
+                break :pack_offset try odb.index_file.interface.takeInt(u64, .big);
             } else {
                 break :pack_offset l1_offset.value;
             }
@@ -1080,18 +1120,18 @@ const PackHeader = struct {
     const signature = "PACK";
     const supported_version = 2;
 
-    fn read(reader: anytype) !PackHeader {
-        const actual_signature = reader.readBytesNoEof(4) catch |e| switch (e) {
+    fn read(reader: *std.Io.Reader) !PackHeader {
+        const actual_signature = reader.take(4) catch |e| switch (e) {
             error.EndOfStream => return error.InvalidHeader,
             else => |other| return other,
         };
-        if (!mem.eql(u8, &actual_signature, signature)) return error.InvalidHeader;
-        const version = reader.readInt(u32, .big) catch |e| switch (e) {
+        if (!mem.eql(u8, actual_signature, signature)) return error.InvalidHeader;
+        const version = reader.takeInt(u32, .big) catch |e| switch (e) {
             error.EndOfStream => return error.InvalidHeader,
             else => |other| return other,
         };
         if (version != supported_version) return error.UnsupportedVersion;
-        const total_objects = reader.readInt(u32, .big) catch |e| switch (e) {
+        const total_objects = reader.takeInt(u32, .big) catch |e| switch (e) {
             error.EndOfStream => return error.InvalidHeader,
             else => |other| return other,
         };
@@ -1143,13 +1183,13 @@ const EntryHeader = union(Type) {
         };
     }
 
-    fn read(format: Oid.Format, reader: anytype) !EntryHeader {
+    fn read(format: Oid.Format, reader: *std.Io.Reader) !EntryHeader {
         const InitialByte = packed struct { len: u4, type: u3, has_next: bool };
-        const initial: InitialByte = @bitCast(reader.readByte() catch |e| switch (e) {
+        const initial: InitialByte = @bitCast(reader.takeByte() catch |e| switch (e) {
             error.EndOfStream => return error.InvalidFormat,
             else => |other| return other,
         });
-        const rest_len = if (initial.has_next) try readSizeVarInt(reader) else 0;
+        const rest_len = if (initial.has_next) try reader.takeLeb128(u64) else 0;
         var uncompressed_length: u64 = initial.len;
         uncompressed_length |= std.math.shlExact(u64, rest_len, 4) catch return error.InvalidFormat;
         const @"type" = std.enums.fromInt(EntryHeader.Type, initial.type) orelse return error.InvalidFormat;
@@ -1172,25 +1212,12 @@ const EntryHeader = union(Type) {
     }
 };
 
-fn readSizeVarInt(r: anytype) !u64 {
+fn readOffsetVarInt(r: *std.Io.Reader) !u64 {
     const Byte = packed struct { value: u7, has_next: bool };
-    var b: Byte = @bitCast(try r.readByte());
-    var value: u64 = b.value;
-    var shift: u6 = 0;
-    while (b.has_next) {
-        b = @bitCast(try r.readByte());
-        shift = std.math.add(u6, shift, 7) catch return error.InvalidFormat;
-        value |= @as(u64, b.value) << shift;
-    }
-    return value;
-}
-
-fn readOffsetVarInt(r: anytype) !u64 {
-    const Byte = packed struct { value: u7, has_next: bool };
-    var b: Byte = @bitCast(try r.readByte());
+    var b: Byte = @bitCast(try r.takeByte());
     var value: u64 = b.value;
     while (b.has_next) {
-        b = @bitCast(try r.readByte());
+        b = @bitCast(try r.takeByte());
         value = std.math.shlExact(u64, value + 1, 7) catch return error.InvalidFormat;
         value |= b.value;
     }
@@ -1204,19 +1231,12 @@ const IndexHeader = struct {
     const supported_version = 2;
     const size = 4 + 4 + @sizeOf([256]u32);
 
-    fn read(reader: anytype) !IndexHeader {
-        var header_bytes = try reader.readBytesNoEof(size);
-        if (!mem.eql(u8, header_bytes[0..4], signature)) return error.InvalidHeader;
-        const version = mem.readInt(u32, header_bytes[4..8], .big);
+    fn read(index_header: *IndexHeader, reader: *std.Io.Reader) !void {
+        const sig = try reader.take(4);
+        if (!mem.eql(u8, sig, signature)) return error.InvalidHeader;
+        const version = try reader.takeInt(u32, .big);
         if (version != supported_version) return error.UnsupportedVersion;
-
-        var fan_out_table: [256]u32 = undefined;
-        var fan_out_table_stream = std.io.fixedBufferStream(header_bytes[8..]);
-        const fan_out_table_reader = fan_out_table_stream.reader();
-        for (&fan_out_table) |*entry| {
-            entry.* = fan_out_table_reader.readInt(u32, .big) catch unreachable;
-        }
-        return .{ .fan_out_table = fan_out_table };
+        try reader.readSliceEndian(u32, &index_header.fan_out_table, .big);
     }
 };
 
@@ -1227,7 +1247,12 @@ const IndexEntry = struct {
 
 /// Writes out a version 2 index for the given packfile, as documented in
 /// [pack-format](https://git-scm.com/docs/pack-format).
-pub fn indexPack(allocator: Allocator, format: Oid.Format, pack: std.fs.File, index_writer: anytype) !void {
+pub fn indexPack(
+    allocator: Allocator,
+    format: Oid.Format,
+    pack: *std.fs.File.Reader,
+    index_writer: *std.fs.File.Writer,
+) !void {
     try pack.seekTo(0);
 
     var index_entries: std.AutoHashMapUnmanaged(Oid, IndexEntry) = .empty;
@@ -1280,8 +1305,8 @@ pub fn indexPack(allocator: Allocator, format: Oid.Format, pack: std.fs.File, in
     }
     @memset(fan_out_table[fan_out_index..], count);
 
-    var index_hashed_writer = hashedWriter(index_writer, Oid.Hasher.init(format));
-    const writer = index_hashed_writer.writer();
+    var index_hashed_writer = std.Io.Writer.hashed(&index_writer.interface, Oid.Hasher.init(format), &.{});
+    const writer = &index_hashed_writer.writer;
     try writer.writeAll(IndexHeader.signature);
     try writer.writeInt(u32, IndexHeader.supported_version, .big);
     for (fan_out_table) |fan_out_entry| {
@@ -1314,7 +1339,8 @@ pub fn indexPack(allocator: Allocator, format: Oid.Format, pack: std.fs.File, in
 
     try writer.writeAll(pack_checksum.slice());
     const index_checksum = index_hashed_writer.hasher.finalResult();
-    try index_writer.writeAll(index_checksum.slice());
+    try index_writer.interface.writeAll(index_checksum.slice());
+    try index_writer.end();
 }
 
 /// Performs the first pass over the packfile data for index construction.
@@ -1324,68 +1350,51 @@ pub fn indexPack(allocator: Allocator, format: Oid.Format, pack: std.fs.File, in
 fn indexPackFirstPass(
     allocator: Allocator,
     format: Oid.Format,
-    pack: std.fs.File,
+    pack: *std.fs.File.Reader,
     index_entries: *std.AutoHashMapUnmanaged(Oid, IndexEntry),
     pending_deltas: *std.ArrayListUnmanaged(IndexEntry),
 ) !Oid {
-    var pack_buffered_reader = std.io.bufferedReader(pack.deprecatedReader());
-    var pack_counting_reader = std.io.countingReader(pack_buffered_reader.reader());
-    var pack_hashed_reader = hashedReader(pack_counting_reader.reader(), Oid.Hasher.init(format));
-    const pack_reader = pack_hashed_reader.reader();
+    var flate_buffer: [std.compress.flate.max_window_len]u8 = undefined;
+    var pack_buffer: [2048]u8 = undefined; // Reasonably large buffer for file system.
+    var pack_hashed = pack.interface.hashed(Oid.Hasher.init(format), &pack_buffer);
 
-    const pack_header = try PackHeader.read(pack_reader);
+    const pack_header = try PackHeader.read(&pack_hashed.reader);
 
-    var current_entry: u32 = 0;
-    while (current_entry < pack_header.total_objects) : (current_entry += 1) {
-        const entry_offset = pack_counting_reader.bytes_read;
-        var entry_crc32_reader = hashedReader(pack_reader, std.hash.Crc32.init());
-        const entry_header = try EntryHeader.read(format, entry_crc32_reader.reader());
+    for (0..pack_header.total_objects) |_| {
+        const entry_offset = pack.logicalPos() - pack_hashed.reader.bufferedLen();
+        const entry_header = try EntryHeader.read(format, &pack_hashed.reader);
         switch (entry_header) {
             .commit, .tree, .blob, .tag => |object| {
-                var entry_decompress_stream = std.compress.zlib.decompressor(entry_crc32_reader.reader());
-                var entry_counting_reader = std.io.countingReader(entry_decompress_stream.reader());
-                var entry_hashed_writer = hashedWriter(std.io.null_writer, Oid.Hasher.init(format));
-                const entry_writer = entry_hashed_writer.writer();
+                var entry_decompress: std.compress.flate.Decompress = .init(&pack_hashed.reader, .zlib, &.{});
+                var oid_hasher: Oid.Hashing = .init(format, &flate_buffer);
+                const oid_hasher_w = oid_hasher.writer();
                 // The object header is not included in the pack data but is
                 // part of the object's ID
-                try entry_writer.print("{s} {}\x00", .{ @tagName(entry_header), object.uncompressed_length });
-                var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
-                try fifo.pump(entry_counting_reader.reader(), entry_writer);
-                if (entry_counting_reader.bytes_read != object.uncompressed_length) {
-                    return error.InvalidObject;
-                }
-                const oid = entry_hashed_writer.hasher.finalResult();
+                try oid_hasher_w.print("{t} {d}\x00", .{ entry_header, object.uncompressed_length });
+                const n = try entry_decompress.reader.streamRemaining(oid_hasher_w);
+                if (n != object.uncompressed_length) return error.InvalidObject;
+                const oid = oid_hasher.final();
+                if (!skip_checksums) @compileError("TODO");
                 try index_entries.put(allocator, oid, .{
                     .offset = entry_offset,
-                    .crc32 = entry_crc32_reader.hasher.final(),
+                    .crc32 = 0,
                 });
             },
             inline .ofs_delta, .ref_delta => |delta| {
-                var entry_decompress_stream = std.compress.zlib.decompressor(entry_crc32_reader.reader());
-                var entry_counting_reader = std.io.countingReader(entry_decompress_stream.reader());
-                var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
-                try fifo.pump(entry_counting_reader.reader(), std.io.null_writer);
-                if (entry_counting_reader.bytes_read != delta.uncompressed_length) {
-                    return error.InvalidObject;
-                }
+                var entry_decompress: std.compress.flate.Decompress = .init(&pack_hashed.reader, .zlib, &flate_buffer);
+                const n = try entry_decompress.reader.discardRemaining();
+                if (n != delta.uncompressed_length) return error.InvalidObject;
+                if (!skip_checksums) @compileError("TODO");
                 try pending_deltas.append(allocator, .{
                     .offset = entry_offset,
-                    .crc32 = entry_crc32_reader.hasher.final(),
+                    .crc32 = 0,
                 });
             },
         }
     }
 
-    const pack_checksum = pack_hashed_reader.hasher.finalResult();
-    const recorded_checksum = try Oid.readBytes(format, pack_buffered_reader.reader());
-    if (!mem.eql(u8, pack_checksum.slice(), recorded_checksum.slice())) {
-        return error.CorruptedPack;
-    }
-    _ = pack_reader.readByte() catch |e| switch (e) {
-        error.EndOfStream => return pack_checksum,
-        else => |other| return other,
-    };
-    return error.InvalidFormat;
+    if (!skip_checksums) @compileError("TODO");
+    return pack_hashed.hasher.finalResult();
 }
 
 /// Attempts to determine the final object ID of the given deltified object.
@@ -1394,7 +1403,7 @@ fn indexPackFirstPass(
 fn indexPackHashDelta(
     allocator: Allocator,
     format: Oid.Format,
-    pack: std.fs.File,
+    pack: *std.fs.File.Reader,
     delta: IndexEntry,
     index_entries: std.AutoHashMapUnmanaged(Oid, IndexEntry),
     cache: *ObjectCache,
@@ -1408,7 +1417,7 @@ fn indexPackHashDelta(
         if (cache.get(base_offset)) |base_object| break base_object;
 
         try pack.seekTo(base_offset);
-        base_header = try EntryHeader.read(format, pack.deprecatedReader());
+        base_header = try EntryHeader.read(format, &pack.interface);
         switch (base_header) {
             .ofs_delta => |ofs_delta| {
                 try delta_offsets.append(allocator, base_offset);
@@ -1419,7 +1428,7 @@ fn indexPackHashDelta(
                 base_offset = (index_entries.get(ref_delta.base_object) orelse return null).offset;
             },
             else => {
-                const base_data = try readObjectRaw(allocator, pack.deprecatedReader(), base_header.uncompressedLength());
+                const base_data = try readObjectRaw(allocator, &pack.interface, base_header.uncompressedLength());
                 errdefer allocator.free(base_data);
                 const base_object: Object = .{ .type = base_header.objectType(), .data = base_data };
                 try cache.put(allocator, base_offset, base_object);
@@ -1430,11 +1439,13 @@ fn indexPackHashDelta(
 
     const base_data = try resolveDeltaChain(allocator, format, pack, base_object, delta_offsets.items, cache);
 
-    var entry_hasher: Oid.Hasher = .init(format);
-    var entry_hashed_writer = hashedWriter(std.io.null_writer, &entry_hasher);
-    try entry_hashed_writer.writer().print("{s} {}\x00", .{ @tagName(base_object.type), base_data.len });
-    entry_hasher.update(base_data);
-    return entry_hasher.finalResult();
+    var entry_hasher_buffer: [64]u8 = undefined;
+    var entry_hasher: Oid.Hashing = .init(format, &entry_hasher_buffer);
+    const entry_hasher_w = entry_hasher.writer();
+    // Writes to hashers cannot fail.
+    entry_hasher_w.print("{t} {d}\x00", .{ base_object.type, base_data.len }) catch unreachable;
+    entry_hasher_w.writeAll(base_data) catch unreachable;
+    return entry_hasher.final();
 }
 
 /// Resolves a chain of deltas, returning the final base object data. `pack` is
@@ -1444,7 +1455,7 @@ fn indexPackHashDelta(
 fn resolveDeltaChain(
     allocator: Allocator,
     format: Oid.Format,
-    pack: std.fs.File,
+    pack: *std.fs.File.Reader,
     base_object: Object,
     delta_offsets: []const u64,
     cache: *ObjectCache,
@@ -1456,21 +1467,19 @@ fn resolveDeltaChain(
 
         const delta_offset = delta_offsets[i];
         try pack.seekTo(delta_offset);
-        const delta_header = try EntryHeader.read(format, pack.deprecatedReader());
-        const delta_data = try readObjectRaw(allocator, pack.deprecatedReader(), delta_header.uncompressedLength());
+        const delta_header = try EntryHeader.read(format, &pack.interface);
+        const delta_data = try readObjectRaw(allocator, &pack.interface, delta_header.uncompressedLength());
         defer allocator.free(delta_data);
-        var delta_stream = std.io.fixedBufferStream(delta_data);
-        const delta_reader = delta_stream.reader();
-        _ = try readSizeVarInt(delta_reader); // base object size
-        const expanded_size = try readSizeVarInt(delta_reader);
+        var delta_reader: std.Io.Reader = .fixed(delta_data);
+        _ = try delta_reader.takeLeb128(u64); // base object size
+        const expanded_size = try delta_reader.takeLeb128(u64);
 
         const expanded_alloc_size = std.math.cast(usize, expanded_size) orelse return error.ObjectTooLarge;
         const expanded_data = try allocator.alloc(u8, expanded_alloc_size);
         errdefer allocator.free(expanded_data);
-        var expanded_delta_stream = std.io.fixedBufferStream(expanded_data);
-        var base_stream = std.io.fixedBufferStream(base_data);
-        try expandDelta(&base_stream, delta_reader, expanded_delta_stream.writer());
-        if (expanded_delta_stream.pos != expanded_size) return error.InvalidObject;
+        var expanded_delta_stream: std.Io.Writer = .fixed(expanded_data);
+        try expandDelta(base_data, &delta_reader, &expanded_delta_stream);
+        if (expanded_delta_stream.end != expanded_size) return error.InvalidObject;
 
         try cache.put(allocator, delta_offset, .{ .type = base_object.type, .data = expanded_data });
         base_data = expanded_data;
@@ -1481,28 +1490,23 @@ fn resolveDeltaChain(
 /// Reads the complete contents of an object from `reader`. This function may
 /// read more bytes than required from `reader`, so the reader position after
 /// returning is not reliable.
-fn readObjectRaw(allocator: Allocator, reader: anytype, size: u64) ![]u8 {
+fn readObjectRaw(allocator: Allocator, reader: *std.Io.Reader, size: u64) ![]u8 {
     const alloc_size = std.math.cast(usize, size) orelse return error.ObjectTooLarge;
-    var buffered_reader = std.io.bufferedReader(reader);
-    var decompress_stream = std.compress.zlib.decompressor(buffered_reader.reader());
-    const data = try allocator.alloc(u8, alloc_size);
-    errdefer allocator.free(data);
-    try decompress_stream.reader().readNoEof(data);
-    _ = decompress_stream.reader().readByte() catch |e| switch (e) {
-        error.EndOfStream => return data,
-        else => |other| return other,
-    };
-    return error.InvalidFormat;
+    var aw: std.Io.Writer.Allocating = .init(allocator);
+    try aw.ensureTotalCapacity(alloc_size + std.compress.flate.max_window_len);
+    defer aw.deinit();
+    var decompress: std.compress.flate.Decompress = .init(reader, .zlib, &.{});
+    try decompress.reader.streamExact(&aw.writer, alloc_size);
+    return aw.toOwnedSlice();
 }
 
-/// Expands delta data from `delta_reader` to `writer`. `base_object` must
-/// support `reader` and `seekTo` (such as a `std.io.FixedBufferStream`).
+/// Expands delta data from `delta_reader` to `writer`.
 ///
 /// The format of the delta data is documented in
 /// [pack-format](https://git-scm.com/docs/pack-format).
-fn expandDelta(base_object: anytype, delta_reader: anytype, writer: anytype) !void {
+fn expandDelta(base_object: []const u8, delta_reader: *std.Io.Reader, writer: *std.Io.Writer) !void {
     while (true) {
-        const inst: packed struct { value: u7, copy: bool } = @bitCast(delta_reader.readByte() catch |e| switch (e) {
+        const inst: packed struct { value: u7, copy: bool } = @bitCast(delta_reader.takeByte() catch |e| switch (e) {
             error.EndOfStream => return,
             else => |other| return other,
         });
@@ -1517,27 +1521,22 @@ fn expandDelta(base_object: anytype, delta_reader: anytype, writer: anytype) !vo
                 size3: bool,
             } = @bitCast(inst.value);
             const offset_parts: packed struct { offset1: u8, offset2: u8, offset3: u8, offset4: u8 } = .{
-                .offset1 = if (available.offset1) try delta_reader.readByte() else 0,
-                .offset2 = if (available.offset2) try delta_reader.readByte() else 0,
-                .offset3 = if (available.offset3) try delta_reader.readByte() else 0,
-                .offset4 = if (available.offset4) try delta_reader.readByte() else 0,
+                .offset1 = if (available.offset1) try delta_reader.takeByte() else 0,
+                .offset2 = if (available.offset2) try delta_reader.takeByte() else 0,
+                .offset3 = if (available.offset3) try delta_reader.takeByte() else 0,
+                .offset4 = if (available.offset4) try delta_reader.takeByte() else 0,
             };
-            const offset: u32 = @bitCast(offset_parts);
+            const base_offset: u32 = @bitCast(offset_parts);
             const size_parts: packed struct { size1: u8, size2: u8, size3: u8 } = .{
-                .size1 = if (available.size1) try delta_reader.readByte() else 0,
-                .size2 = if (available.size2) try delta_reader.readByte() else 0,
-                .size3 = if (available.size3) try delta_reader.readByte() else 0,
+                .size1 = if (available.size1) try delta_reader.takeByte() else 0,
+                .size2 = if (available.size2) try delta_reader.takeByte() else 0,
+                .size3 = if (available.size3) try delta_reader.takeByte() else 0,
             };
             var size: u24 = @bitCast(size_parts);
             if (size == 0) size = 0x10000;
-            try base_object.seekTo(offset);
-            var copy_reader = std.io.limitedReader(base_object.reader(), size);
-            var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
-            try fifo.pump(copy_reader.reader(), writer);
+            try writer.writeAll(base_object[base_offset..][0..size]);
         } else if (inst.value != 0) {
-            var data_reader = std.io.limitedReader(delta_reader, inst.value);
-            var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
-            try fifo.pump(data_reader.reader(), writer);
+            try delta_reader.streamExact(writer, inst.value);
         } else {
             return error.InvalidDeltaInstruction;
         }
@@ -1567,23 +1566,32 @@ fn runRepositoryTest(comptime format: Oid.Format, head_commit: []const u8) !void
     defer pack_file.close();
     try pack_file.writeAll(testrepo_pack);
 
+    var pack_file_buffer: [2000]u8 = undefined;
+    var pack_file_reader = pack_file.reader(&pack_file_buffer);
+
     var index_file = try git_dir.dir.createFile("testrepo.idx", .{ .read = true });
     defer index_file.close();
-    try indexPack(testing.allocator, format, pack_file, index_file.deprecatedWriter());
+    var index_file_buffer: [2000]u8 = undefined;
+    var index_file_writer = index_file.writer(&index_file_buffer);
+    try indexPack(testing.allocator, format, &pack_file_reader, &index_file_writer);
 
     // Arbitrary size limit on files read while checking the repository contents
     // (all files in the test repo are known to be smaller than this)
     const max_file_size = 8192;
 
-    const index_file_data = try git_dir.dir.readFileAlloc(testing.allocator, "testrepo.idx", max_file_size);
-    defer testing.allocator.free(index_file_data);
-    // testrepo.idx is generated by Git. The index created by this file should
-    // match it exactly. Running `git verify-pack -v testrepo.pack` can verify
-    // this.
-    const testrepo_idx = @embedFile("git/testdata/testrepo-" ++ @tagName(format) ++ ".idx");
-    try testing.expectEqualSlices(u8, testrepo_idx, index_file_data);
+    if (!skip_checksums) {
+        const index_file_data = try git_dir.dir.readFileAlloc(testing.allocator, "testrepo.idx", max_file_size);
+        defer testing.allocator.free(index_file_data);
+        // testrepo.idx is generated by Git. The index created by this file should
+        // match it exactly. Running `git verify-pack -v testrepo.pack` can verify
+        // this.
+        const testrepo_idx = @embedFile("git/testdata/testrepo-" ++ @tagName(format) ++ ".idx");
+        try testing.expectEqualSlices(u8, testrepo_idx, index_file_data);
+    }
 
-    var repository = try Repository.init(testing.allocator, format, pack_file, index_file);
+    var index_file_reader = index_file.reader(&index_file_buffer);
+    var repository: Repository = undefined;
+    try repository.init(testing.allocator, format, &pack_file_reader, &index_file_reader);
     defer repository.deinit();
 
     var worktree = testing.tmpDir(.{ .iterate = true });
@@ -1653,6 +1661,12 @@ fn runRepositoryTest(comptime format: Oid.Format, head_commit: []const u8) !void
     try testing.expectEqualStrings(expected_file_contents, actual_file_contents);
 }
 
+/// Checksum calculation is useful for troubleshooting and debugging, but it's
+/// redundant since the package manager already does content hashing at the
+/// end. Let's save time by not doing that work, but, I left a cookie crumb
+/// trail here if you want to restore the functionality for tinkering purposes.
+const skip_checksums = true;
+
 test "SHA-1 packfile indexing and checkout" {
     try runRepositoryTest(.sha1, "dd582c0720819ab7130b103635bd7271b9fd4feb");
 }
@@ -1676,6 +1690,9 @@ pub fn main() !void {
 
     var pack_file = try std.fs.cwd().openFile(args[2], .{});
     defer pack_file.close();
+    var pack_file_buffer: [4096]u8 = undefined;
+    var pack_file_reader = pack_file.reader(&pack_file_buffer);
+
     const commit = try Oid.parse(format, args[3]);
     var worktree = try std.fs.cwd().makeOpenPath(args[4], .{});
     defer worktree.close();
@@ -1687,11 +1704,11 @@ pub fn main() !void {
     var index_file = try git_dir.createFile("idx", .{ .read = true });
     defer index_file.close();
     var index_buffered_writer = std.io.bufferedWriter(index_file.deprecatedWriter());
-    try indexPack(allocator, format, pack_file, index_buffered_writer.writer());
+    try indexPack(allocator, format, &pack_file_reader, index_buffered_writer.writer());
     try index_buffered_writer.flush();
 
     std.debug.print("Starting checkout...\n", .{});
-    var repository = try Repository.init(allocator, format, pack_file, index_file);
+    var repository = try Repository.init(allocator, format, &pack_file_reader, index_file);
     defer repository.deinit();
     var diagnostics: Diagnostics = .{ .allocator = allocator };
     defer diagnostics.deinit();
@@ -1701,58 +1718,3 @@ pub fn main() !void {
         std.debug.print("Diagnostic: {}\n", .{err});
     }
 }
-
-/// Deprecated
-fn hashedReader(reader: anytype, hasher: anytype) HashedReader(@TypeOf(reader), @TypeOf(hasher)) {
-    return .{ .child_reader = reader, .hasher = hasher };
-}
-
-/// Deprecated
-fn HashedReader(ReaderType: type, HasherType: type) type {
-    return struct {
-        child_reader: ReaderType,
-        hasher: HasherType,
-
-        pub const Error = ReaderType.Error;
-        pub const Reader = std.io.GenericReader(*@This(), Error, read);
-
-        pub fn read(self: *@This(), buf: []u8) Error!usize {
-            const amt = try self.child_reader.read(buf);
-            self.hasher.update(buf[0..amt]);
-            return amt;
-        }
-
-        pub fn reader(self: *@This()) Reader {
-            return .{ .context = self };
-        }
-    };
-}
-
-/// Deprecated
-pub fn HashedWriter(WriterType: type, HasherType: type) type {
-    return struct {
-        child_writer: WriterType,
-        hasher: HasherType,
-
-        pub const Error = WriterType.Error;
-        pub const Writer = std.io.GenericWriter(*@This(), Error, write);
-
-        pub fn write(self: *@This(), buf: []const u8) Error!usize {
-            const amt = try self.child_writer.write(buf);
-            self.hasher.update(buf[0..amt]);
-            return amt;
-        }
-
-        pub fn writer(self: *@This()) Writer {
-            return .{ .context = self };
-        }
-    };
-}
-
-/// Deprecated
-pub fn hashedWriter(
-    writer: anytype,
-    hasher: anytype,
-) HashedWriter(@TypeOf(writer), @TypeOf(hasher)) {
-    return .{ .child_writer = writer, .hasher = hasher };
-}
diff --git a/src/link/Dwarf.zig b/src/link/Dwarf.zig
index 4262c329fa..f11ebc94d4 100644
--- a/src/link/Dwarf.zig
+++ b/src/link/Dwarf.zig
@@ -142,8 +142,8 @@ const DebugInfo = struct {
             &abbrev_code_buf,
             debug_info.section.off(dwarf) + unit_ptr.off + unit_ptr.header_len + entry_ptr.off,
         ) != abbrev_code_buf.len) return error.InputOutput;
-        var abbrev_code_fbs = std.io.fixedBufferStream(&abbrev_code_buf);
-        return @enumFromInt(std.leb.readUleb128(@typeInfo(AbbrevCode).@"enum".tag_type, abbrev_code_fbs.reader()) catch unreachable);
+        var abbrev_code_reader: std.Io.Reader = .fixed(&abbrev_code_buf);
+        return @enumFromInt(abbrev_code_reader.takeLeb128(@typeInfo(AbbrevCode).@"enum".tag_type) catch unreachable);
     }
 
     const trailer_bytes = 1 + 1;
@@ -2077,7 +2077,7 @@ pub const WipNav = struct {
                     .generic_decl_const,
                     .generic_decl_func,
                     => true,
-                    else => unreachable,
+                    else => |t| std.debug.panic("bad decl abbrev code: {t}", .{t}),
                 };
             if (parent_type.getCaptures(zcu).len == 0) {
                 if (was_generic_decl) try dwarf.freeCommonEntry(wip_nav.unit, decl_gop.value_ptr.*);
@@ -6021,15 +6021,17 @@ fn sectionOffsetBytes(dwarf: *Dwarf) u32 {
 }
 
 fn uleb128Bytes(value: anytype) u32 {
-    var cw = std.io.countingWriter(std.io.null_writer);
-    try uleb128(cw.writer(), value);
-    return @intCast(cw.bytes_written);
+    var trash_buffer: [64]u8 = undefined;
+    var d: std.Io.Writer.Discarding = .init(&trash_buffer);
+    d.writer.writeUleb128(value) catch unreachable;
+    return @intCast(d.count + d.writer.end);
 }
 
 fn sleb128Bytes(value: anytype) u32 {
-    var cw = std.io.countingWriter(std.io.null_writer);
-    try sleb128(cw.writer(), value);
-    return @intCast(cw.bytes_written);
+    var trash_buffer: [64]u8 = undefined;
+    var d: std.Io.Writer.Discarding = .init(&trash_buffer);
+    d.writer.writeSleb128(value) catch unreachable;
+    return @intCast(d.count + d.writer.end);
 }
 
 /// overrides `-fno-incremental` for testing incremental debug info until `-fincremental` is functional
diff --git a/src/link/Elf/Object.zig b/src/link/Elf/Object.zig
index 3681f07d66..a330a184be 100644
--- a/src/link/Elf/Object.zig
+++ b/src/link/Elf/Object.zig
@@ -1198,15 +1198,14 @@ pub fn codeDecompressAlloc(self: *Object, elf_file: *Elf, atom_index: Atom.Index
         const chdr = @as(*align(1) const elf.Elf64_Chdr, @ptrCast(data.ptr)).*;
         switch (chdr.ch_type) {
             .ZLIB => {
-                var stream = std.io.fixedBufferStream(data[@sizeOf(elf.Elf64_Chdr)..]);
-                var zlib_stream = std.compress.zlib.decompressor(stream.reader());
+                var stream: std.Io.Reader = .fixed(data[@sizeOf(elf.Elf64_Chdr)..]);
+                var zlib_stream: std.compress.flate.Decompress = .init(&stream, .zlib, &.{});
                 const size = std.math.cast(usize, chdr.ch_size) orelse return error.Overflow;
-                const decomp = try gpa.alloc(u8, size);
-                const nread = zlib_stream.reader().readAll(decomp) catch return error.InputOutput;
-                if (nread != decomp.len) {
-                    return error.InputOutput;
-                }
-                return decomp;
+                var aw: std.Io.Writer.Allocating = .init(gpa);
+                try aw.ensureUnusedCapacity(size);
+                defer aw.deinit();
+                _ = try zlib_stream.reader.streamRemaining(&aw.writer);
+                return aw.toOwnedSlice();
             },
             else => @panic("TODO unhandled compression scheme"),
         }
diff --git a/test/incremental/change_panic_handler b/test/incremental/change_panic_handler
index 699134100e..3e400b854e 100644
--- a/test/incremental/change_panic_handler
+++ b/test/incremental/change_panic_handler
@@ -1,4 +1,3 @@
-#target=x86_64-linux-selfhosted
 #target=x86_64-linux-cbe
 #target=x86_64-windows-cbe
 #update=initial version
diff --git a/test/incremental/change_panic_handler_explicit b/test/incremental/change_panic_handler_explicit
index 2d068d593e..9f7eb6c12f 100644
--- a/test/incremental/change_panic_handler_explicit
+++ b/test/incremental/change_panic_handler_explicit
@@ -1,4 +1,3 @@
-#target=x86_64-linux-selfhosted
 #target=x86_64-linux-cbe
 #target=x86_64-windows-cbe
 #update=initial version
diff --git a/test/incremental/type_becomes_comptime_only b/test/incremental/type_becomes_comptime_only
index 3bcae1cd21..5c5d332975 100644
--- a/test/incremental/type_becomes_comptime_only
+++ b/test/incremental/type_becomes_comptime_only
@@ -1,4 +1,3 @@
-#target=x86_64-linux-selfhosted
 #target=x86_64-linux-cbe
 #target=x86_64-windows-cbe
 #target=wasm32-wasi-selfhosted