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06b44a0afa
- flatten std.crypto.hash.Sha1 and give it a writable interface that optimizes splats - flatten std.hash.crc and give it a writable interface that optimizes splats - remove old writer impls from std.crypto - add fs.File.Writer.moveToReader - add fs.File.Writer.seekTo - add std.io.Reader.Hashed and std.io.Writer.Hashed which are passthrough streams. Instead of passing through to null writer, use the writable interface implemented directly on hashers which doesn't have to account for passing through the data. - add std.io.BufferedWriter.writeSplatAll
71 lines
1.9 KiB
Zig
71 lines
1.9 KiB
Zig
//! A `Writer` that discards all data.
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const std = @import("../../std.zig");
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const Writer = std.io.Writer;
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const NullWriter = @This();
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err: ?Error = null,
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pub const Error = std.fs.File.StatError;
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pub fn writer(nw: *NullWriter) Writer {
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return .{
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.context = nw,
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.vtable = &.{
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.writeSplat = writeSplat,
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.writeFile = writeFile,
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},
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};
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}
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pub fn writable(nw: *NullWriter, buffer: []u8) std.io.BufferedWriter {
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return writer(nw).buffered(buffer);
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}
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fn writeSplat(context: ?*anyopaque, data: []const []const u8, splat: usize) Writer.Error!usize {
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_ = context;
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const headers = data[0 .. data.len - 1];
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const pattern = data[headers.len..];
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var written: usize = pattern.len * splat;
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for (headers) |bytes| written += bytes.len;
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return written;
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}
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fn writeFile(
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context: ?*anyopaque,
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file: std.fs.File,
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offset: Writer.Offset,
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limit: Writer.Limit,
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headers_and_trailers: []const []const u8,
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headers_len: usize,
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) Writer.FileError!usize {
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const nw: *NullWriter = @alignCast(@ptrCast(context));
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var n: usize = 0;
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if (offset == .none) {
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@panic("TODO seek the file forwards");
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}
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const limit_int = limit.toInt() orelse {
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const headers = headers_and_trailers[0..headers_len];
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for (headers) |bytes| n += bytes.len;
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if (offset.toInt()) |off| {
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const stat = file.stat() catch |err| {
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nw.err = err;
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return error.WriteFailed;
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};
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n += stat.size - off;
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for (headers_and_trailers[headers_len..]) |bytes| n += bytes.len;
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return n;
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}
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@panic("TODO stream from file until eof, counting");
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};
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for (headers_and_trailers) |bytes| n += bytes.len;
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return limit_int + n;
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}
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test "writing a small string" {
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var nw: NullWriter = undefined;
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var bw = nw.writer().unbuffered();
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try bw.writeAll("yay");
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}
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