std.compress.zstandard: clean up streaming API

This commit is contained in:
dweiller 2023-02-21 14:31:02 +11:00
parent c7c35bf9e6
commit c6ef83efe5

View File

@ -8,10 +8,14 @@ pub const compressed_block = types.compressed_block;
pub const decompress = @import("zstandard/decompress.zig");
pub const DecompressStreamOptions = struct {
verify_checksum: bool = true,
window_size_max: usize = 1 << 23, // 8MiB default maximum window size,
};
pub fn DecompressStream(
comptime ReaderType: type,
comptime verify_checksum: bool,
comptime window_size_max: usize,
comptime options: DecompressStreamOptions,
) type {
return struct {
const Self = @This();
@ -27,7 +31,7 @@ pub fn DecompressStream(
offset_fse_buffer: []types.compressed_block.Table.Fse,
literals_buffer: []u8,
sequence_buffer: []u8,
checksum: if (verify_checksum) ?u32 else void,
checksum: if (options.verify_checksum) ?u32 else void,
current_frame_decompressed_size: usize,
pub const Error = ReaderType.Error || error{
@ -69,8 +73,8 @@ pub fn DecompressStream(
const frame_context = context: {
break :context try decompress.FrameContext.init(
header,
window_size_max,
verify_checksum,
options.window_size_max,
options.verify_checksum,
);
};
@ -99,10 +103,10 @@ pub fn DecompressStream(
);
const buffer = try RingBuffer.init(self.allocator, frame_context.window_size);
const literals_data = try self.allocator.alloc(u8, window_size_max);
const literals_data = try self.allocator.alloc(u8, options.window_size_max);
errdefer self.allocator.free(literals_data);
const sequence_data = try self.allocator.alloc(u8, window_size_max);
const sequence_data = try self.allocator.alloc(u8, options.window_size_max);
errdefer self.allocator.free(sequence_data);
self.literal_fse_buffer = literal_fse_buffer;
@ -116,7 +120,7 @@ pub fn DecompressStream(
self.decode_state = decode_state;
self.frame_context = frame_context;
self.checksum = if (verify_checksum) null else {};
self.checksum = if (options.verify_checksum) null else {};
self.current_frame_decompressed_size = 0;
self.state = .InFrame;
@ -199,7 +203,7 @@ pub fn DecompressStream(
if (self.frame_context.has_checksum) {
const checksum = source_reader.readIntLittle(u32) catch
return error.MalformedFrame;
if (comptime verify_checksum) {
if (comptime options.verify_checksum) {
if (self.frame_context.hasher_opt) |*hasher| {
if (checksum != decompress.computeChecksum(hasher))
return error.ChecksumFailure;
@ -232,17 +236,24 @@ pub fn DecompressStream(
};
}
pub fn decompressStreamOptions(
allocator: Allocator,
reader: anytype,
comptime options: DecompressStreamOptions,
) DecompressStream(@TypeOf(reader, options)) {
return DecompressStream(@TypeOf(reader), options).init(allocator, reader);
}
pub fn decompressStream(
allocator: Allocator,
reader: anytype,
comptime window_size_max: usize,
) DecompressStream(@TypeOf(reader), true, window_size_max) {
return DecompressStream(@TypeOf(reader), true, 8 * (1 << 20)).init(allocator, reader);
) DecompressStream(@TypeOf(reader), .{}) {
return DecompressStream(@TypeOf(reader), .{}).init(allocator, reader);
}
fn testDecompress(data: []const u8) ![]u8 {
var in_stream = std.io.fixedBufferStream(data);
var zstd_stream = decompressStream(std.testing.allocator, in_stream.reader(), 1 << 23);
var zstd_stream = decompressStream(std.testing.allocator, in_stream.reader());
defer zstd_stream.deinit();
const result = zstd_stream.reader().readAllAlloc(std.testing.allocator, std.math.maxInt(usize));
return result;