Commit 67b3e07260
Changed files (3)
lib
std
compress
lib/std/compress/zlib.zig
@@ -8,7 +8,19 @@ const testing = std.testing;
const mem = std.mem;
const deflate = std.compress.deflate;
-pub fn ZlibStreamReader(comptime ReaderType: type) type {
+// Zlib header format as specified in RFC1950
+const ZLibHeader = packed struct {
+ checksum: u5,
+ preset_dict: u1,
+ compression_level: u2,
+ compression_method: u4,
+ compression_info: u4,
+
+ const DEFLATE = 8;
+ const WINDOW_32K = 7;
+};
+
+pub fn DecompressStream(comptime ReaderType: type) type {
return struct {
const Self = @This();
@@ -24,26 +36,24 @@ pub fn ZlibStreamReader(comptime ReaderType: type) type {
fn init(allocator: mem.Allocator, source: ReaderType) !Self {
// Zlib header format is specified in RFC1950
- const header = try source.readBytesNoEof(2);
+ const header_u16 = try source.readIntBig(u16);
- const CM = @truncate(u4, header[0]);
- const CINFO = @truncate(u4, header[0] >> 4);
- const FCHECK = @truncate(u5, header[1]);
- _ = FCHECK;
- const FDICT = @truncate(u1, header[1] >> 5);
-
- if ((@as(u16, header[0]) << 8 | header[1]) % 31 != 0)
+ // verify the header checksum
+ if (header_u16 % 31 != 0)
return error.BadHeader;
+ const header = @bitCast(ZLibHeader, header_u16);
// The CM field must be 8 to indicate the use of DEFLATE
- if (CM != 8) return error.InvalidCompression;
+ if (header.compression_method != ZLibHeader.DEFLATE)
+ return error.InvalidCompression;
// CINFO is the base-2 logarithm of the LZ77 window size, minus 8.
// Values above 7 are unspecified and therefore rejected.
- if (CINFO > 7) return error.InvalidWindowSize;
+ if (header.compression_info > ZLibHeader.WINDOW_32K)
+ return error.InvalidWindowSize;
const dictionary = null;
// TODO: Support this case
- if (FDICT != 0)
+ if (header.preset_dict != 0)
return error.Unsupported;
return Self{
@@ -84,8 +94,8 @@ pub fn ZlibStreamReader(comptime ReaderType: type) type {
};
}
-pub fn zlibStreamReader(allocator: mem.Allocator, reader: anytype) !ZlibStreamReader(@TypeOf(reader)) {
- return ZlibStreamReader(@TypeOf(reader)).init(allocator, reader);
+pub fn decompressStream(allocator: mem.Allocator, reader: anytype) !DecompressStream(@TypeOf(reader)) {
+ return DecompressStream(@TypeOf(reader)).init(allocator, reader);
}
pub const CompressionLevel = enum(u2) {
@@ -95,11 +105,11 @@ pub const CompressionLevel = enum(u2) {
maximum = 3,
};
-pub const CompressionOptions = struct {
+pub const CompressStreamOptions = struct {
level: CompressionLevel = .default,
};
-pub fn ZlibStreamWriter(comptime WriterType: type) type {
+pub fn CompressStream(comptime WriterType: type) type {
return struct {
const Self = @This();
@@ -112,17 +122,17 @@ pub fn ZlibStreamWriter(comptime WriterType: type) type {
in_writer: WriterType,
hasher: std.hash.Adler32,
- fn init(allocator: mem.Allocator, dest: WriterType, options: CompressionOptions) !Self {
- // Zlib header format is specified in RFC1950
- const CM: u4 = 8; // DEFLATE
- const CINFO: u4 = 7; // 32K window
- const CMF: u8 = (@as(u8, CINFO) << 4) | CM;
+ fn init(allocator: mem.Allocator, dest: WriterType, options: CompressStreamOptions) !Self {
+ var header = ZLibHeader{
+ .compression_info = ZLibHeader.WINDOW_32K,
+ .compression_method = ZLibHeader.DEFLATE,
+ .compression_level = @enumToInt(options.level),
+ .preset_dict = 0,
+ .checksum = 0,
+ };
+ header.checksum = @truncate(u5, 31 - @bitCast(u16, header) % 31);
- const FLEVEL: u2 = @enumToInt(options.level);
- const FDICT: u1 = 0; // No preset dictionary support
- const FLG_temp = (@as(u8, FLEVEL) << 6) | (@as(u8, FDICT) << 5);
- const FCHECK: u5 = 31 - ((@as(u16, CMF) * 256 + FLG_temp) % 31);
- const FLG = FLG_temp | FCHECK;
+ try dest.writeIntBig(u16, @bitCast(u16, header));
const compression_level: deflate.Compression = switch (options.level) {
.no_compression => .no_compression,
@@ -131,8 +141,6 @@ pub fn ZlibStreamWriter(comptime WriterType: type) type {
.maximum => .best_compression,
};
- try dest.writeAll(&.{ CMF, FLG });
-
return Self{
.allocator = allocator,
.deflator = try deflate.compressor(allocator, dest, .{ .level = compression_level }),
@@ -160,7 +168,7 @@ pub fn ZlibStreamWriter(comptime WriterType: type) type {
self.deflator.deinit();
}
- pub fn close(self: *Self) !void {
+ pub fn finish(self: *Self) !void {
const hash = self.hasher.final();
try self.deflator.close();
try self.in_writer.writeIntBig(u32, hash);
@@ -168,15 +176,14 @@ pub fn ZlibStreamWriter(comptime WriterType: type) type {
};
}
-pub fn zlibStreamWriter(allocator: mem.Allocator, writer: anytype, options: CompressionOptions) !ZlibStreamWriter(@TypeOf(writer)) {
- return ZlibStreamWriter(@TypeOf(writer)).init(allocator, writer, options);
+pub fn compressStream(allocator: mem.Allocator, writer: anytype, options: CompressStreamOptions) !CompressStream(@TypeOf(writer)) {
+ return CompressStream(@TypeOf(writer)).init(allocator, writer, options);
}
-
-fn testReader(data: []const u8, expected: []const u8) !void {
+fn testDecompress(data: []const u8, expected: []const u8) !void {
var in_stream = io.fixedBufferStream(data);
- var zlib_stream = try zlibStreamReader(testing.allocator, in_stream.reader());
+ var zlib_stream = try decompressStream(testing.allocator, in_stream.reader());
defer zlib_stream.deinit();
// Read and decompress the whole file
@@ -195,24 +202,24 @@ test "compressed data" {
const rfc1951_txt = @embedFile("testdata/rfc1951.txt");
// Compressed with compression level = 0
- try testReader(
+ try testDecompress(
@embedFile("testdata/rfc1951.txt.z.0"),
rfc1951_txt,
);
// Compressed with compression level = 9
- try testReader(
+ try testDecompress(
@embedFile("testdata/rfc1951.txt.z.9"),
rfc1951_txt,
);
// Compressed with compression level = 9 and fixed Huffman codes
- try testReader(
+ try testDecompress(
@embedFile("testdata/rfc1951.txt.fixed.z.9"),
rfc1951_txt,
);
}
test "don't read past deflate stream's end" {
- try testReader(&[_]u8{
+ try testDecompress(&[_]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,
@@ -227,32 +234,32 @@ test "sanity checks" {
// Truncated header
try testing.expectError(
error.EndOfStream,
- testReader(&[_]u8{0x78}, ""),
+ testDecompress(&[_]u8{0x78}, ""),
);
// Failed FCHECK check
try testing.expectError(
error.BadHeader,
- testReader(&[_]u8{ 0x78, 0x9D }, ""),
+ testDecompress(&[_]u8{ 0x78, 0x9D }, ""),
);
// Wrong CM
try testing.expectError(
error.InvalidCompression,
- testReader(&[_]u8{ 0x79, 0x94 }, ""),
+ testDecompress(&[_]u8{ 0x79, 0x94 }, ""),
);
// Wrong CINFO
try testing.expectError(
error.InvalidWindowSize,
- testReader(&[_]u8{ 0x88, 0x98 }, ""),
+ testDecompress(&[_]u8{ 0x88, 0x98 }, ""),
);
// Wrong checksum
try testing.expectError(
error.WrongChecksum,
- testReader(&[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00 }, ""),
+ testDecompress(&[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00 }, ""),
);
// Truncated checksum
try testing.expectError(
error.EndOfStream,
- testReader(&[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00 }, ""),
+ testDecompress(&[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00 }, ""),
);
}
@@ -260,14 +267,16 @@ test "compress data" {
const allocator = testing.allocator;
const rfc1951_txt = @embedFile("testdata/rfc1951.txt");
- var compressed_data = std.ArrayList(u8).init(allocator);
- defer compressed_data.deinit();
+ for (std.meta.tags(CompressionLevel)) |level| {
+ var compressed_data = std.ArrayList(u8).init(allocator);
+ defer compressed_data.deinit();
- var compressor = try zlibStreamWriter(allocator, compressed_data.writer(), .{});
- defer compressor.deinit();
+ var compressor = try compressStream(allocator, compressed_data.writer(), .{ .level = level });
+ defer compressor.deinit();
- try compressor.writer().writeAll(rfc1951_txt);
- try compressor.close();
+ try compressor.writer().writeAll(rfc1951_txt);
+ try compressor.finish();
- try testReader(compressed_data.items, rfc1951_txt);
+ try testDecompress(compressed_data.items, rfc1951_txt);
+ }
}
lib/std/http/Client.zig
@@ -309,7 +309,7 @@ pub const RequestTransfer = union(enum) {
/// The decompressor for response messages.
pub const Compression = union(enum) {
- pub const DeflateDecompressor = std.compress.zlib.ZlibStream(Request.TransferReader);
+ pub const DeflateDecompressor = std.compress.zlib.DecompressStream(Request.TransferReader);
pub const GzipDecompressor = std.compress.gzip.Decompress(Request.TransferReader);
pub const ZstdDecompressor = std.compress.zstd.DecompressStream(Request.TransferReader, .{});
@@ -722,7 +722,7 @@ pub const Request = struct {
if (req.response.transfer_compression) |tc| switch (tc) {
.compress => return error.CompressionNotSupported,
.deflate => req.response.compression = .{
- .deflate = std.compress.zlib.zlibStream(req.client.allocator, req.transferReader()) catch return error.CompressionInitializationFailed,
+ .deflate = std.compress.zlib.decompressStream(req.client.allocator, req.transferReader()) catch return error.CompressionInitializationFailed,
},
.gzip => req.response.compression = .{
.gzip = std.compress.gzip.decompress(req.client.allocator, req.transferReader()) catch return error.CompressionInitializationFailed,
lib/std/http/Server.zig
@@ -155,7 +155,7 @@ pub const ResponseTransfer = union(enum) {
/// The decompressor for request messages.
pub const Compression = union(enum) {
- pub const DeflateDecompressor = std.compress.zlib.ZlibStream(Response.TransferReader);
+ pub const DeflateDecompressor = std.compress.zlib.DecompressStream(Response.TransferReader);
pub const GzipDecompressor = std.compress.gzip.Decompress(Response.TransferReader);
pub const ZstdDecompressor = std.compress.zstd.DecompressStream(Response.TransferReader, .{});
@@ -520,7 +520,7 @@ pub const Response = struct {
if (res.request.transfer_compression) |tc| switch (tc) {
.compress => return error.CompressionNotSupported,
.deflate => res.request.compression = .{
- .deflate = std.compress.zlib.zlibStream(res.allocator, res.transferReader()) catch return error.CompressionInitializationFailed,
+ .deflate = std.compress.zlib.decompressStream(res.allocator, res.transferReader()) catch return error.CompressionInitializationFailed,
},
.gzip => res.request.compression = .{
.gzip = std.compress.gzip.decompress(res.allocator, res.transferReader()) catch return error.CompressionInitializationFailed,