Commit 12aa478db0
Changed files (2)
lib
std
compress
zstandard
decode
lib/std/compress/zstandard/decode/block.zig
@@ -654,29 +654,32 @@ pub fn decodeBlock(
bytes_read += fbs.pos;
var bytes_written: usize = 0;
- if (sequences_header.sequence_count > 0) {
+ {
const bit_stream_bytes = src[bytes_read..block_size];
var bit_stream: readers.ReverseBitReader = undefined;
bit_stream.init(bit_stream_bytes) catch return error.MalformedCompressedBlock;
- decode_state.readInitialFseState(&bit_stream) catch return error.MalformedCompressedBlock;
-
- var sequence_size_limit = block_size_max;
- var i: usize = 0;
- while (i < sequences_header.sequence_count) : (i += 1) {
- const write_pos = written_count + bytes_written;
- const decompressed_size = decode_state.decodeSequenceSlice(
- dest,
- write_pos,
- &bit_stream,
- sequence_size_limit,
- i == sequences_header.sequence_count - 1,
- ) catch |err| switch (err) {
- error.DestTooSmall => return error.DestTooSmall,
- else => return error.MalformedCompressedBlock,
- };
- bytes_written += decompressed_size;
- sequence_size_limit -= decompressed_size;
+ if (sequences_header.sequence_count > 0) {
+ decode_state.readInitialFseState(&bit_stream) catch
+ return error.MalformedCompressedBlock;
+
+ var sequence_size_limit = block_size_max;
+ var i: usize = 0;
+ while (i < sequences_header.sequence_count) : (i += 1) {
+ const write_pos = written_count + bytes_written;
+ const decompressed_size = decode_state.decodeSequenceSlice(
+ dest,
+ write_pos,
+ &bit_stream,
+ sequence_size_limit,
+ i == sequences_header.sequence_count - 1,
+ ) catch |err| switch (err) {
+ error.DestTooSmall => return error.DestTooSmall,
+ else => return error.MalformedCompressedBlock,
+ };
+ bytes_written += decompressed_size;
+ sequence_size_limit -= decompressed_size;
+ }
}
if (!bit_stream.isEmpty()) {
@@ -755,24 +758,27 @@ pub fn decodeBlockRingBuffer(
bytes_read += fbs.pos;
var bytes_written: usize = 0;
- if (sequences_header.sequence_count > 0) {
+ {
const bit_stream_bytes = src[bytes_read..block_size];
var bit_stream: readers.ReverseBitReader = undefined;
bit_stream.init(bit_stream_bytes) catch return error.MalformedCompressedBlock;
- decode_state.readInitialFseState(&bit_stream) catch return error.MalformedCompressedBlock;
-
- var sequence_size_limit = block_size_max;
- var i: usize = 0;
- while (i < sequences_header.sequence_count) : (i += 1) {
- const decompressed_size = decode_state.decodeSequenceRingBuffer(
- dest,
- &bit_stream,
- sequence_size_limit,
- i == sequences_header.sequence_count - 1,
- ) catch return error.MalformedCompressedBlock;
- bytes_written += decompressed_size;
- sequence_size_limit -= decompressed_size;
+ if (sequences_header.sequence_count > 0) {
+ decode_state.readInitialFseState(&bit_stream) catch
+ return error.MalformedCompressedBlock;
+
+ var sequence_size_limit = block_size_max;
+ var i: usize = 0;
+ while (i < sequences_header.sequence_count) : (i += 1) {
+ const decompressed_size = decode_state.decodeSequenceRingBuffer(
+ dest,
+ &bit_stream,
+ sequence_size_limit,
+ i == sequences_header.sequence_count - 1,
+ ) catch return error.MalformedCompressedBlock;
+ bytes_written += decompressed_size;
+ sequence_size_limit -= decompressed_size;
+ }
}
if (!bit_stream.isEmpty()) {
@@ -847,28 +853,32 @@ pub fn decodeBlockReader(
try decode_state.prepare(block_reader, literals, sequences_header);
var bytes_written: usize = 0;
- if (sequences_header.sequence_count > 0) {
- if (sequence_buffer.len < block_reader_limited.bytes_left)
- return error.SequenceBufferTooSmall;
-
+ {
const size = try block_reader.readAll(sequence_buffer);
var bit_stream: readers.ReverseBitReader = undefined;
try bit_stream.init(sequence_buffer[0..size]);
- decode_state.readInitialFseState(&bit_stream) catch return error.MalformedCompressedBlock;
-
- var sequence_size_limit = block_size_max;
- var i: usize = 0;
- while (i < sequences_header.sequence_count) : (i += 1) {
- const decompressed_size = decode_state.decodeSequenceRingBuffer(
- dest,
- &bit_stream,
- sequence_size_limit,
- i == sequences_header.sequence_count - 1,
- ) catch return error.MalformedCompressedBlock;
- sequence_size_limit -= decompressed_size;
- bytes_written += decompressed_size;
+ if (sequences_header.sequence_count > 0) {
+ if (sequence_buffer.len < block_reader_limited.bytes_left)
+ return error.SequenceBufferTooSmall;
+
+ decode_state.readInitialFseState(&bit_stream) catch
+ return error.MalformedCompressedBlock;
+
+ var sequence_size_limit = block_size_max;
+ var i: usize = 0;
+ while (i < sequences_header.sequence_count) : (i += 1) {
+ const decompressed_size = decode_state.decodeSequenceRingBuffer(
+ dest,
+ &bit_stream,
+ sequence_size_limit,
+ i == sequences_header.sequence_count - 1,
+ ) catch return error.MalformedCompressedBlock;
+ sequence_size_limit -= decompressed_size;
+ bytes_written += decompressed_size;
+ }
}
+
if (!bit_stream.isEmpty()) {
return error.MalformedCompressedBlock;
}
lib/std/compress/zstandard/readers.zig
@@ -36,8 +36,9 @@ pub const ReverseBitReader = struct {
pub fn init(self: *ReverseBitReader, bytes: []const u8) error{BitStreamHasNoStartBit}!void {
self.byte_reader = ReversedByteReader.init(bytes);
self.bit_reader = std.io.bitReader(.Big, self.byte_reader.reader());
+ if (bytes.len == 0) return;
var i: usize = 0;
- while (i < 8 and 0 == self.readBitsNoEof(u1, 1) catch return error.BitStreamHasNoStartBit) : (i += 1) {}
+ while (i < 8 and 0 == self.readBitsNoEof(u1, 1) catch unreachable) : (i += 1) {}
if (i == 8) return error.BitStreamHasNoStartBit;
}