rocksdb/util/compression.cc
Siddhartha Roychowdhury 21345d2823 Streaming Compression API for WAL compression. (#9619)
Summary:
Implement a streaming compression API (compress/uncompress) to use for WAL compression. The log_writer would use the compress class/API to compress a record before writing it out in chunks. The log_reader would use the uncompress class/API to uncompress the chunks and combine into a single record.

Added unit test to verify the API for different sizes/compression types.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9619

Test Plan: make -j24 check

Reviewed By: anand1976

Differential Revision: D34437346

Pulled By: sidroyc

fbshipit-source-id: b180569ad2ddcf3106380f8758b556cc0ad18382
2022-02-23 23:45:04 -08:00

117 lines
3.6 KiB
C++

// Copyright (c) 2022-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "util/compression.h"
namespace ROCKSDB_NAMESPACE {
StreamingCompress* StreamingCompress::Create(CompressionType compression_type,
const CompressionOptions& opts,
uint32_t compress_format_version,
size_t max_output_len) {
switch (compression_type) {
case kZSTD: {
if (!ZSTD_Streaming_Supported()) {
return nullptr;
}
return new ZSTDStreamingCompress(opts, compress_format_version,
max_output_len);
}
default:
return nullptr;
}
}
StreamingUncompress* StreamingUncompress::Create(
CompressionType compression_type, uint32_t compress_format_version,
size_t max_output_len) {
switch (compression_type) {
case kZSTD: {
if (!ZSTD_Streaming_Supported()) {
return nullptr;
}
return new ZSTDStreamingUncompress(compress_format_version,
max_output_len);
}
default:
return nullptr;
}
}
int ZSTDStreamingCompress::Compress(const char* input, size_t input_size,
char* output, size_t* output_size) {
assert(input != nullptr && output != nullptr && input_size > 0 &&
output_size != nullptr);
*output_size = 0;
#ifndef ZSTD_STREAMING
(void)input;
(void)input_size;
(void)output;
return -1;
#else
if (input_buffer_.src == nullptr || input_buffer_.src != input) {
// New input
// Catch errors where the previous input was not fully decompressed.
assert(input_buffer_.pos == input_buffer_.size);
input_buffer_ = {input, input_size, /*pos=*/0};
} else if (input_buffer_.src == input) {
// Same input, not fully compressed.
}
ZSTD_outBuffer output_buffer = {output, max_output_len_, /*pos=*/0};
const size_t remaining =
ZSTD_compressStream2(cctx_, &output_buffer, &input_buffer_, ZSTD_e_flush);
if (ZSTD_isError(remaining)) {
// Failure
Reset();
return -1;
}
// Success
*output_size = output_buffer.pos;
return (int)(input_buffer_.size - input_buffer_.pos);
#endif
}
void ZSTDStreamingCompress::Reset() {
#ifdef ZSTD_STREAMING
ZSTD_CCtx_reset(cctx_, ZSTD_ResetDirective::ZSTD_reset_session_only);
input_buffer_ = {/*src=*/nullptr, /*size=*/0, /*pos=*/0};
#endif
}
int ZSTDStreamingUncompress::Uncompress(const char* input, size_t input_size,
char* output, size_t* output_size) {
assert(input != nullptr && output != nullptr && input_size > 0 &&
output_size != nullptr);
*output_size = 0;
#ifdef ZSTD_STREAMING
if (input_buffer_.src != input) {
// New input
input_buffer_ = {input, input_size, /*pos=*/0};
}
ZSTD_outBuffer output_buffer = {output, max_output_len_, /*pos=*/0};
size_t ret = ZSTD_decompressStream(dctx_, &output_buffer, &input_buffer_);
if (ZSTD_isError(ret)) {
Reset();
return -1;
}
*output_size = output_buffer.pos;
return (int)(input_buffer_.size - input_buffer_.pos);
#else
(void)input;
(void)input_size;
(void)output;
return -1;
#endif
}
void ZSTDStreamingUncompress::Reset() {
#ifdef ZSTD_STREAMING
ZSTD_DCtx_reset(dctx_, ZSTD_ResetDirective::ZSTD_reset_session_only);
input_buffer_ = {/*src=*/nullptr, /*size=*/0, /*pos=*/0};
#endif
}
} // namespace ROCKSDB_NAMESPACE