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rocksdb/util/compression.h

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// Copyright (c) 2011-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).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
#pragma once
#include <algorithm>
#include <limits>
#ifdef ROCKSDB_MALLOC_USABLE_SIZE
#ifdef OS_FREEBSD
#include <malloc_np.h>
#else // OS_FREEBSD
#include <malloc.h>
#endif // OS_FREEBSD
#endif // ROCKSDB_MALLOC_USABLE_SIZE
#include <string>
#include "memory/memory_allocator.h"
#include "rocksdb/options.h"
#include "rocksdb/table.h"
#include "test_util/sync_point.h"
#include "util/coding.h"
#include "util/compression_context_cache.h"
#include "util/string_util.h"
#ifdef SNAPPY
#include <snappy.h>
#endif
#ifdef ZLIB
#include <zlib.h>
#endif
#ifdef BZIP2
#include <bzlib.h>
#endif
#if defined(LZ4)
#include <lz4.h>
#include <lz4hc.h>
#endif
#if defined(ZSTD)
#include <zstd.h>
#if ZSTD_VERSION_NUMBER >= 10103 // v1.1.3+
#include <zdict.h>
#define ZSTD_STREAMING
#endif // ZSTD_VERSION_NUMBER >= 10103
namespace ROCKSDB_NAMESPACE {
// Need this for the context allocation override
// On windows we need to do this explicitly
#if (ZSTD_VERSION_NUMBER >= 500)
#if defined(ROCKSDB_JEMALLOC) && defined(OS_WIN) && \
defined(ZSTD_STATIC_LINKING_ONLY)
#define ROCKSDB_ZSTD_CUSTOM_MEM
namespace port {
ZSTD_customMem GetJeZstdAllocationOverrides();
} // namespace port
#endif // defined(ROCKSDB_JEMALLOC) && defined(OS_WIN) &&
// defined(ZSTD_STATIC_LINKING_ONLY)
// We require `ZSTD_sizeof_DDict` and `ZSTD_createDDict_byReference` to use
// `ZSTD_DDict`. The former was introduced in v1.0.0 and the latter was
// introduced in v1.1.3. But an important bug fix for `ZSTD_sizeof_DDict` came
// in v1.1.4, so that is the version we require. As of today's latest version
// (v1.3.8), they are both still in the experimental API, which means they are
// only exported when the compiler flag `ZSTD_STATIC_LINKING_ONLY` is set.
#if defined(ZSTD_STATIC_LINKING_ONLY) && ZSTD_VERSION_NUMBER >= 10104
#define ROCKSDB_ZSTD_DDICT
#endif // defined(ZSTD_STATIC_LINKING_ONLY) && ZSTD_VERSION_NUMBER >= 10104
// Cached data represents a portion that can be re-used
// If, in the future we have more than one native context to
// cache we can arrange this as a tuple
class ZSTDUncompressCachedData {
public:
using ZSTDNativeContext = ZSTD_DCtx*;
ZSTDUncompressCachedData() {}
// Init from cache
ZSTDUncompressCachedData(const ZSTDUncompressCachedData& o) = delete;
ZSTDUncompressCachedData& operator=(const ZSTDUncompressCachedData&) = delete;
ZSTDUncompressCachedData(ZSTDUncompressCachedData&& o) ROCKSDB_NOEXCEPT
: ZSTDUncompressCachedData() {
*this = std::move(o);
}
ZSTDUncompressCachedData& operator=(ZSTDUncompressCachedData&& o)
ROCKSDB_NOEXCEPT {
assert(zstd_ctx_ == nullptr);
std::swap(zstd_ctx_, o.zstd_ctx_);
std::swap(cache_idx_, o.cache_idx_);
return *this;
}
ZSTDNativeContext Get() const { return zstd_ctx_; }
int64_t GetCacheIndex() const { return cache_idx_; }
void CreateIfNeeded() {
if (zstd_ctx_ == nullptr) {
#ifdef ROCKSDB_ZSTD_CUSTOM_MEM
zstd_ctx_ =
ZSTD_createDCtx_advanced(port::GetJeZstdAllocationOverrides());
#else // ROCKSDB_ZSTD_CUSTOM_MEM
zstd_ctx_ = ZSTD_createDCtx();
#endif // ROCKSDB_ZSTD_CUSTOM_MEM
cache_idx_ = -1;
}
}
void InitFromCache(const ZSTDUncompressCachedData& o, int64_t idx) {
zstd_ctx_ = o.zstd_ctx_;
cache_idx_ = idx;
}
~ZSTDUncompressCachedData() {
if (zstd_ctx_ != nullptr && cache_idx_ == -1) {
ZSTD_freeDCtx(zstd_ctx_);
}
}
private:
ZSTDNativeContext zstd_ctx_ = nullptr;
int64_t cache_idx_ = -1; // -1 means this instance owns the context
};
#endif // (ZSTD_VERSION_NUMBER >= 500)
} // namespace ROCKSDB_NAMESPACE
#endif // ZSTD
#if !(defined ZSTD) || !(ZSTD_VERSION_NUMBER >= 500)
namespace ROCKSDB_NAMESPACE {
class ZSTDUncompressCachedData {
void* padding; // unused
public:
using ZSTDNativeContext = void*;
ZSTDUncompressCachedData() {}
ZSTDUncompressCachedData(const ZSTDUncompressCachedData&) {}
ZSTDUncompressCachedData& operator=(const ZSTDUncompressCachedData&) = delete;
ZSTDUncompressCachedData(ZSTDUncompressCachedData&&)
ROCKSDB_NOEXCEPT = default;
ZSTDUncompressCachedData& operator=(ZSTDUncompressCachedData&&)
ROCKSDB_NOEXCEPT = default;
ZSTDNativeContext Get() const { return nullptr; }
int64_t GetCacheIndex() const { return -1; }
void CreateIfNeeded() {}
void InitFromCache(const ZSTDUncompressCachedData&, int64_t) {}
private:
void ignore_padding__() { padding = nullptr; }
};
} // namespace ROCKSDB_NAMESPACE
#endif
#if defined(XPRESS)
#include "port/xpress.h"
#endif
namespace ROCKSDB_NAMESPACE {
// Holds dictionary and related data, like ZSTD's digested compression
// dictionary.
struct CompressionDict {
#if ZSTD_VERSION_NUMBER >= 700
ZSTD_CDict* zstd_cdict_ = nullptr;
#endif // ZSTD_VERSION_NUMBER >= 700
std::string dict_;
public:
#if ZSTD_VERSION_NUMBER >= 700
CompressionDict(std::string dict, CompressionType type, int level) {
#else // ZSTD_VERSION_NUMBER >= 700
CompressionDict(std::string dict, CompressionType /*type*/, int /*level*/) {
#endif // ZSTD_VERSION_NUMBER >= 700
dict_ = std::move(dict);
#if ZSTD_VERSION_NUMBER >= 700
zstd_cdict_ = nullptr;
if (!dict_.empty() && (type == kZSTD || type == kZSTDNotFinalCompression)) {
if (level == CompressionOptions::kDefaultCompressionLevel) {
// 3 is the value of ZSTD_CLEVEL_DEFAULT (not exposed publicly), see
// https://github.com/facebook/zstd/issues/1148
level = 3;
}
// Should be safe (but slower) if below call fails as we'll use the
// raw dictionary to compress.
zstd_cdict_ = ZSTD_createCDict(dict_.data(), dict_.size(), level);
assert(zstd_cdict_ != nullptr);
}
#endif // ZSTD_VERSION_NUMBER >= 700
}
~CompressionDict() {
#if ZSTD_VERSION_NUMBER >= 700
size_t res = 0;
if (zstd_cdict_ != nullptr) {
res = ZSTD_freeCDict(zstd_cdict_);
}
assert(res == 0); // Last I checked they can't fail
(void)res; // prevent unused var warning
#endif // ZSTD_VERSION_NUMBER >= 700
}
#if ZSTD_VERSION_NUMBER >= 700
const ZSTD_CDict* GetDigestedZstdCDict() const { return zstd_cdict_; }
#endif // ZSTD_VERSION_NUMBER >= 700
Slice GetRawDict() const { return dict_; }
static const CompressionDict& GetEmptyDict() {
static CompressionDict empty_dict{};
return empty_dict;
}
CompressionDict() = default;
// Disable copy/move
CompressionDict(const CompressionDict&) = delete;
CompressionDict& operator=(const CompressionDict&) = delete;
CompressionDict(CompressionDict&&) = delete;
CompressionDict& operator=(CompressionDict&&) = delete;
};
// Holds dictionary and related data, like ZSTD's digested uncompression
// dictionary.
struct UncompressionDict {
// Block containing the data for the compression dictionary in case the
// constructor that takes a string parameter is used.
std::string dict_;
// Block containing the data for the compression dictionary in case the
// constructor that takes a Slice parameter is used and the passed in
// CacheAllocationPtr is not nullptr.
CacheAllocationPtr allocation_;
// Slice pointing to the compression dictionary data. Can point to
// dict_, allocation_, or some other memory location, depending on how
// the object was constructed.
Slice slice_;
#ifdef ROCKSDB_ZSTD_DDICT
// Processed version of the contents of slice_ for ZSTD compression.
ZSTD_DDict* zstd_ddict_ = nullptr;
#endif // ROCKSDB_ZSTD_DDICT
#ifdef ROCKSDB_ZSTD_DDICT
UncompressionDict(std::string dict, bool using_zstd)
#else // ROCKSDB_ZSTD_DDICT
UncompressionDict(std::string dict, bool /* using_zstd */)
#endif // ROCKSDB_ZSTD_DDICT
: dict_(std::move(dict)), slice_(dict_) {
#ifdef ROCKSDB_ZSTD_DDICT
if (!slice_.empty() && using_zstd) {
zstd_ddict_ = ZSTD_createDDict_byReference(slice_.data(), slice_.size());
assert(zstd_ddict_ != nullptr);
}
#endif // ROCKSDB_ZSTD_DDICT
}
#ifdef ROCKSDB_ZSTD_DDICT
UncompressionDict(Slice slice, CacheAllocationPtr&& allocation,
bool using_zstd)
#else // ROCKSDB_ZSTD_DDICT
UncompressionDict(Slice slice, CacheAllocationPtr&& allocation,
bool /* using_zstd */)
#endif // ROCKSDB_ZSTD_DDICT
: allocation_(std::move(allocation)), slice_(std::move(slice)) {
#ifdef ROCKSDB_ZSTD_DDICT
if (!slice_.empty() && using_zstd) {
zstd_ddict_ = ZSTD_createDDict_byReference(slice_.data(), slice_.size());
assert(zstd_ddict_ != nullptr);
}
#endif // ROCKSDB_ZSTD_DDICT
}
UncompressionDict(UncompressionDict&& rhs)
: dict_(std::move(rhs.dict_)),
allocation_(std::move(rhs.allocation_)),
slice_(std::move(rhs.slice_))
#ifdef ROCKSDB_ZSTD_DDICT
,
zstd_ddict_(rhs.zstd_ddict_)
#endif
{
#ifdef ROCKSDB_ZSTD_DDICT
rhs.zstd_ddict_ = nullptr;
#endif
}
~UncompressionDict() {
#ifdef ROCKSDB_ZSTD_DDICT
size_t res = 0;
if (zstd_ddict_ != nullptr) {
res = ZSTD_freeDDict(zstd_ddict_);
}
assert(res == 0); // Last I checked they can't fail
(void)res; // prevent unused var warning
#endif // ROCKSDB_ZSTD_DDICT
}
UncompressionDict& operator=(UncompressionDict&& rhs) {
if (this == &rhs) {
return *this;
}
dict_ = std::move(rhs.dict_);
allocation_ = std::move(rhs.allocation_);
slice_ = std::move(rhs.slice_);
#ifdef ROCKSDB_ZSTD_DDICT
zstd_ddict_ = rhs.zstd_ddict_;
rhs.zstd_ddict_ = nullptr;
#endif
return *this;
}
// The object is self-contained if the string constructor is used, or the
// Slice constructor is invoked with a non-null allocation. Otherwise, it
// is the caller's responsibility to ensure that the underlying storage
// outlives this object.
bool own_bytes() const { return !dict_.empty() || allocation_; }
const Slice& GetRawDict() const { return slice_; }
#ifdef ROCKSDB_ZSTD_DDICT
const ZSTD_DDict* GetDigestedZstdDDict() const { return zstd_ddict_; }
#endif // ROCKSDB_ZSTD_DDICT
static const UncompressionDict& GetEmptyDict() {
static UncompressionDict empty_dict{};
return empty_dict;
}
size_t ApproximateMemoryUsage() const {
size_t usage = sizeof(struct UncompressionDict);
usage += dict_.size();
if (allocation_) {
auto allocator = allocation_.get_deleter().allocator;
if (allocator) {
usage += allocator->UsableSize(allocation_.get(), slice_.size());
} else {
usage += slice_.size();
}
}
#ifdef ROCKSDB_ZSTD_DDICT
usage += ZSTD_sizeof_DDict(zstd_ddict_);
#endif // ROCKSDB_ZSTD_DDICT
return usage;
}
UncompressionDict() = default;
// Disable copy
UncompressionDict(const CompressionDict&) = delete;
UncompressionDict& operator=(const CompressionDict&) = delete;
};
class CompressionContext {
private:
#if defined(ZSTD) && (ZSTD_VERSION_NUMBER >= 500)
ZSTD_CCtx* zstd_ctx_ = nullptr;
void CreateNativeContext(CompressionType type) {
if (type == kZSTD || type == kZSTDNotFinalCompression) {
#ifdef ROCKSDB_ZSTD_CUSTOM_MEM
zstd_ctx_ =
ZSTD_createCCtx_advanced(port::GetJeZstdAllocationOverrides());
#else // ROCKSDB_ZSTD_CUSTOM_MEM
zstd_ctx_ = ZSTD_createCCtx();
#endif // ROCKSDB_ZSTD_CUSTOM_MEM
}
}
void DestroyNativeContext() {
if (zstd_ctx_ != nullptr) {
ZSTD_freeCCtx(zstd_ctx_);
}
}
public:
// callable inside ZSTD_Compress
ZSTD_CCtx* ZSTDPreallocCtx() const {
assert(zstd_ctx_ != nullptr);
return zstd_ctx_;
}
#else // ZSTD && (ZSTD_VERSION_NUMBER >= 500)
private:
void CreateNativeContext(CompressionType /* type */) {}
void DestroyNativeContext() {}
#endif // ZSTD && (ZSTD_VERSION_NUMBER >= 500)
public:
explicit CompressionContext(CompressionType type) {
CreateNativeContext(type);
}
~CompressionContext() { DestroyNativeContext(); }
CompressionContext(const CompressionContext&) = delete;
CompressionContext& operator=(const CompressionContext&) = delete;
};
class CompressionInfo {
const CompressionOptions& opts_;
const CompressionContext& context_;
const CompressionDict& dict_;
const CompressionType type_;
const uint64_t sample_for_compression_;
public:
CompressionInfo(const CompressionOptions& _opts,
const CompressionContext& _context,
const CompressionDict& _dict, CompressionType _type,
uint64_t _sample_for_compression)
: opts_(_opts),
context_(_context),
dict_(_dict),
type_(_type),
sample_for_compression_(_sample_for_compression) {}
const CompressionOptions& options() const { return opts_; }
const CompressionContext& context() const { return context_; }
const CompressionDict& dict() const { return dict_; }
CompressionType type() const { return type_; }
uint64_t SampleForCompression() const { return sample_for_compression_; }
};
class UncompressionContext {
private:
CompressionContextCache* ctx_cache_ = nullptr;
ZSTDUncompressCachedData uncomp_cached_data_;
public:
explicit UncompressionContext(CompressionType type) {
if (type == kZSTD || type == kZSTDNotFinalCompression) {
ctx_cache_ = CompressionContextCache::Instance();
uncomp_cached_data_ = ctx_cache_->GetCachedZSTDUncompressData();
}
}
~UncompressionContext() {
if (uncomp_cached_data_.GetCacheIndex() != -1) {
assert(ctx_cache_ != nullptr);
ctx_cache_->ReturnCachedZSTDUncompressData(
uncomp_cached_data_.GetCacheIndex());
}
}
UncompressionContext(const UncompressionContext&) = delete;
UncompressionContext& operator=(const UncompressionContext&) = delete;
ZSTDUncompressCachedData::ZSTDNativeContext GetZSTDContext() const {
return uncomp_cached_data_.Get();
}
};
class UncompressionInfo {
const UncompressionContext& context_;
const UncompressionDict& dict_;
const CompressionType type_;
public:
UncompressionInfo(const UncompressionContext& _context,
const UncompressionDict& _dict, CompressionType _type)
: context_(_context), dict_(_dict), type_(_type) {}
const UncompressionContext& context() const { return context_; }
const UncompressionDict& dict() const { return dict_; }
CompressionType type() const { return type_; }
};
inline bool Snappy_Supported() {
#ifdef SNAPPY
return true;
#else
return false;
#endif
}
inline bool Zlib_Supported() {
#ifdef ZLIB
return true;
#else
return false;
#endif
}
inline bool BZip2_Supported() {
#ifdef BZIP2
return true;
#else
return false;
#endif
}
inline bool LZ4_Supported() {
#ifdef LZ4
return true;
#else
return false;
#endif
}
inline bool XPRESS_Supported() {
#ifdef XPRESS
return true;
#else
return false;
#endif
}
inline bool ZSTD_Supported() {
#ifdef ZSTD
// ZSTD format is finalized since version 0.8.0.
return (ZSTD_versionNumber() >= 800);
#else
return false;
#endif
}
inline bool ZSTDNotFinal_Supported() {
#ifdef ZSTD
return true;
#else
return false;
#endif
}
inline bool ZSTD_Streaming_Supported() {
#ifdef ZSTD
return ZSTD_versionNumber() >= 10300;
#else
return false;
#endif
}
inline bool StreamingCompressionTypeSupported(
CompressionType compression_type) {
switch (compression_type) {
case kNoCompression:
return true;
case kZSTD:
return ZSTD_Streaming_Supported();
default:
return false;
}
}
inline bool CompressionTypeSupported(CompressionType compression_type) {
switch (compression_type) {
case kNoCompression:
return true;
case kSnappyCompression:
return Snappy_Supported();
case kZlibCompression:
return Zlib_Supported();
case kBZip2Compression:
return BZip2_Supported();
case kLZ4Compression:
return LZ4_Supported();
case kLZ4HCCompression:
return LZ4_Supported();
case kXpressCompression:
return XPRESS_Supported();
case kZSTDNotFinalCompression:
return ZSTDNotFinal_Supported();
case kZSTD:
return ZSTD_Supported();
default:
assert(false);
return false;
}
}
inline bool DictCompressionTypeSupported(CompressionType compression_type) {
switch (compression_type) {
case kNoCompression:
return false;
case kSnappyCompression:
return false;
case kZlibCompression:
return Zlib_Supported();
case kBZip2Compression:
return false;
case kLZ4Compression:
case kLZ4HCCompression:
#if LZ4_VERSION_NUMBER >= 10400 // r124+
return LZ4_Supported();
#else
return false;
#endif
case kXpressCompression:
return false;
case kZSTDNotFinalCompression:
#if ZSTD_VERSION_NUMBER >= 500 // v0.5.0+
return ZSTDNotFinal_Supported();
#else
return false;
#endif
case kZSTD:
#if ZSTD_VERSION_NUMBER >= 500 // v0.5.0+
return ZSTD_Supported();
#else
return false;
#endif
default:
assert(false);
return false;
}
}
inline std::string CompressionTypeToString(CompressionType compression_type) {
switch (compression_type) {
case kNoCompression:
return "NoCompression";
case kSnappyCompression:
return "Snappy";
case kZlibCompression:
return "Zlib";
case kBZip2Compression:
return "BZip2";
case kLZ4Compression:
return "LZ4";
case kLZ4HCCompression:
return "LZ4HC";
case kXpressCompression:
return "Xpress";
case kZSTD:
return "ZSTD";
case kZSTDNotFinalCompression:
return "ZSTDNotFinal";
case kDisableCompressionOption:
return "DisableOption";
default:
assert(false);
return "";
}
}
inline std::string CompressionOptionsToString(
CompressionOptions& compression_options) {
std::string result;
result.reserve(512);
result.append("window_bits=")
.append(ToString(compression_options.window_bits))
.append("; ");
result.append("level=")
.append(ToString(compression_options.level))
.append("; ");
result.append("strategy=")
.append(ToString(compression_options.strategy))
.append("; ");
result.append("max_dict_bytes=")
.append(ToString(compression_options.max_dict_bytes))
.append("; ");
result.append("zstd_max_train_bytes=")
.append(ToString(compression_options.zstd_max_train_bytes))
.append("; ");
result.append("enabled=")
.append(ToString(compression_options.enabled))
.append("; ");
result.append("max_dict_buffer_bytes=")
.append(ToString(compression_options.max_dict_buffer_bytes))
.append("; ");
return result;
}
// compress_format_version can have two values:
// 1 -- decompressed sizes for BZip2 and Zlib are not included in the compressed
// block. Also, decompressed sizes for LZ4 are encoded in platform-dependent
// way.
// 2 -- Zlib, BZip2 and LZ4 encode decompressed size as Varint32 just before the
// start of compressed block. Snappy format is the same as version 1.
inline bool Snappy_Compress(const CompressionInfo& /*info*/, const char* input,
size_t length, ::std::string* output) {
#ifdef SNAPPY
output->resize(snappy::MaxCompressedLength(length));
size_t outlen;
snappy::RawCompress(input, length, &(*output)[0], &outlen);
output->resize(outlen);
return true;
#else
(void)input;
(void)length;
(void)output;
return false;
#endif
}
inline CacheAllocationPtr Snappy_Uncompress(
const char* input, size_t length, size_t* uncompressed_size,
MemoryAllocator* allocator = nullptr) {
#ifdef SNAPPY
size_t uncompressed_length = 0;
if (!snappy::GetUncompressedLength(input, length, &uncompressed_length)) {
return nullptr;
}
CacheAllocationPtr output = AllocateBlock(uncompressed_length, allocator);
if (!snappy::RawUncompress(input, length, output.get())) {
return nullptr;
}
*uncompressed_size = uncompressed_length;
return output;
#else
(void)input;
(void)length;
(void)uncompressed_size;
(void)allocator;
return nullptr;
#endif
}
namespace compression {
// returns size
inline size_t PutDecompressedSizeInfo(std::string* output, uint32_t length) {
PutVarint32(output, length);
return output->size();
}
inline bool GetDecompressedSizeInfo(const char** input_data,
size_t* input_length,
uint32_t* output_len) {
auto new_input_data =
GetVarint32Ptr(*input_data, *input_data + *input_length, output_len);
if (new_input_data == nullptr) {
return false;
}
*input_length -= (new_input_data - *input_data);
*input_data = new_input_data;
return true;
}
} // namespace compression
// compress_format_version == 1 -- decompressed size is not included in the
// block header
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline bool Zlib_Compress(const CompressionInfo& info,
uint32_t compress_format_version, const char* input,
size_t length, ::std::string* output) {
#ifdef ZLIB
if (length > std::numeric_limits<uint32_t>::max()) {
// Can't compress more than 4GB
return false;
}
size_t output_header_len = 0;
if (compress_format_version == 2) {
output_header_len = compression::PutDecompressedSizeInfo(
output, static_cast<uint32_t>(length));
}
// The memLevel parameter specifies how much memory should be allocated for
// the internal compression state.
// memLevel=1 uses minimum memory but is slow and reduces compression ratio.
// memLevel=9 uses maximum memory for optimal speed.
// The default value is 8. See zconf.h for more details.
static const int memLevel = 8;
int level;
if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
level = Z_DEFAULT_COMPRESSION;
} else {
level = info.options().level;
}
z_stream _stream;
memset(&_stream, 0, sizeof(z_stream));
int st = deflateInit2(&_stream, level, Z_DEFLATED, info.options().window_bits,
memLevel, info.options().strategy);
if (st != Z_OK) {
return false;
}
Slice compression_dict = info.dict().GetRawDict();
if (compression_dict.size()) {
// Initialize the compression library's dictionary
st = deflateSetDictionary(
&_stream, reinterpret_cast<const Bytef*>(compression_dict.data()),
static_cast<unsigned int>(compression_dict.size()));
if (st != Z_OK) {
deflateEnd(&_stream);
return false;
}
}
// Get an upper bound on the compressed size.
size_t upper_bound =
deflateBound(&_stream, static_cast<unsigned long>(length));
output->resize(output_header_len + upper_bound);
// Compress the input, and put compressed data in output.
_stream.next_in = (Bytef*)input;
_stream.avail_in = static_cast<unsigned int>(length);
// Initialize the output size.
_stream.avail_out = static_cast<unsigned int>(upper_bound);
_stream.next_out = reinterpret_cast<Bytef*>(&(*output)[output_header_len]);
bool compressed = false;
st = deflate(&_stream, Z_FINISH);
if (st == Z_STREAM_END) {
compressed = true;
output->resize(output->size() - _stream.avail_out);
}
// The only return value we really care about is Z_STREAM_END.
// Z_OK means insufficient output space. This means the compression is
// bigger than decompressed size. Just fail the compression in that case.
deflateEnd(&_stream);
return compressed;
#else
(void)info;
(void)compress_format_version;
(void)input;
(void)length;
(void)output;
return false;
#endif
}
// compress_format_version == 1 -- decompressed size is not included in the
// block header
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline CacheAllocationPtr Zlib_Uncompress(
const UncompressionInfo& info, const char* input_data, size_t input_length,
size_t* uncompressed_size, uint32_t compress_format_version,
MemoryAllocator* allocator = nullptr, int windowBits = -14) {
#ifdef ZLIB
uint32_t output_len = 0;
if (compress_format_version == 2) {
if (!compression::GetDecompressedSizeInfo(&input_data, &input_length,
&output_len)) {
return nullptr;
}
} else {
// Assume the decompressed data size will 5x of compressed size, but round
// to the page size
size_t proposed_output_len = ((input_length * 5) & (~(4096 - 1))) + 4096;
output_len = static_cast<uint32_t>(
std::min(proposed_output_len,
static_cast<size_t>(std::numeric_limits<uint32_t>::max())));
}
z_stream _stream;
memset(&_stream, 0, sizeof(z_stream));
// For raw inflate, the windowBits should be -8..-15.
// If windowBits is bigger than zero, it will use either zlib
// header or gzip header. Adding 32 to it will do automatic detection.
int st =
inflateInit2(&_stream, windowBits > 0 ? windowBits + 32 : windowBits);
if (st != Z_OK) {
return nullptr;
}
const Slice& compression_dict = info.dict().GetRawDict();
if (compression_dict.size()) {
// Initialize the compression library's dictionary
st = inflateSetDictionary(
&_stream, reinterpret_cast<const Bytef*>(compression_dict.data()),
static_cast<unsigned int>(compression_dict.size()));
if (st != Z_OK) {
return nullptr;
}
}
_stream.next_in = (Bytef*)input_data;
_stream.avail_in = static_cast<unsigned int>(input_length);
auto output = AllocateBlock(output_len, allocator);
_stream.next_out = (Bytef*)output.get();
_stream.avail_out = static_cast<unsigned int>(output_len);
bool done = false;
while (!done) {
st = inflate(&_stream, Z_SYNC_FLUSH);
switch (st) {
case Z_STREAM_END:
done = true;
break;
case Z_OK: {
// No output space. Increase the output space by 20%.
// We should never run out of output space if
// compress_format_version == 2
assert(compress_format_version != 2);
size_t old_sz = output_len;
uint32_t output_len_delta = output_len / 5;
output_len += output_len_delta < 10 ? 10 : output_len_delta;
auto tmp = AllocateBlock(output_len, allocator);
memcpy(tmp.get(), output.get(), old_sz);
output = std::move(tmp);
// Set more output.
_stream.next_out = (Bytef*)(output.get() + old_sz);
_stream.avail_out = static_cast<unsigned int>(output_len - old_sz);
break;
}
case Z_BUF_ERROR:
default:
inflateEnd(&_stream);
return nullptr;
}
}
// If we encoded decompressed block size, we should have no bytes left
assert(compress_format_version != 2 || _stream.avail_out == 0);
assert(output_len >= _stream.avail_out);
*uncompressed_size = output_len - _stream.avail_out;
inflateEnd(&_stream);
return output;
#else
(void)info;
(void)input_data;
(void)input_length;
(void)uncompressed_size;
(void)compress_format_version;
(void)allocator;
(void)windowBits;
return nullptr;
#endif
}
// compress_format_version == 1 -- decompressed size is not included in the
// block header
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
inline bool BZip2_Compress(const CompressionInfo& /*info*/,
uint32_t compress_format_version, const char* input,
size_t length, ::std::string* output) {
#ifdef BZIP2
if (length > std::numeric_limits<uint32_t>::max()) {
// Can't compress more than 4GB
return false;
}
size_t output_header_len = 0;
if (compress_format_version == 2) {
output_header_len = compression::PutDecompressedSizeInfo(
output, static_cast<uint32_t>(length));
}
// Resize output to be the plain data length.
// This may not be big enough if the compression actually expands data.
output->resize(output_header_len + length);
bz_stream _stream;
memset(&_stream, 0, sizeof(bz_stream));
// Block size 1 is 100K.
// 0 is for silent.
// 30 is the default workFactor
int st = BZ2_bzCompressInit(&_stream, 1, 0, 30);
if (st != BZ_OK) {
return false;
}
// Compress the input, and put compressed data in output.
_stream.next_in = (char*)input;
_stream.avail_in = static_cast<unsigned int>(length);
// Initialize the output size.
_stream.avail_out = static_cast<unsigned int>(length);
_stream.next_out = reinterpret_cast<char*>(&(*output)[output_header_len]);
bool compressed = false;
st = BZ2_bzCompress(&_stream, BZ_FINISH);
if (st == BZ_STREAM_END) {
compressed = true;
output->resize(output->size() - _stream.avail_out);
}
// The only return value we really care about is BZ_STREAM_END.
// BZ_FINISH_OK means insufficient output space. This means the compression
// is bigger than decompressed size. Just fail the compression in that case.
BZ2_bzCompressEnd(&_stream);
return compressed;
#else
(void)compress_format_version;
(void)input;
(void)length;
(void)output;
return false;
#endif
}
// compress_format_version == 1 -- decompressed size is not included in the
// block header
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
inline CacheAllocationPtr BZip2_Uncompress(
const char* input_data, size_t input_length, size_t* uncompressed_size,
uint32_t compress_format_version, MemoryAllocator* allocator = nullptr) {
#ifdef BZIP2
uint32_t output_len = 0;
if (compress_format_version == 2) {
if (!compression::GetDecompressedSizeInfo(&input_data, &input_length,
&output_len)) {
return nullptr;
}
} else {
// Assume the decompressed data size will 5x of compressed size, but round
// to the next page size
size_t proposed_output_len = ((input_length * 5) & (~(4096 - 1))) + 4096;
output_len = static_cast<uint32_t>(
std::min(proposed_output_len,
static_cast<size_t>(std::numeric_limits<uint32_t>::max())));
}
bz_stream _stream;
memset(&_stream, 0, sizeof(bz_stream));
int st = BZ2_bzDecompressInit(&_stream, 0, 0);
if (st != BZ_OK) {
return nullptr;
}
_stream.next_in = (char*)input_data;
_stream.avail_in = static_cast<unsigned int>(input_length);
auto output = AllocateBlock(output_len, allocator);
_stream.next_out = (char*)output.get();
_stream.avail_out = static_cast<unsigned int>(output_len);
bool done = false;
while (!done) {
st = BZ2_bzDecompress(&_stream);
switch (st) {
case BZ_STREAM_END:
done = true;
break;
case BZ_OK: {
// No output space. Increase the output space by 20%.
// We should never run out of output space if
// compress_format_version == 2
assert(compress_format_version != 2);
uint32_t old_sz = output_len;
output_len = output_len * 1.2;
auto tmp = AllocateBlock(output_len, allocator);
memcpy(tmp.get(), output.get(), old_sz);
output = std::move(tmp);
// Set more output.
_stream.next_out = (char*)(output.get() + old_sz);
_stream.avail_out = static_cast<unsigned int>(output_len - old_sz);
break;
}
default:
BZ2_bzDecompressEnd(&_stream);
return nullptr;
}
}
// If we encoded decompressed block size, we should have no bytes left
assert(compress_format_version != 2 || _stream.avail_out == 0);
assert(output_len >= _stream.avail_out);
*uncompressed_size = output_len - _stream.avail_out;
BZ2_bzDecompressEnd(&_stream);
return output;
#else
(void)input_data;
(void)input_length;
(void)uncompressed_size;
(void)compress_format_version;
(void)allocator;
return nullptr;
#endif
}
// compress_format_version == 1 -- decompressed size is included in the
// block header using memcpy, which makes database non-portable)
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline bool LZ4_Compress(const CompressionInfo& info,
uint32_t compress_format_version, const char* input,
size_t length, ::std::string* output) {
#ifdef LZ4
if (length > std::numeric_limits<uint32_t>::max()) {
// Can't compress more than 4GB
return false;
}
size_t output_header_len = 0;
if (compress_format_version == 2) {
// new encoding, using varint32 to store size information
output_header_len = compression::PutDecompressedSizeInfo(
output, static_cast<uint32_t>(length));
} else {
// legacy encoding, which is not really portable (depends on big/little
// endianness)
output_header_len = 8;
output->resize(output_header_len);
char* p = const_cast<char*>(output->c_str());
memcpy(p, &length, sizeof(length));
}
int compress_bound = LZ4_compressBound(static_cast<int>(length));
output->resize(static_cast<size_t>(output_header_len + compress_bound));
int outlen;
#if LZ4_VERSION_NUMBER >= 10400 // r124+
LZ4_stream_t* stream = LZ4_createStream();
Slice compression_dict = info.dict().GetRawDict();
if (compression_dict.size()) {
LZ4_loadDict(stream, compression_dict.data(),
static_cast<int>(compression_dict.size()));
}
#if LZ4_VERSION_NUMBER >= 10700 // r129+
outlen =
LZ4_compress_fast_continue(stream, input, &(*output)[output_header_len],
static_cast<int>(length), compress_bound, 1);
#else // up to r128
outlen = LZ4_compress_limitedOutput_continue(
stream, input, &(*output)[output_header_len], static_cast<int>(length),
compress_bound);
#endif
LZ4_freeStream(stream);
#else // up to r123
outlen = LZ4_compress_limitedOutput(input, &(*output)[output_header_len],
static_cast<int>(length), compress_bound);
#endif // LZ4_VERSION_NUMBER >= 10400
if (outlen == 0) {
return false;
}
output->resize(static_cast<size_t>(output_header_len + outlen));
return true;
#else // LZ4
(void)info;
(void)compress_format_version;
(void)input;
(void)length;
(void)output;
return false;
#endif
}
// compress_format_version == 1 -- decompressed size is included in the
// block header using memcpy, which makes database non-portable)
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline CacheAllocationPtr LZ4_Uncompress(const UncompressionInfo& info,
const char* input_data,
size_t input_length,
size_t* uncompressed_size,
uint32_t compress_format_version,
MemoryAllocator* allocator = nullptr) {
#ifdef LZ4
uint32_t output_len = 0;
if (compress_format_version == 2) {
// new encoding, using varint32 to store size information
if (!compression::GetDecompressedSizeInfo(&input_data, &input_length,
&output_len)) {
return nullptr;
}
} else {
// legacy encoding, which is not really portable (depends on big/little
// endianness)
if (input_length < 8) {
return nullptr;
}
if (port::kLittleEndian) {
memcpy(&output_len, input_data, sizeof(output_len));
} else {
memcpy(&output_len, input_data + 4, sizeof(output_len));
}
input_length -= 8;
input_data += 8;
}
auto output = AllocateBlock(output_len, allocator);
int decompress_bytes = 0;
#if LZ4_VERSION_NUMBER >= 10400 // r124+
LZ4_streamDecode_t* stream = LZ4_createStreamDecode();
const Slice& compression_dict = info.dict().GetRawDict();
if (compression_dict.size()) {
LZ4_setStreamDecode(stream, compression_dict.data(),
static_cast<int>(compression_dict.size()));
}
decompress_bytes = LZ4_decompress_safe_continue(
stream, input_data, output.get(), static_cast<int>(input_length),
static_cast<int>(output_len));
LZ4_freeStreamDecode(stream);
#else // up to r123
decompress_bytes = LZ4_decompress_safe(input_data, output.get(),
static_cast<int>(input_length),
static_cast<int>(output_len));
#endif // LZ4_VERSION_NUMBER >= 10400
if (decompress_bytes < 0) {
return nullptr;
}
assert(decompress_bytes == static_cast<int>(output_len));
*uncompressed_size = decompress_bytes;
return output;
#else // LZ4
(void)info;
(void)input_data;
(void)input_length;
(void)uncompressed_size;
(void)compress_format_version;
(void)allocator;
return nullptr;
#endif
}
// compress_format_version == 1 -- decompressed size is included in the
// block header using memcpy, which makes database non-portable)
// compress_format_version == 2 -- decompressed size is included in the block
// header in varint32 format
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline bool LZ4HC_Compress(const CompressionInfo& info,
uint32_t compress_format_version, const char* input,
size_t length, ::std::string* output) {
#ifdef LZ4
if (length > std::numeric_limits<uint32_t>::max()) {
// Can't compress more than 4GB
return false;
}
size_t output_header_len = 0;
if (compress_format_version == 2) {
// new encoding, using varint32 to store size information
output_header_len = compression::PutDecompressedSizeInfo(
output, static_cast<uint32_t>(length));
} else {
// legacy encoding, which is not really portable (depends on big/little
// endianness)
output_header_len = 8;
output->resize(output_header_len);
char* p = const_cast<char*>(output->c_str());
memcpy(p, &length, sizeof(length));
}
int compress_bound = LZ4_compressBound(static_cast<int>(length));
output->resize(static_cast<size_t>(output_header_len + compress_bound));
int outlen;
int level;
if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
level = 0; // lz4hc.h says any value < 1 will be sanitized to default
} else {
level = info.options().level;
}
#if LZ4_VERSION_NUMBER >= 10400 // r124+
LZ4_streamHC_t* stream = LZ4_createStreamHC();
LZ4_resetStreamHC(stream, level);
Slice compression_dict = info.dict().GetRawDict();
const char* compression_dict_data =
compression_dict.size() > 0 ? compression_dict.data() : nullptr;
size_t compression_dict_size = compression_dict.size();
if (compression_dict_data != nullptr) {
LZ4_loadDictHC(stream, compression_dict_data,
static_cast<int>(compression_dict_size));
}
#if LZ4_VERSION_NUMBER >= 10700 // r129+
outlen =
LZ4_compress_HC_continue(stream, input, &(*output)[output_header_len],
static_cast<int>(length), compress_bound);
#else // r124-r128
outlen = LZ4_compressHC_limitedOutput_continue(
stream, input, &(*output)[output_header_len], static_cast<int>(length),
compress_bound);
#endif // LZ4_VERSION_NUMBER >= 10700
LZ4_freeStreamHC(stream);
#elif LZ4_VERSION_MAJOR // r113-r123
outlen = LZ4_compressHC2_limitedOutput(input, &(*output)[output_header_len],
static_cast<int>(length),
compress_bound, level);
#else // up to r112
outlen =
LZ4_compressHC_limitedOutput(input, &(*output)[output_header_len],
static_cast<int>(length), compress_bound);
#endif // LZ4_VERSION_NUMBER >= 10400
if (outlen == 0) {
return false;
}
output->resize(static_cast<size_t>(output_header_len + outlen));
return true;
#else // LZ4
(void)info;
(void)compress_format_version;
(void)input;
(void)length;
(void)output;
return false;
#endif
}
#ifdef XPRESS
inline bool XPRESS_Compress(const char* input, size_t length,
std::string* output) {
return port::xpress::Compress(input, length, output);
}
#else
inline bool XPRESS_Compress(const char* /*input*/, size_t /*length*/,
std::string* /*output*/) {
return false;
}
#endif
#ifdef XPRESS
inline char* XPRESS_Uncompress(const char* input_data, size_t input_length,
size_t* uncompressed_size) {
return port::xpress::Decompress(input_data, input_length, uncompressed_size);
}
#else
inline char* XPRESS_Uncompress(const char* /*input_data*/,
size_t /*input_length*/,
size_t* /*uncompressed_size*/) {
return nullptr;
}
#endif
inline bool ZSTD_Compress(const CompressionInfo& info, const char* input,
size_t length, ::std::string* output) {
#ifdef ZSTD
if (length > std::numeric_limits<uint32_t>::max()) {
// Can't compress more than 4GB
return false;
}
size_t output_header_len = compression::PutDecompressedSizeInfo(
output, static_cast<uint32_t>(length));
size_t compressBound = ZSTD_compressBound(length);
output->resize(static_cast<size_t>(output_header_len + compressBound));
size_t outlen = 0;
int level;
if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
// 3 is the value of ZSTD_CLEVEL_DEFAULT (not exposed publicly), see
// https://github.com/facebook/zstd/issues/1148
level = 3;
} else {
level = info.options().level;
}
#if ZSTD_VERSION_NUMBER >= 500 // v0.5.0+
ZSTD_CCtx* context = info.context().ZSTDPreallocCtx();
assert(context != nullptr);
#if ZSTD_VERSION_NUMBER >= 700 // v0.7.0+
if (info.dict().GetDigestedZstdCDict() != nullptr) {
outlen = ZSTD_compress_usingCDict(context, &(*output)[output_header_len],
compressBound, input, length,
info.dict().GetDigestedZstdCDict());
}
#endif // ZSTD_VERSION_NUMBER >= 700
if (outlen == 0) {
outlen = ZSTD_compress_usingDict(context, &(*output)[output_header_len],
compressBound, input, length,
info.dict().GetRawDict().data(),
info.dict().GetRawDict().size(), level);
}
#else // up to v0.4.x
outlen = ZSTD_compress(&(*output)[output_header_len], compressBound, input,
length, level);
#endif // ZSTD_VERSION_NUMBER >= 500
if (outlen == 0) {
return false;
}
output->resize(output_header_len + outlen);
return true;
#else // ZSTD
(void)info;
(void)input;
(void)length;
(void)output;
return false;
#endif
}
// @param compression_dict Data for presetting the compression library's
// dictionary.
inline CacheAllocationPtr ZSTD_Uncompress(
const UncompressionInfo& info, const char* input_data, size_t input_length,
size_t* uncompressed_size, MemoryAllocator* allocator = nullptr) {
#ifdef ZSTD
uint32_t output_len = 0;
if (!compression::GetDecompressedSizeInfo(&input_data, &input_length,
&output_len)) {
return nullptr;
}
auto output = AllocateBlock(output_len, allocator);
size_t actual_output_length = 0;
#if ZSTD_VERSION_NUMBER >= 500 // v0.5.0+
ZSTD_DCtx* context = info.context().GetZSTDContext();
assert(context != nullptr);
#ifdef ROCKSDB_ZSTD_DDICT
if (info.dict().GetDigestedZstdDDict() != nullptr) {
actual_output_length = ZSTD_decompress_usingDDict(
context, output.get(), output_len, input_data, input_length,
info.dict().GetDigestedZstdDDict());
}
#endif // ROCKSDB_ZSTD_DDICT
if (actual_output_length == 0) {
actual_output_length = ZSTD_decompress_usingDict(
context, output.get(), output_len, input_data, input_length,
info.dict().GetRawDict().data(), info.dict().GetRawDict().size());
}
#else // up to v0.4.x
(void)info;
actual_output_length =
ZSTD_decompress(output.get(), output_len, input_data, input_length);
#endif // ZSTD_VERSION_NUMBER >= 500
assert(actual_output_length == output_len);
*uncompressed_size = actual_output_length;
return output;
#else // ZSTD
(void)info;
(void)input_data;
(void)input_length;
(void)uncompressed_size;
(void)allocator;
return nullptr;
#endif
}
inline bool ZSTD_TrainDictionarySupported() {
#ifdef ZSTD
// Dictionary trainer is available since v0.6.1 for static linking, but not
// available for dynamic linking until v1.1.3. For now we enable the feature
// in v1.1.3+ only.
return (ZSTD_versionNumber() >= 10103);
#else
return false;
#endif
}
inline std::string ZSTD_TrainDictionary(const std::string& samples,
const std::vector<size_t>& sample_lens,
size_t max_dict_bytes) {
// Dictionary trainer is available since v0.6.1 for static linking, but not
// available for dynamic linking until v1.1.3. For now we enable the feature
// in v1.1.3+ only.
#if ZSTD_VERSION_NUMBER >= 10103 // v1.1.3+
assert(samples.empty() == sample_lens.empty());
if (samples.empty()) {
return "";
}
std::string dict_data(max_dict_bytes, '\0');
size_t dict_len = ZDICT_trainFromBuffer(
&dict_data[0], max_dict_bytes, &samples[0], &sample_lens[0],
static_cast<unsigned>(sample_lens.size()));
if (ZDICT_isError(dict_len)) {
return "";
}
assert(dict_len <= max_dict_bytes);
dict_data.resize(dict_len);
return dict_data;
#else // up to v1.1.2
assert(false);
(void)samples;
(void)sample_lens;
(void)max_dict_bytes;
return "";
#endif // ZSTD_VERSION_NUMBER >= 10103
}
inline std::string ZSTD_TrainDictionary(const std::string& samples,
size_t sample_len_shift,
size_t max_dict_bytes) {
// Dictionary trainer is available since v0.6.1, but ZSTD was marked stable
// only since v0.8.0. For now we enable the feature in stable versions only.
#if ZSTD_VERSION_NUMBER >= 10103 // v1.1.3+
// skips potential partial sample at the end of "samples"
size_t num_samples = samples.size() >> sample_len_shift;
std::vector<size_t> sample_lens(num_samples, size_t(1) << sample_len_shift);
return ZSTD_TrainDictionary(samples, sample_lens, max_dict_bytes);
#else // up to v1.1.2
assert(false);
(void)samples;
(void)sample_len_shift;
(void)max_dict_bytes;
return "";
#endif // ZSTD_VERSION_NUMBER >= 10103
}
inline bool CompressData(const Slice& raw,
const CompressionInfo& compression_info,
uint32_t compress_format_version,
std::string* compressed_output) {
bool ret = false;
// Will return compressed block contents if (1) the compression method is
// supported in this platform and (2) the compression rate is "good enough".
switch (compression_info.type()) {
case kSnappyCompression:
ret = Snappy_Compress(compression_info, raw.data(), raw.size(),
compressed_output);
break;
case kZlibCompression:
ret = Zlib_Compress(compression_info, compress_format_version, raw.data(),
raw.size(), compressed_output);
break;
case kBZip2Compression:
ret = BZip2_Compress(compression_info, compress_format_version,
raw.data(), raw.size(), compressed_output);
break;
case kLZ4Compression:
ret = LZ4_Compress(compression_info, compress_format_version, raw.data(),
raw.size(), compressed_output);
break;
case kLZ4HCCompression:
ret = LZ4HC_Compress(compression_info, compress_format_version,
raw.data(), raw.size(), compressed_output);
break;
case kXpressCompression:
ret = XPRESS_Compress(raw.data(), raw.size(), compressed_output);
break;
case kZSTD:
case kZSTDNotFinalCompression:
ret = ZSTD_Compress(compression_info, raw.data(), raw.size(),
compressed_output);
break;
default:
// Do not recognize this compression type
break;
}
TEST_SYNC_POINT_CALLBACK("CompressData:TamperWithReturnValue",
static_cast<void*>(&ret));
return ret;
}
inline CacheAllocationPtr UncompressData(
const UncompressionInfo& uncompression_info, const char* data, size_t n,
size_t* uncompressed_size, uint32_t compress_format_version,
MemoryAllocator* allocator = nullptr) {
switch (uncompression_info.type()) {
case kSnappyCompression:
return Snappy_Uncompress(data, n, uncompressed_size, allocator);
case kZlibCompression:
return Zlib_Uncompress(uncompression_info, data, n, uncompressed_size,
compress_format_version, allocator);
case kBZip2Compression:
return BZip2_Uncompress(data, n, uncompressed_size,
compress_format_version, allocator);
case kLZ4Compression:
case kLZ4HCCompression:
return LZ4_Uncompress(uncompression_info, data, n, uncompressed_size,
compress_format_version, allocator);
case kXpressCompression:
// XPRESS allocates memory internally, thus no support for custom
// allocator.
return CacheAllocationPtr(XPRESS_Uncompress(data, n, uncompressed_size));
case kZSTD:
case kZSTDNotFinalCompression:
return ZSTD_Uncompress(uncompression_info, data, n, uncompressed_size,
allocator);
default:
return CacheAllocationPtr();
}
}
// Records the compression type for subsequent WAL records.
class CompressionTypeRecord {
public:
explicit CompressionTypeRecord(CompressionType compression_type)
: compression_type_(compression_type) {}
CompressionType GetCompressionType() const { return compression_type_; }
inline void EncodeTo(std::string* dst) const {
assert(dst != nullptr);
PutFixed32(dst, compression_type_);
}
inline Status DecodeFrom(Slice* src) {
constexpr char class_name[] = "CompressionTypeRecord";
uint32_t val;
if (!GetFixed32(src, &val)) {
return Status::Corruption(class_name,
"Error decoding WAL compression type");
}
CompressionType compression_type = static_cast<CompressionType>(val);
if (!StreamingCompressionTypeSupported(compression_type)) {
return Status::Corruption(class_name,
"WAL compression type not supported");
}
compression_type_ = compression_type;
return Status::OK();
}
inline std::string DebugString() const {
return "compression_type: " + CompressionTypeToString(compression_type_);
}
private:
CompressionType compression_type_;
};
// Base class to implement compression for a stream of buffers.
// Instantiate an implementation of the class using Create() with the
// compression type and use Compress() repeatedly.
// The output buffer needs to be at least max_output_len.
// Call Reset() in between frame boundaries or in case of an error.
// NOTE: This class is not thread safe.
class StreamingCompress {
public:
StreamingCompress(CompressionType compression_type,
const CompressionOptions& opts,
uint32_t compress_format_version, size_t max_output_len)
: compression_type_(compression_type),
opts_(opts),
compress_format_version_(compress_format_version),
max_output_len_(max_output_len) {}
virtual ~StreamingCompress() = default;
// compress should be called repeatedly with the same input till the method
// returns 0
// Parameters:
// input - buffer to compress
// input_size - size of input buffer
// output - compressed buffer allocated by caller, should be at least
// max_output_len
// output_size - size of the output buffer
// Returns -1 for errors, the remaining size of the input buffer that needs to
// be compressed
virtual int Compress(const char* input, size_t input_size, char* output,
size_t* output_pos) = 0;
// static method to create object of a class inherited from StreamingCompress
// based on the actual compression type.
static StreamingCompress* Create(CompressionType compression_type,
const CompressionOptions& opts,
uint32_t compress_format_version,
size_t max_output_len);
virtual void Reset() = 0;
protected:
const CompressionType compression_type_;
const CompressionOptions opts_;
const uint32_t compress_format_version_;
const size_t max_output_len_;
};
// Base class to uncompress a stream of compressed buffers.
// Instantiate an implementation of the class using Create() with the
// compression type and use Uncompress() repeatedly.
// The output buffer needs to be at least max_output_len.
// Call Reset() in between frame boundaries or in case of an error.
// NOTE: This class is not thread safe.
class StreamingUncompress {
public:
StreamingUncompress(CompressionType compression_type,
uint32_t compress_format_version, size_t max_output_len)
: compression_type_(compression_type),
compress_format_version_(compress_format_version),
max_output_len_(max_output_len) {}
virtual ~StreamingUncompress() = default;
// uncompress should be called again with the same input if output_size is
// equal to max_output_len or with the next input fragment.
// Parameters:
// input - buffer to uncompress
// input_size - size of input buffer
// output - uncompressed buffer allocated by caller, should be at least
// max_output_len
// output_size - size of the output buffer
// Returns -1 for errors, remaining input to be processed otherwise.
virtual int Uncompress(const char* input, size_t input_size, char* output,
size_t* output_pos) = 0;
static StreamingUncompress* Create(CompressionType compression_type,
uint32_t compress_format_version,
size_t max_output_len);
virtual void Reset() = 0;
protected:
CompressionType compression_type_;
uint32_t compress_format_version_;
size_t max_output_len_;
};
class ZSTDStreamingCompress final : public StreamingCompress {
public:
explicit ZSTDStreamingCompress(const CompressionOptions& opts,
uint32_t compress_format_version,
size_t max_output_len)
: StreamingCompress(kZSTD, opts, compress_format_version,
max_output_len) {
#ifdef ZSTD_STREAMING
cctx_ = ZSTD_createCCtx();
assert(cctx_ != nullptr);
input_buffer_ = {/*src=*/nullptr, /*size=*/0, /*pos=*/0};
#endif
}
~ZSTDStreamingCompress() override {
#ifdef ZSTD_STREAMING
ZSTD_freeCCtx(cctx_);
#endif
}
int Compress(const char* input, size_t input_size, char* output,
size_t* output_pos) override;
void Reset() override;
#ifdef ZSTD_STREAMING
ZSTD_CCtx* cctx_;
ZSTD_inBuffer input_buffer_;
#endif
};
class ZSTDStreamingUncompress final : public StreamingUncompress {
public:
explicit ZSTDStreamingUncompress(uint32_t compress_format_version,
size_t max_output_len)
: StreamingUncompress(kZSTD, compress_format_version, max_output_len) {
#ifdef ZSTD_STREAMING
dctx_ = ZSTD_createDCtx();
assert(dctx_ != nullptr);
input_buffer_ = {/*src=*/nullptr, /*size=*/0, /*pos=*/0};
#endif
}
~ZSTDStreamingUncompress() override {
#ifdef ZSTD_STREAMING
ZSTD_freeDCtx(dctx_);
#endif
}
int Uncompress(const char* input, size_t input_size, char* output,
size_t* output_size) override;
void Reset() override;
private:
#ifdef ZSTD_STREAMING
ZSTD_DCtx* dctx_;
ZSTD_inBuffer input_buffer_;
#endif
};
} // namespace ROCKSDB_NAMESPACE