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rocksdb/util/compression.h

367 lines
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// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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 "rocksdb/options.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
namespace rocksdb {
inline bool Snappy_Compress(const CompressionOptions& opts, 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;
#endif
return false;
}
inline bool Snappy_GetUncompressedLength(const char* input, size_t length,
size_t* result) {
#ifdef SNAPPY
return snappy::GetUncompressedLength(input, length, result);
#else
return false;
#endif
}
inline bool Snappy_Uncompress(const char* input, size_t length,
char* output) {
#ifdef SNAPPY
return snappy::RawUncompress(input, length, output);
#else
return false;
#endif
}
inline bool Zlib_Compress(const CompressionOptions& opts, const char* input,
size_t length, ::std::string* output) {
#ifdef ZLIB
// 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;
z_stream _stream;
memset(&_stream, 0, sizeof(z_stream));
int st = deflateInit2(&_stream, opts.level, Z_DEFLATED, opts.window_bits,
memLevel, opts.strategy);
if (st != Z_OK) {
return false;
}
// Resize output to be the plain data length.
// This may not be big enough if the compression actually expands data.
output->resize(length);
// 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>(length);
_stream.next_out = (Bytef*)&(*output)[0];
size_t old_sz = 0, new_sz = 0, new_sz_delta = 0;
bool done = false;
while (!done) {
st = deflate(&_stream, Z_FINISH);
switch (st) {
case Z_STREAM_END:
done = true;
break;
case Z_OK:
// No output space. Increase the output space by 20%.
// (Should we fail the compression since it expands the size?)
old_sz = output->size();
new_sz_delta = static_cast<size_t>(output->size() * 0.2);
new_sz = output->size() + (new_sz_delta < 10 ? 10 : new_sz_delta);
output->resize(new_sz);
// Set more output.
_stream.next_out = (Bytef *)&(*output)[old_sz];
_stream.avail_out = static_cast<unsigned int>(new_sz - old_sz);
break;
case Z_BUF_ERROR:
default:
deflateEnd(&_stream);
return false;
}
}
output->resize(output->size() - _stream.avail_out);
deflateEnd(&_stream);
return true;
#endif
return false;
}
inline char* Zlib_Uncompress(const char* input_data, size_t input_length,
int* decompress_size, int windowBits = -14) {
#ifdef ZLIB
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;
}
_stream.next_in = (Bytef *)input_data;
_stream.avail_in = static_cast<unsigned int>(input_length);
// Assume the decompressed data size will 5x of compressed size.
size_t output_len = input_length * 5;
char* output = new char[output_len];
size_t old_sz = output_len;
_stream.next_out = (Bytef *)output;
_stream.avail_out = static_cast<unsigned int>(output_len);
char* tmp = nullptr;
size_t output_len_delta;
bool done = false;
//while(_stream.next_in != nullptr && _stream.avail_in != 0) {
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%.
old_sz = output_len;
output_len_delta = static_cast<size_t>(output_len * 0.2);
output_len += output_len_delta < 10 ? 10 : output_len_delta;
tmp = new char[output_len];
memcpy(tmp, output, old_sz);
delete[] output;
output = tmp;
// Set more output.
_stream.next_out = (Bytef *)(output + old_sz);
_stream.avail_out = static_cast<unsigned int>(output_len - old_sz);
break;
case Z_BUF_ERROR:
default:
delete[] output;
inflateEnd(&_stream);
return nullptr;
}
}
*decompress_size = static_cast<int>(output_len - _stream.avail_out);
inflateEnd(&_stream);
return output;
#endif
return nullptr;
}
inline bool BZip2_Compress(const CompressionOptions& opts, const char* input,
size_t length, ::std::string* output) {
#ifdef BZIP2
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;
}
// Resize output to be the plain data length.
// This may not be big enough if the compression actually expands data.
output->resize(length);
// 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.next_out = (char *)&(*output)[0];
_stream.avail_out = static_cast<unsigned int>(length);
size_t old_sz = 0, new_sz = 0;
while (_stream.next_in != nullptr && _stream.avail_in != 0) {
st = BZ2_bzCompress(&_stream, BZ_FINISH);
switch (st) {
case BZ_STREAM_END:
break;
case BZ_FINISH_OK:
// No output space. Increase the output space by 20%.
// (Should we fail the compression since it expands the size?)
old_sz = output->size();
new_sz = static_cast<size_t>(output->size() * 1.2);
output->resize(new_sz);
// Set more output.
_stream.next_out = (char *)&(*output)[old_sz];
_stream.avail_out = static_cast<unsigned int>(new_sz - old_sz);
break;
case BZ_SEQUENCE_ERROR:
default:
BZ2_bzCompressEnd(&_stream);
return false;
}
}
output->resize(output->size() - _stream.avail_out);
BZ2_bzCompressEnd(&_stream);
return true;
#endif
return false;
}
inline char* BZip2_Uncompress(const char* input_data, size_t input_length,
int* decompress_size) {
#ifdef BZIP2
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);
// Assume the decompressed data size will be 5x of compressed size.
size_t output_len = input_length * 5;
char* output = new char[output_len];
size_t old_sz = output_len;
_stream.next_out = (char *)output;
_stream.avail_out = static_cast<unsigned int>(output_len);
char* tmp = nullptr;
while(_stream.next_in != nullptr && _stream.avail_in != 0) {
st = BZ2_bzDecompress(&_stream);
switch (st) {
case BZ_STREAM_END:
break;
case BZ_OK:
// No output space. Increase the output space by 20%.
old_sz = output_len;
output_len = static_cast<size_t>(output_len * 1.2);
tmp = new char[output_len];
memcpy(tmp, output, old_sz);
delete[] output;
output = tmp;
// Set more output.
_stream.next_out = (char *)(output + old_sz);
_stream.avail_out = static_cast<unsigned int>(output_len - old_sz);
break;
default:
delete[] output;
BZ2_bzDecompressEnd(&_stream);
return nullptr;
}
}
*decompress_size = static_cast<int>(output_len - _stream.avail_out);
BZ2_bzDecompressEnd(&_stream);
return output;
#endif
return nullptr;
}
inline bool LZ4_Compress(const CompressionOptions &opts, const char *input,
size_t length, ::std::string* output) {
#ifdef LZ4
int compressBound = LZ4_compressBound(static_cast<int>(length));
output->resize(static_cast<size_t>(8 + compressBound));
char* p = const_cast<char*>(output->c_str());
memcpy(p, &length, sizeof(length));
int outlen = LZ4_compress_limitedOutput(
input, p + 8, static_cast<int>(length), compressBound);
if (outlen == 0) {
return false;
}
output->resize(static_cast<size_t>(8 + outlen));
return true;
#endif
return false;
}
inline char* LZ4_Uncompress(const char* input_data, size_t input_length,
int* decompress_size) {
#ifdef LZ4
if (input_length < 8) {
return nullptr;
}
int output_len;
memcpy(&output_len, input_data, sizeof(output_len));
char *output = new char[output_len];
*decompress_size = LZ4_decompress_safe_partial(
input_data + 8, output, static_cast<int>(input_length - 8), output_len,
output_len);
if (*decompress_size < 0) {
delete[] output;
return nullptr;
}
return output;
#endif
return nullptr;
}
inline bool LZ4HC_Compress(const CompressionOptions &opts, const char* input,
size_t length, ::std::string* output) {
#ifdef LZ4
int compressBound = LZ4_compressBound(static_cast<int>(length));
output->resize(static_cast<size_t>(8 + compressBound));
char* p = const_cast<char*>(output->c_str());
memcpy(p, &length, sizeof(length));
int outlen;
#ifdef LZ4_VERSION_MAJOR // they only started defining this since r113
outlen = LZ4_compressHC2_limitedOutput(input, p + 8, static_cast<int>(length),
compressBound, opts.level);
#else
outlen = LZ4_compressHC_limitedOutput(input, p + 8, static_cast<int>(length),
compressBound);
#endif
if (outlen == 0) {
return false;
}
output->resize(static_cast<size_t>(8 + outlen));
return true;
#endif
return false;
}
} // namespace rocksdb