rocksdb/port/win/xpress_win.cc

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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.
#include "port/win/xpress_win.h"
#include <windows.h>
#include <cassert>
#include <memory>
#include <limits>
#include <iostream>
#ifdef XPRESS
// Put this under ifdef so windows systems w/o this
// can still build
#include <compressapi.h>
namespace ROCKSDB_NAMESPACE {
namespace port {
namespace xpress {
// Helpers
namespace {
auto CloseCompressorFun = [](void* h) {
if (NULL != h) {
::CloseCompressor(reinterpret_cast<COMPRESSOR_HANDLE>(h));
}
};
auto CloseDecompressorFun = [](void* h) {
if (NULL != h) {
::CloseDecompressor(reinterpret_cast<DECOMPRESSOR_HANDLE>(h));
}
};
}
bool Compress(const char* input, size_t length, std::string* output) {
assert(input != nullptr);
assert(output != nullptr);
if (length == 0) {
output->clear();
return true;
}
COMPRESS_ALLOCATION_ROUTINES* allocRoutinesPtr = nullptr;
COMPRESSOR_HANDLE compressor = NULL;
BOOL success = CreateCompressor(
COMPRESS_ALGORITHM_XPRESS, // Compression Algorithm
allocRoutinesPtr, // Optional allocation routine
&compressor); // Handle
if (!success) {
#ifdef _DEBUG
std::cerr << "XPRESS: Failed to create Compressor LastError: " <<
GetLastError() << std::endl;
#endif
return false;
}
std::unique_ptr<void, decltype(CloseCompressorFun)>
compressorGuard(compressor, CloseCompressorFun);
SIZE_T compressedBufferSize = 0;
// Query compressed buffer size.
success = ::Compress(
compressor, // Compressor Handle
const_cast<char*>(input), // Input buffer
length, // Uncompressed data size
NULL, // Compressed Buffer
0, // Compressed Buffer size
&compressedBufferSize); // Compressed Data size
if (!success) {
auto lastError = GetLastError();
if (lastError != ERROR_INSUFFICIENT_BUFFER) {
#ifdef _DEBUG
std::cerr <<
"XPRESS: Failed to estimate compressed buffer size LastError " <<
lastError << std::endl;
#endif
return false;
}
}
assert(compressedBufferSize > 0);
std::string result;
result.resize(compressedBufferSize);
SIZE_T compressedDataSize = 0;
// Compress
success = ::Compress(
compressor, // Compressor Handle
const_cast<char*>(input), // Input buffer
length, // Uncompressed data size
&result[0], // Compressed Buffer
compressedBufferSize, // Compressed Buffer size
&compressedDataSize); // Compressed Data size
if (!success) {
#ifdef _DEBUG
std::cerr << "XPRESS: Failed to compress LastError " <<
GetLastError() << std::endl;
#endif
return false;
}
result.resize(compressedDataSize);
output->swap(result);
return true;
}
char* Decompress(const char* input_data, size_t input_length,
int* decompress_size) {
assert(input_data != nullptr);
assert(decompress_size != nullptr);
if (input_length == 0) {
return nullptr;
}
COMPRESS_ALLOCATION_ROUTINES* allocRoutinesPtr = nullptr;
DECOMPRESSOR_HANDLE decompressor = NULL;
BOOL success = CreateDecompressor(
COMPRESS_ALGORITHM_XPRESS, // Compression Algorithm
allocRoutinesPtr, // Optional allocation routine
&decompressor); // Handle
if (!success) {
#ifdef _DEBUG
std::cerr << "XPRESS: Failed to create Decompressor LastError "
<< GetLastError() << std::endl;
#endif
return nullptr;
}
std::unique_ptr<void, decltype(CloseDecompressorFun)>
compressorGuard(decompressor, CloseDecompressorFun);
SIZE_T decompressedBufferSize = 0;
success = ::Decompress(
decompressor, // Compressor Handle
const_cast<char*>(input_data), // Compressed data
input_length, // Compressed data size
NULL, // Buffer set to NULL
0, // Buffer size set to 0
&decompressedBufferSize); // Decompressed Data size
if (!success) {
auto lastError = GetLastError();
if (lastError != ERROR_INSUFFICIENT_BUFFER) {
#ifdef _DEBUG
std::cerr
<< "XPRESS: Failed to estimate decompressed buffer size LastError "
<< lastError << std::endl;
#endif
return nullptr;
}
}
assert(decompressedBufferSize > 0);
// On Windows we are limited to a 32-bit int for the
// output data size argument
// so we hopefully never get here
if (decompressedBufferSize > std::numeric_limits<int>::max()) {
assert(false);
return nullptr;
}
// The callers are deallocating using delete[]
// thus we must allocate with new[]
std::unique_ptr<char[]> outputBuffer(new char[decompressedBufferSize]);
SIZE_T decompressedDataSize = 0;
success = ::Decompress(
decompressor,
const_cast<char*>(input_data),
input_length,
outputBuffer.get(),
decompressedBufferSize,
&decompressedDataSize);
if (!success) {
#ifdef _DEBUG
std::cerr <<
"XPRESS: Failed to decompress LastError " <<
GetLastError() << std::endl;
#endif
return nullptr;
}
*decompress_size = static_cast<int>(decompressedDataSize);
// Return the raw buffer to the caller supporting the tradition
return outputBuffer.release();
}
}
}
} // namespace ROCKSDB_NAMESPACE
#endif