gecko-dev/mfbt/Compression.cpp

83 строки
2.6 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Compression.h"
#include "mozilla/CheckedInt.h"
// Without including <string>, MSVC 2015 complains about e.g. the impossibility
// to convert `const void* const` to `void*` when calling memchr from
// corecrt_memory.h.
#include <string>
// Because we wrap lz4.c in an anonymous namespace, all of its #includes
// go in the anonymous namespace too. This would create conflicting
// declarations for intrinsic functions that are internally defined
// at top-level. Including intrin.h here prevents it from being included
// later within the anonymous namespace.
#ifdef _MSC_VER
#include <intrin.h>
#endif
using namespace mozilla::Compression;
namespace {
#include "lz4.c"
}/* anonymous namespace */
/* Our wrappers */
size_t
LZ4::compress(const char* aSource, size_t aInputSize, char* aDest)
{
CheckedInt<int> inputSizeChecked = aInputSize;
MOZ_ASSERT(inputSizeChecked.isValid());
return LZ4_compress(aSource, aDest, inputSizeChecked.value());
}
size_t
LZ4::compressLimitedOutput(const char* aSource, size_t aInputSize, char* aDest,
size_t aMaxOutputSize)
{
CheckedInt<int> inputSizeChecked = aInputSize;
MOZ_ASSERT(inputSizeChecked.isValid());
CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
MOZ_ASSERT(maxOutputSizeChecked.isValid());
return LZ4_compress_limitedOutput(aSource, aDest, inputSizeChecked.value(),
maxOutputSizeChecked.value());
}
bool
LZ4::decompress(const char* aSource, char* aDest, size_t aOutputSize)
{
CheckedInt<int> outputSizeChecked = aOutputSize;
MOZ_ASSERT(outputSizeChecked.isValid());
int ret = LZ4_decompress_fast(aSource, aDest, outputSizeChecked.value());
return ret >= 0;
}
bool
LZ4::decompress(const char* aSource, size_t aInputSize, char* aDest,
size_t aMaxOutputSize, size_t* aOutputSize)
{
CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
MOZ_ASSERT(maxOutputSizeChecked.isValid());
CheckedInt<int> inputSizeChecked = aInputSize;
MOZ_ASSERT(inputSizeChecked.isValid());
int ret = LZ4_decompress_safe(aSource, aDest, inputSizeChecked.value(),
maxOutputSizeChecked.value());
if (ret >= 0) {
*aOutputSize = ret;
return true;
}
*aOutputSize = 0;
return false;
}