mfbt/Compression.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/Compression.h"
   8 #include "mozilla/CheckedInt.h"
   9
  10 // Without including <string>, MSVC 2015 complains about e.g. the impossibility
  11 // to convert `const void* const` to `void*` when calling memchr from
  12 // corecrt_memory.h.
  13 #include <string>
  14
  15 #include "lz4.h"
  16
  17 using namespace mozilla::Compression;
  18
  19 /* Our wrappers */
  20
  21 size_t LZ4::compress(const char* aSource, size_t aInputSize, char* aDest) {
  22   CheckedInt<int> inputSizeChecked = aInputSize;
  23   MOZ_ASSERT(inputSizeChecked.isValid());
  24   return LZ4_compress_default(aSource, aDest, inputSizeChecked.value(),
  25                               LZ4_compressBound(inputSizeChecked.value()));
  26 }
  27
  28 size_t LZ4::compressLimitedOutput(const char* aSource, size_t aInputSize,
  29                                   char* aDest, size_t aMaxOutputSize) {
  30   CheckedInt<int> inputSizeChecked = aInputSize;
  31   MOZ_ASSERT(inputSizeChecked.isValid());
  32   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  33   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  34   return LZ4_compress_default(aSource, aDest, inputSizeChecked.value(),
  35                               maxOutputSizeChecked.value());
  36 }
  37
  38 bool LZ4::decompress(const char* aSource, char* aDest, size_t aOutputSize) {
  39   CheckedInt<int> outputSizeChecked = aOutputSize;
  40   MOZ_ASSERT(outputSizeChecked.isValid());
  41   int ret = LZ4_decompress_fast(aSource, aDest, outputSizeChecked.value());
  42   return ret >= 0;
  43 }
  44
  45 bool LZ4::decompress(const char* aSource, size_t aInputSize, char* aDest,
  46                      size_t aMaxOutputSize, size_t* aOutputSize) {
  47   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  48   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  49   CheckedInt<int> inputSizeChecked = aInputSize;
  50   MOZ_ASSERT(inputSizeChecked.isValid());
  51
  52   int ret = LZ4_decompress_safe(aSource, aDest, inputSizeChecked.value(),
  53                                 maxOutputSizeChecked.value());
  54   if (ret >= 0) {
  55     *aOutputSize = ret;
  56     return true;
  57   }
  58
  59   *aOutputSize = 0;
  60   return false;
  61 }
  62
  63 bool LZ4::decompressPartial(const char* aSource, size_t aInputSize, char* aDest,
  64                             size_t aMaxOutputSize, size_t* aOutputSize) {
  65   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  66   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  67   CheckedInt<int> inputSizeChecked = aInputSize;
  68   MOZ_ASSERT(inputSizeChecked.isValid());
  69
  70   int ret = LZ4_decompress_safe_partial(
  71       aSource, aDest, inputSizeChecked.value(), maxOutputSizeChecked.value(),
  72       maxOutputSizeChecked.value());
  73   if (ret >= 0) {
  74     *aOutputSize = ret;
  75     return true;
  76   }
  77
  78   *aOutputSize = 0;
  79   return false;
  80 }