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 using namespace mozilla::Compression;
  11
  12 namespace {
  13
  14 #include "lz4.c"
  15
  16 }/* anonymous namespace */
  17
  18 /* Our wrappers */
  19
  20 size_t
  21 LZ4::compress(const char* aSource, size_t aInputSize, char* aDest)
  22 {
  23   CheckedInt<int> inputSizeChecked = aInputSize;
  24   MOZ_ASSERT(inputSizeChecked.isValid());
  25   return LZ4_compress(aSource, aDest, inputSizeChecked.value());
  26 }
  27
  28 size_t
  29 LZ4::compressLimitedOutput(const char* aSource, size_t aInputSize, char* aDest,
  30                            size_t aMaxOutputSize)
  31 {
  32   CheckedInt<int> inputSizeChecked = aInputSize;
  33   MOZ_ASSERT(inputSizeChecked.isValid());
  34   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  35   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  36   return LZ4_compress_limitedOutput(aSource, aDest, inputSizeChecked.value(),
  37                                     maxOutputSizeChecked.value());
  38 }
  39
  40 bool
  41 LZ4::decompress(const char* aSource, char* aDest, size_t aOutputSize)
  42 {
  43   CheckedInt<int> outputSizeChecked = aOutputSize;
  44   MOZ_ASSERT(outputSizeChecked.isValid());
  45   int ret = LZ4_decompress_fast(aSource, aDest, outputSizeChecked.value());
  46   return ret >= 0;
  47 }
  48
  49 bool
  50 LZ4::decompress(const char* aSource, size_t aInputSize, char* aDest,
  51                 size_t aMaxOutputSize, size_t* aOutputSize)
  52 {
  53   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  54   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  55   CheckedInt<int> inputSizeChecked = aInputSize;
  56   MOZ_ASSERT(inputSizeChecked.isValid());
  57
  58   int ret = LZ4_decompress_safe(aSource, aDest, inputSizeChecked.value(),
  59                                 maxOutputSizeChecked.value());
  60   if (ret >= 0) {
  61     *aOutputSize = ret;
  62     return true;
  63   }
  64
  65   *aOutputSize = 0;
  66   return false;
  67 }
  68