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
  22 LZ4::compress(const char* aSource, size_t aInputSize, char* aDest)
  23 {
  24   CheckedInt<int> inputSizeChecked = aInputSize;
  25   MOZ_ASSERT(inputSizeChecked.isValid());
  26   return LZ4_compress_default(aSource, aDest, inputSizeChecked.value(),
  27                               LZ4_compressBound(inputSizeChecked.value()));
  28 }
  29
  30 size_t
  31 LZ4::compressLimitedOutput(const char* aSource, size_t aInputSize, char* aDest,
  32                            size_t aMaxOutputSize)
  33 {
  34   CheckedInt<int> inputSizeChecked = aInputSize;
  35   MOZ_ASSERT(inputSizeChecked.isValid());
  36   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  37   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  38   return LZ4_compress_default(aSource, aDest, inputSizeChecked.value(),
  39                               maxOutputSizeChecked.value());
  40 }
  41
  42 bool
  43 LZ4::decompress(const char* aSource, char* aDest, size_t aOutputSize)
  44 {
  45   CheckedInt<int> outputSizeChecked = aOutputSize;
  46   MOZ_ASSERT(outputSizeChecked.isValid());
  47   int ret = LZ4_decompress_fast(aSource, aDest, outputSizeChecked.value());
  48   return ret >= 0;
  49 }
  50
  51 bool
  52 LZ4::decompress(const char* aSource, size_t aInputSize, char* aDest,
  53                 size_t aMaxOutputSize, size_t* aOutputSize)
  54 {
  55   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  56   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  57   CheckedInt<int> inputSizeChecked = aInputSize;
  58   MOZ_ASSERT(inputSizeChecked.isValid());
  59
  60   int ret = LZ4_decompress_safe(aSource, aDest, inputSizeChecked.value(),
  61                                 maxOutputSizeChecked.value());
  62   if (ret >= 0) {
  63     *aOutputSize = ret;
  64     return true;
  65   }
  66
  67   *aOutputSize = 0;
  68   return false;
  69 }
  70
  71 bool
  72 LZ4::decompressPartial(const char* aSource, size_t aInputSize, char* aDest,
  73                        size_t aMaxOutputSize, size_t* aOutputSize)
  74 {
  75   CheckedInt<int> maxOutputSizeChecked = aMaxOutputSize;
  76   MOZ_ASSERT(maxOutputSizeChecked.isValid());
  77   CheckedInt<int> inputSizeChecked = aInputSize;
  78   MOZ_ASSERT(inputSizeChecked.isValid());
  79
  80   int ret = LZ4_decompress_safe_partial(aSource, aDest,
  81                                         inputSizeChecked.value(),
  82                                         maxOutputSizeChecked.value(),
  83                                         maxOutputSizeChecked.value());
  84   if (ret >= 0) {
  85     *aOutputSize = ret;
  86     return true;
  87   }
  88
  89   *aOutputSize = 0;
  90   return false;
  91 }