remoting/base/decompressor_zlib.cc

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "remoting/base/decompressor_zlib.h"

#if defined(USE_SYSTEM_ZLIB)
#include <zlib.h>
#else
#include "third_party/zlib/zlib.h"
#endif
#include "base/logging.h"

namespace remoting {

DecompressorZlib::DecompressorZlib() {
  InitStream();
}

DecompressorZlib::~DecompressorZlib() {
  inflateEnd(stream_.get());
}

void DecompressorZlib::Reset() {
  inflateEnd(stream_.get());
  InitStream();
}

bool DecompressorZlib::Process(const uint8* input_data, int input_size,
                               uint8* output_data, int output_size,
                               int* consumed, int* written) {
  DCHECK_GT(output_size, 0);

  // Setup I/O parameters.
  stream_->avail_in = input_size;
  stream_->next_in = (Bytef*)input_data;
  stream_->avail_out = output_size;
  stream_->next_out = (Bytef*)output_data;

  int ret = inflate(stream_.get(), Z_NO_FLUSH);
  if (ret == Z_STREAM_ERROR) {
    NOTREACHED() << "zlib compression failed";
  }

  *consumed = input_size - stream_->avail_in;
  *written = output_size - stream_->avail_out;

  // Since we check that output is always greater than 0, the only
  // reason for us to get Z_BUF_ERROR is when zlib requires more input
  // data.
  return ret == Z_OK || ret == Z_BUF_ERROR;
}

void DecompressorZlib::InitStream() {
  stream_.reset(new z_stream());

  stream_->next_in = Z_NULL;
  stream_->zalloc = Z_NULL;
  stream_->zfree = Z_NULL;
  stream_->opaque = Z_NULL;

  int ret = inflateInit(stream_.get());
  DCHECK_EQ(ret, Z_OK);
}

}  // namespace remoting