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// Copyright (c) 2010 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/compressor_zlib.h"
#if defined(USE_SYSTEM_ZLIB)
#include <zlib.h>
#else
#include "third_party/zlib/zlib.h"
#endif
#include "base/logging.h"
namespace remoting {
CompressorZlib::CompressorZlib() {
Reset();
}
CompressorZlib::~CompressorZlib() {
deflateEnd(stream_.get());
}
void CompressorZlib::Reset() {
if (stream_.get())
deflateEnd(stream_.get());
stream_.reset(new z_stream());
stream_->next_in = Z_NULL;
stream_->zalloc = Z_NULL;
stream_->zfree = Z_NULL;
stream_->opaque = Z_NULL;
deflateInit(stream_.get(), Z_BEST_SPEED);
}
bool CompressorZlib::Process(const uint8* input_data, int input_size,
uint8* output_data, int output_size,
CompressorFlush flush, 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 z_flush = 0;
if (flush == CompressorSyncFlush) {
z_flush = Z_SYNC_FLUSH;
} else if (flush == CompressorFinish) {
z_flush = Z_FINISH;
} else if (flush == CompressorNoFlush) {
z_flush = Z_NO_FLUSH;
} else {
NOTREACHED() << "Unsupported flush mode";
}
int ret = deflate(stream_.get(), z_flush);
if (ret == Z_STREAM_ERROR) {
NOTREACHED() << "zlib compression failed";
}
*consumed = input_size - stream_->avail_in;
*written = output_size - stream_->avail_out;
// If |ret| equals Z_STREAM_END we have reached the end of stream.
// If |ret| equals Z_BUF_ERROR we have the end of the synchronication point.
// For these two cases we need to stop compressing.
if (ret == Z_OK) {
return true;
} else if (ret == Z_STREAM_END) {
return false;
} else if (ret == Z_BUF_ERROR) {
return stream_->avail_out == 0;
} else {
NOTREACHED() << "Unexpected zlib error: " << ret;
return false;
}
}
} // namespace remoting
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