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// Copyright 2013 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.
#ifndef NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_
#define NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_
#include <deque>
#include <vector>
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "net/base/net_export.h"
extern "C" struct z_stream_s;
namespace net {
class IOBufferWithSize;
class NET_EXPORT_PRIVATE WebSocketDeflater {
public:
// Do not reorder or remove entries of this enum. The values of them are used
// in UMA.
enum ContextTakeOverMode {
DO_NOT_TAKE_OVER_CONTEXT,
TAKE_OVER_CONTEXT,
NUM_CONTEXT_TAKEOVER_MODE_TYPES,
};
explicit WebSocketDeflater(ContextTakeOverMode mode);
~WebSocketDeflater();
// Returns true if there is no error and false otherwise.
// This function must be called exactly once before calling any of
// following methods.
// |window_bits| must be between 8 and 15 (both inclusive).
bool Initialize(int window_bits);
// Adds bytes to |stream_|.
// Returns true if there is no error and false otherwise.
bool AddBytes(const char* data, size_t size);
// Flushes the current processing data.
// Returns true if there is no error and false otherwise.
bool Finish();
// Pushes "\x00\x00\xff\xff" to the end of the buffer.
void PushSyncMark();
// Returns the current deflated output.
// If the current output is larger than |size| bytes,
// returns the first |size| bytes of the current output.
// The returned bytes will be dropped from the current output and never be
// returned thereafter.
scoped_refptr<IOBufferWithSize> GetOutput(size_t size);
// Returns the size of the current deflated output.
size_t CurrentOutputSize() const { return buffer_.size(); }
private:
void ResetContext();
int Deflate(int flush);
scoped_ptr<z_stream_s> stream_;
ContextTakeOverMode mode_;
std::deque<char> buffer_;
std::vector<char> fixed_buffer_;
// true if bytes were added after last Finish().
bool are_bytes_added_;
DISALLOW_COPY_AND_ASSIGN(WebSocketDeflater);
};
} // namespace net
#endif // NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_