1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_ 6 #define NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_ 7 8 #include <deque> 9 #include <vector> 10 11 #include "base/basictypes.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/memory/scoped_ptr.h" 14 #include "net/base/net_export.h" 15 16 extern "C" struct z_stream_s; 17 18 namespace net { 19 20 class IOBufferWithSize; 21 22 class NET_EXPORT_PRIVATE WebSocketDeflater { 23 public: 24 enum ContextTakeOverMode { 25 DO_NOT_TAKE_OVER_CONTEXT, 26 TAKE_OVER_CONTEXT, 27 }; 28 29 explicit WebSocketDeflater(ContextTakeOverMode mode); 30 ~WebSocketDeflater(); 31 32 // Returns true if there is no error and false otherwise. 33 // This function must be called exactly once before calling any of 34 // following methods. 35 // |window_bits| must be between 8 and 15 (both inclusive). 36 bool Initialize(int window_bits); 37 38 // Adds bytes to |stream_|. 39 // Returns true if there is no error and false otherwise. 40 bool AddBytes(const char* data, size_t size); 41 42 // Flushes the current processing data. 43 // Returns true if there is no error and false otherwise. 44 bool Finish(); 45 46 // Pushes "\x00\x00\xff\xff" to the end of the buffer. 47 void PushSyncMark(); 48 49 // Returns the current deflated output. 50 // If the current output is larger than |size| bytes, 51 // returns the first |size| bytes of the current output. 52 // The returned bytes will be dropped from the current output and never be 53 // returned thereafter. 54 scoped_refptr<IOBufferWithSize> GetOutput(size_t size); 55 56 // Returns the size of the current deflated output. CurrentOutputSize()57 size_t CurrentOutputSize() const { return buffer_.size(); } 58 59 private: 60 void ResetContext(); 61 int Deflate(int flush); 62 63 scoped_ptr<z_stream_s> stream_; 64 ContextTakeOverMode mode_; 65 std::deque<char> buffer_; 66 std::vector<char> fixed_buffer_; 67 // true if bytes were added after last Finish(). 68 bool are_bytes_added_; 69 70 DISALLOW_COPY_AND_ASSIGN(WebSocketDeflater); 71 }; 72 73 } // namespace net 74 75 #endif // NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_ 76