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 // Do not reorder or remove entries of this enum. The values of them are used 25 // in UMA. 26 enum ContextTakeOverMode { 27 DO_NOT_TAKE_OVER_CONTEXT, 28 TAKE_OVER_CONTEXT, 29 NUM_CONTEXT_TAKEOVER_MODE_TYPES, 30 }; 31 32 explicit WebSocketDeflater(ContextTakeOverMode mode); 33 ~WebSocketDeflater(); 34 35 // Returns true if there is no error and false otherwise. 36 // This function must be called exactly once before calling any of 37 // following methods. 38 // |window_bits| must be between 8 and 15 (both inclusive). 39 bool Initialize(int window_bits); 40 41 // Adds bytes to |stream_|. 42 // Returns true if there is no error and false otherwise. 43 bool AddBytes(const char* data, size_t size); 44 45 // Flushes the current processing data. 46 // Returns true if there is no error and false otherwise. 47 bool Finish(); 48 49 // Pushes "\x00\x00\xff\xff" to the end of the buffer. 50 void PushSyncMark(); 51 52 // Returns the current deflated output. 53 // If the current output is larger than |size| bytes, 54 // returns the first |size| bytes of the current output. 55 // The returned bytes will be dropped from the current output and never be 56 // returned thereafter. 57 scoped_refptr<IOBufferWithSize> GetOutput(size_t size); 58 59 // Returns the size of the current deflated output. CurrentOutputSize()60 size_t CurrentOutputSize() const { return buffer_.size(); } 61 62 private: 63 void ResetContext(); 64 int Deflate(int flush); 65 66 scoped_ptr<z_stream_s> stream_; 67 ContextTakeOverMode mode_; 68 std::deque<char> buffer_; 69 std::vector<char> fixed_buffer_; 70 // true if bytes were added after last Finish(). 71 bool are_bytes_added_; 72 73 DISALLOW_COPY_AND_ASSIGN(WebSocketDeflater); 74 }; 75 76 } // namespace net 77 78 #endif // NET_WEBSOCKETS_WEBSOCKET_DEFLATER_H_ 79