remoting/base/protocol_decoder.h

   1 // Copyright (c) 2010 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 REMOTING_BASE_PROTOCOL_DECODER_H_
   6 #define REMOTING_BASE_PROTOCOL_DECODER_H_
   7
   8 #include <deque>
   9 #include <vector>
  10
  11 #include "base/ref_counted.h"
  12 #include "google/protobuf/message_lite.h"
  13 #include "media/base/data_buffer.h"
  14 #include "remoting/base/protocol/chromotocol.pb.h"
  15
  16 namespace remoting {
  17
  18 typedef std::vector<HostMessage*> HostMessageList;
  19 typedef std::vector<ClientMessage*> ClientMessageList;
  20
  21 // A protocol decoder is used to decode data transmitted in the chromoting
  22 // network.
  23 // TODO(hclam): Defines the interface and implement methods.
  24 class ProtocolDecoder {
  25  public:
  26   ProtocolDecoder();
  27
  28   virtual ~ProtocolDecoder() {}
  29
  30   // Parse data received from network into ClientMessages. Ownership of |data|
  31   // is passed to this object and output is written to |messages|.
  32   virtual void ParseClientMessages(scoped_refptr<media::DataBuffer> data,
  33                                    ClientMessageList* messages);
  34
  35   // Parse data received from network into HostMessages. Ownership of |data|
  36   // is passed to this object and output is written to |messages|.
  37   virtual void ParseHostMessages(scoped_refptr<media::DataBuffer> data,
  38                                  HostMessageList* messages);
  39
  40  private:
  41   // A private method used to parse data received from network into protocol
  42   // buffers.
  43   template <typename T>
  44   void ParseMessages(scoped_refptr<media::DataBuffer> data,
  45                      std::vector<T*>* messages);
  46
  47   // Parse one message from |data_list_|. Return true if sucessful.
  48   template <typename T>
  49   bool ParseOneMessage(T** messages);
  50
  51   // A utility method to read payload size of the protocol buffer from the
  52   // data list. Return false if we don't have enough data.
  53   bool GetPayloadSize(int* size);
  54
  55   typedef std::deque<scoped_refptr<media::DataBuffer> > DataList;
  56   DataList data_list_;
  57   size_t last_read_position_;
  58
  59   // Count the number of bytes in |data_list_| not read.
  60   size_t available_bytes_;
  61
  62   // Stores the size of the next payload if known.
  63   size_t next_payload_;
  64
  65   // True if the size of the next payload is known. After one payload is read,
  66   // this is reset to false.
  67   bool next_payload_known_;
  68 };
  69
  70 }  // namespace remoting
  71
  72 #endif  // REMOTING_BASE_PROTOCOL_DECODER_H_