remoting/protocol/message_reader.h

   1 // Copyright (c) 2012 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_PROTOCOL_MESSAGE_READER_H_
   6 #define REMOTING_PROTOCOL_MESSAGE_READER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/threading/non_thread_safe.h"
  12 #include "remoting/base/compound_buffer.h"
  13 #include "remoting/protocol/message_decoder.h"
  14
  15 namespace net {
  16 class IOBuffer;
  17 }  // namespace net
  18
  19 namespace remoting {
  20 namespace protocol {
  21
  22 class P2PStreamSocket;
  23
  24 // MessageReader reads data from the socket asynchronously and calls
  25 // callback for each message it receives. It stops calling the
  26 // callback as soon as the socket is closed, so the socket should
  27 // always be closed before the callback handler is destroyed.
  28 //
  29 // In order to throttle the stream, MessageReader doesn't try to read
  30 // new data from the socket until all previously received messages are
  31 // processed by the receiver (|done_task| is called for each message).
  32 // It is still possible that the MessageReceivedCallback is called
  33 // twice (so that there is more than one outstanding message),
  34 // e.g. when we the sender sends multiple messages in one TCP packet.
  35 class MessageReader : public base::NonThreadSafe {
  36  public:
  37   typedef base::Callback<void(scoped_ptr<CompoundBuffer>, const base::Closure&)>
  38       MessageReceivedCallback;
  39   typedef base::Callback<void(int)> ReadFailedCallback;
  40
  41   MessageReader();
  42   virtual ~MessageReader();
  43
  44   // Sets the callback to be called for each incoming message.
  45   void SetMessageReceivedCallback(const MessageReceivedCallback& callback);
  46
  47   // Starts reading from |socket|.
  48   void StartReading(P2PStreamSocket* socket,
  49                     const ReadFailedCallback& read_failed_callback);
  50
  51  private:
  52   void DoRead();
  53   void OnRead(int result);
  54   void HandleReadResult(int result, bool* read_succeeded);
  55   void OnDataReceived(net::IOBuffer* data, int data_size);
  56   void RunCallback(scoped_ptr<CompoundBuffer> message);
  57   void OnMessageDone();
  58
  59   ReadFailedCallback read_failed_callback_;
  60
  61   P2PStreamSocket* socket_;
  62
  63   // Set to true, when we have a socket read pending, and expecting
  64   // OnRead() to be called when new data is received.
  65   bool read_pending_;
  66
  67   // Number of messages that we received, but haven't finished
  68   // processing yet, i.e. |done_task| hasn't been called for these
  69   // messages.
  70   int pending_messages_;
  71
  72   bool closed_;
  73   scoped_refptr<net::IOBuffer> read_buffer_;
  74
  75   MessageDecoder message_decoder_;
  76
  77   // Callback is called when a message is received.
  78   MessageReceivedCallback message_received_callback_;
  79
  80   base::WeakPtrFactory<MessageReader> weak_factory_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(MessageReader);
  83 };
  84
  85 }  // namespace protocol
  86 }  // namespace remoting
  87
  88 #endif  // REMOTING_PROTOCOL_MESSAGE_READER_H_