remoting/protocol/protobuf_message_parser.h

   1 // Copyright 2014 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_PROTOBUF_MESSAGE_PARSER_H_
   6 #define REMOTING_PROTOCOL_PROTOBUF_MESSAGE_PARSER_H_
   7
   8 #include "base/bind.h"
   9 #include "base/callback.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "remoting/base/compound_buffer.h"
  12 #include "remoting/protocol/message_reader.h"
  13
  14 namespace remoting {
  15 namespace protocol {
  16
  17 // Version of MessageReader for protocol buffer messages, that parses
  18 // each incoming message.
  19 template <class T>
  20 class ProtobufMessageParser {
  21  public:
  22   // The callback that is called when a new message is received. |done_task|
  23   // must be called by the callback when it's done processing the |message|.
  24   typedef typename base::Callback<void(scoped_ptr<T> message,
  25                                        const base::Closure& done_task)>
  26       MessageReceivedCallback;
  27
  28   // |message_reader| must outlive ProtobufMessageParser.
  29   ProtobufMessageParser(const MessageReceivedCallback& callback,
  30                         MessageReader* message_reader)
  31       : message_reader_(message_reader),
  32         message_received_callback_(callback) {
  33     message_reader->SetMessageReceivedCallback(base::Bind(
  34         &ProtobufMessageParser<T>::OnNewData, base::Unretained(this)));
  35   }
  36   ~ProtobufMessageParser() {
  37     message_reader_->SetMessageReceivedCallback(
  38         MessageReader::MessageReceivedCallback());
  39   }
  40
  41  private:
  42   void OnNewData(scoped_ptr<CompoundBuffer> buffer,
  43                  const base::Closure& done_task) {
  44     scoped_ptr<T> message(new T());
  45     CompoundBufferInputStream stream(buffer.get());
  46     bool ret = message->ParseFromZeroCopyStream(&stream);
  47     if (!ret) {
  48       LOG(WARNING) << "Received message that is not a valid protocol buffer.";
  49     } else {
  50       DCHECK_EQ(stream.position(), buffer->total_bytes());
  51       message_received_callback_.Run(message.Pass(), done_task);
  52     }
  53   }
  54
  55   MessageReader* message_reader_;
  56   MessageReceivedCallback message_received_callback_;
  57 };
  58
  59 }  // namespace protocol
  60 }  // namespace remoting
  61
  62 #endif  // REMOTING_PROTOCOL_PROTOBUF_MESSAGE_PARSER_H_