google_apis/gcm/engine/connection_handler.h

   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 GOOGLE_APIS_GCM_ENGINE_CONNECTION_HANDLER_H_
   6 #define GOOGLE_APIS_GCM_ENGINE_CONNECTION_HANDLER_H_
   7
   8 #include "base/callback.h"
   9 #include "google_apis/gcm/base/gcm_export.h"
  10
  11 namespace net{
  12 class StreamSocket;
  13 }  // namespace net
  14
  15 namespace google {
  16 namespace protobuf {
  17 class MessageLite;
  18 }  // namespace protobuf
  19 }  // namepsace google
  20
  21 namespace mcs_proto {
  22 class LoginRequest;
  23 }
  24
  25 namespace gcm {
  26
  27 class SocketInputStream;
  28 class SocketOutputStream;
  29
  30 // Handles performing the protocol handshake and sending/receiving protobuf
  31 // messages. Note that no retrying or queueing is enforced at this layer.
  32 // Once a connection error is encountered, the ConnectionHandler will disconnect
  33 // the socket and must be reinitialized with a new StreamSocket before
  34 // messages can be sent/received again.
  35 class GCM_EXPORT ConnectionHandler {
  36  public:
  37   typedef base::Callback<void(scoped_ptr<google::protobuf::MessageLite>)>
  38       ProtoReceivedCallback;
  39   typedef base::Closure ProtoSentCallback;
  40   typedef base::Callback<void(int)> ConnectionChangedCallback;
  41
  42   ConnectionHandler();
  43   virtual ~ConnectionHandler();
  44
  45   // Starts a new MCS connection handshake (using |login_request|) and, upon
  46   // success, begins listening for incoming/outgoing messages.
  47   //
  48   // Note: It is correct and expected to call Init more than once, as connection
  49   // issues are encountered and new connections must be made.
  50   virtual void Init(const mcs_proto::LoginRequest& login_request,
  51                     net::StreamSocket* socket) = 0;
  52
  53   // Resets the handler and any internal state. Should be called any time
  54   // a connection reset happens externally to the handler.
  55   virtual void Reset() = 0;
  56
  57   // Checks that a handshake has been completed and a message is not already
  58   // in flight.
  59   virtual bool CanSendMessage() const = 0;
  60
  61   // Send an MCS protobuf message. CanSendMessage() must be true.
  62   virtual void SendMessage(const google::protobuf::MessageLite& message) = 0;
  63 };
  64
  65 }  // namespace gcm
  66
  67 #endif  // GOOGLE_APIS_GCM_ENGINE_CONNECTION_HANDLER_H_