Process incoming IQs in the same order that they were sent.

remoting/protocol/jingle_session.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_PROTOCOL_JINGLE_SESSION_H_
 #define REMOTING_PROTOCOL_JINGLE_SESSION_H_
 
 #include <list>
 #include <set>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/rand_util.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "crypto/rsa_private_key.h"
 #include "net/base/completion_callback.h"
 #include "remoting/protocol/authenticator.h"
 #include "remoting/protocol/datagram_channel_factory.h"
 #include "remoting/protocol/jingle_messages.h"
 #include "remoting/protocol/session.h"
 #include "remoting/protocol/session_config.h"
 #include "remoting/signaling/iq_sender.h"
@@ skipping 50 matching lines @@
                          const buzz::XmlElement* response);
 
   // Response handler for transport-info responses. Transport-info timeouts are
   // ignored and don't terminate connection.
   void OnTransportInfoResponse(IqRequest* request,
                                const buzz::XmlElement* response);
 
   // Called by JingleSessionManager on incoming |message|. Must call
   // |reply_callback| to send reply message before sending any other
   // messages.
-  void OnIncomingMessage(std::unique_ptr<JingleMessage> message,
+  void OnIncomingMessage(const std::string& id,
+                         std::unique_ptr<JingleMessage> message,
                          const ReplyCallback& reply_callback);
 
+  // Called by OnIncomingMessage() to process the incoming Jingle messages
+  // in the same order that they are sent.
+  void ProcessIncomingMessage(std::unique_ptr<JingleMessage> message,
+                              const ReplyCallback& reply_callback);
+
   // Message handlers for incoming messages.
   void OnAccept(std::unique_ptr<JingleMessage> message,
                 const ReplyCallback& reply_callback);
   void OnSessionInfo(std::unique_ptr<JingleMessage> message,
                      const ReplyCallback& reply_callback);
   void OnTerminate(std::unique_ptr<JingleMessage> message,
                    const ReplyCallback& reply_callback);
 
   // Called from OnAccept() to initialize session config.
   bool InitializeConfigFromDescription(const ContentDescription* description);
 
   // Called after the initial incoming authenticator message is processed.
   void ContinueAcceptIncomingConnection();
 
   // Called after subsequent authenticator messages are processed.
   void ProcessAuthenticationStep();
 
   // Called after the authenticating step is finished.
   void ContinueAuthenticationStep();
 
   // Called when authentication is finished.
   void OnAuthenticated();
 
   // Sets |state_| to |new_state| and calls state change callback.
   void SetState(State new_state);
 
   // Returns true if the state of the session is not CLOSED or FAILED
   bool is_session_active();
 
+  // Returns the value of the ID attribute of the next outgoing set IQ with the
+  // sequence ID encoded.
+  std::string GetNextOutgoingId();
+
   base::ThreadChecker thread_checker_;
 
   JingleSessionManager* session_manager_;
   SignalingAddress peer_address_;
   Session::EventHandler* event_handler_;
 
   std::string session_id_;
   State state_;
   ErrorCode error_;
 
   std::unique_ptr<SessionConfig> config_;
 
   std::unique_ptr<Authenticator> authenticator_;
 
   Transport* transport_ = nullptr;
 
   // Pending Iq requests. Used for all messages except transport-info.
   std::set<std::unique_ptr<IqRequest>> pending_requests_;
 
   // Pending transport-info requests.
   std::list<std::unique_ptr<IqRequest>> transport_info_requests_;
 
+  struct PendingMessage {
+    PendingMessage(std::unique_ptr<JingleMessage> message,
+                   const ReplyCallback& reply_callback);
+    ~PendingMessage();
+    std::unique_ptr<JingleMessage> message;
+    const ReplyCallback reply_callback;
+  };
+
+  // A message queue to guarantee the incoming messages are processed in order.
+  class OrderedMessageQueue;
+  std::unique_ptr<OrderedMessageQueue> message_queue_;
+
+  // This prefix is necessary to disambiguate between the ID's sent from the
+  // client and the ID's sent from the host.
+  std::string outgoing_id_prefix_ = base::Uint64ToString(base::RandUint64());
+  int next_outgoing_id_ = 0;
+
   base::WeakPtrFactory<JingleSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(JingleSession);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_JINGLE_SESSION_H_