google_apis/gcm/engine/heartbeat_manager.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 GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_
   6 #define GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/logging.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "google_apis/gcm/base/gcm_export.h"
  13
  14 namespace base {
  15 class Timer;
  16 }
  17
  18 namespace mcs_proto {
  19 class HeartbeatConfig;
  20 }
  21
  22 namespace gcm {
  23
  24 // A heartbeat management class, capable of sending and handling heartbeat
  25 // receipt/failures and triggering reconnection as necessary.
  26 class GCM_EXPORT HeartbeatManager {
  27  public:
  28   HeartbeatManager();
  29   ~HeartbeatManager();
  30
  31   // Start the heartbeat logic.
  32   // |send_heartbeat_callback_| is the callback the HeartbeatManager uses to
  33   // send new heartbeats. Only one heartbeat can be outstanding at a time.
  34   void Start(const base::Closure& send_heartbeat_callback,
  35              const base::Closure& trigger_reconnect_callback);
  36
  37   // Stop the timer. Start(..) must be called again to begin sending heartbeats
  38   // afterwards.
  39   void Stop();
  40
  41   // Reset the heartbeat timer. It is valid to call this even if no heartbeat
  42   // is associated with the ack (for example if another signal is used to
  43   // determine that the connection is alive).
  44   void OnHeartbeatAcked();
  45
  46   // Updates the current heartbeat interval.
  47   void UpdateHeartbeatConfig(const mcs_proto::HeartbeatConfig& config);
  48
  49   // Returns the next scheduled heartbeat time. A null time means
  50   // no heartbeat is pending. If non-null and less than the
  51   // current time (in ticks), the heartbeat has been triggered and an ack is
  52   // pending.
  53   base::TimeTicks GetNextHeartbeatTime() const;
  54
  55   // Updates the timer used for scheduling heartbeats.
  56   void UpdateHeartbeatTimer(scoped_ptr<base::Timer> timer);
  57
  58  protected:
  59   // Helper method to send heartbeat on timer trigger.
  60   void OnHeartbeatTriggered();
  61
  62   // Periodic check to see if the heartbeat has been missed due to some system
  63   // issue (e.g. the machine was suspended and the timer did not account for
  64   // that).
  65   void CheckForMissedHeartbeat();
  66
  67  private:
  68   // Restarts the heartbeat timer.
  69   void RestartTimer();
  70
  71   // The base::Time at which the heartbeat timer is expected to fire. Used to
  72   // check if a heartbeat was somehow lost/delayed.
  73   base::Time heartbeat_expected_time_;
  74
  75   // Whether the last heartbeat ping sent has been acknowledged or not.
  76   bool waiting_for_ack_;
  77
  78   // The current heartbeat interval.
  79   int heartbeat_interval_ms_;
  80   // The most recent server-provided heartbeat interval (0 if none has been
  81   // provided).
  82   int server_interval_ms_;
  83
  84   // Timer for triggering heartbeats.
  85   scoped_ptr<base::Timer> heartbeat_timer_;
  86
  87   // Callbacks for interacting with the the connection.
  88   base::Closure send_heartbeat_callback_;
  89   base::Closure trigger_reconnect_callback_;
  90
  91   base::WeakPtrFactory<HeartbeatManager> weak_ptr_factory_;
  92
  93   DISALLOW_COPY_AND_ASSIGN(HeartbeatManager);
  94 };
  95
  96 }  // namespace gcm
  97
  98 #endif  // GOOGLE_APIS_GCM_ENGINE_HEARTBEAT_MANAGER_H_