extensions/browser/api/cast_channel/keep_alive_delegate.h

   1 // Copyright 2015 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 EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
   6 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
   7
   8 #include "base/threading/thread_checker.h"
   9 #include "base/timer/timer.h"
  10 #include "extensions/browser/api/cast_channel/cast_transport.h"
  11 #include "extensions/common/api/cast_channel/cast_channel.pb.h"
  12
  13 namespace extensions {
  14 namespace api {
  15 namespace cast_channel {
  16
  17 class CastSocket;
  18 class Logger;
  19
  20 // Decorator delegate which provides keep-alive functionality.
  21 // Keep-alive messages are handled by this object; all other messages and
  22 // errors are passed to |inner_delegate_|.
  23 class KeepAliveDelegate : public CastTransport::Delegate {
  24  public:
  25   // |socket|: The socket to be kept alive.
  26   // |logger|: The logging object which collects protocol events and error
  27   //           details.
  28   // |inner_delegate|: The delegate which processes all non-keep-alive
  29   //                   messages. This object assumes ownership of
  30   //                   |inner_delegate|.
  31   // |ping_interval|: The amount of idle time to wait before sending a PING to
  32   //                  the remote end.
  33   // |liveness_timeout|: The amount of idle time to wait before terminating the
  34   //                     connection.
  35   KeepAliveDelegate(CastSocket* socket,
  36                     scoped_refptr<Logger> logger,
  37                     scoped_ptr<CastTransport::Delegate> inner_delegate,
  38                     base::TimeDelta ping_interval,
  39                     base::TimeDelta liveness_timeout);
  40
  41   ~KeepAliveDelegate() override;
  42
  43   // Creates a keep-alive message (e.g. PING or PONG).
  44   static CastMessage CreateKeepAliveMessage(const char* message_type);
  45
  46   void SetTimersForTest(scoped_ptr<base::Timer> injected_ping_timer,
  47                         scoped_ptr<base::Timer> injected_liveness_timer);
  48
  49   // CastTransport::Delegate implementation.
  50   void Start() override;
  51   void OnError(ChannelError error_state) override;
  52   void OnMessage(const CastMessage& message) override;
  53
  54   static const char kHeartbeatPingType[];
  55   static const char kHeartbeatPongType[];
  56
  57  private:
  58   // Restarts the ping/liveness timeout timers. Called when a message
  59   // is received from the remote end.
  60   void ResetTimers();
  61
  62   // Sends a formatted PING or PONG message to the remote side.
  63   void SendKeepAliveMessage(const CastMessage& message,
  64                             const char* message_type);
  65
  66   // Callback for SendKeepAliveMessage.
  67   void SendKeepAliveMessageComplete(const char* message_type, int rv);
  68
  69   // Called when the liveness timer expires, indicating that the remote
  70   // end has not responded within the |liveness_timeout_| interval.
  71   void LivenessTimeout();
  72
  73   // Stops the ping and liveness timers if they are started.
  74   // To be called after an error.
  75   void Stop();
  76
  77   // Indicates that Start() was called.
  78   bool started_;
  79
  80   // Socket that is managed by the keep-alive object.
  81   CastSocket* socket_;
  82
  83   // Logging object.
  84   scoped_refptr<Logger> logger_;
  85
  86   // Delegate object which receives all non-keep alive messages.
  87   scoped_ptr<CastTransport::Delegate> inner_delegate_;
  88
  89   // Amount of idle time to wait before disconnecting.
  90   base::TimeDelta liveness_timeout_;
  91
  92   // Amount of idle time to wait before pinging the receiver.
  93   base::TimeDelta ping_interval_;
  94
  95   // Fired when |ping_interval_| is exceeded or when triggered by test code.
  96   scoped_ptr<base::Timer> ping_timer_;
  97
  98   // Fired when |liveness_timer_| is exceeded.
  99   scoped_ptr<base::Timer> liveness_timer_;
 100
 101   // The PING message to send over the wire.
 102   CastMessage ping_message_;
 103
 104   // The PONG message to send over the wire.
 105   CastMessage pong_message_;
 106
 107   base::ThreadChecker thread_checker_;
 108
 109   DISALLOW_COPY_AND_ASSIGN(KeepAliveDelegate);
 110 };
 111
 112 }  // namespace cast_channel
 113 }  // namespace api
 114 }  // namespace extensions
 115
 116 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_