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 core_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) const;
  65
  66   // Callback for SendKeepAliveMessage.
  67   void SendKeepAliveMessageComplete(const char* message_type, int rv) const;
  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() const;
  72
  73   // Indicates that Start() was called.
  74   bool started_;
  75
  76   // Socket that is managed by the keep-alive object.
  77   CastSocket* socket_;
  78
  79   // Logging object.
  80   scoped_refptr<Logger> logger_;
  81
  82   // Delegate object which receives all non-keep alive messages.
  83   scoped_ptr<CastTransport::Delegate> inner_delegate_;
  84
  85   // Amount of idle time to wait before disconnecting.
  86   base::TimeDelta liveness_timeout_;
  87
  88   // Amount of idle time to wait before pinging the receiver.
  89   base::TimeDelta ping_interval_;
  90
  91   // Fired when |ping_interval_| is exceeded or when triggered by test code.
  92   scoped_ptr<base::Timer> ping_timer_;
  93
  94   // Fired when |liveness_timer_| is exceeded.
  95   scoped_ptr<base::Timer> liveness_timer_;
  96
  97   // The PING message to send over the wire.
  98   CastMessage ping_message_;
  99
 100   // The PONG message to send over the wire.
 101   CastMessage pong_message_;
 102
 103   base::ThreadChecker thread_checker_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(KeepAliveDelegate);
 106 };
 107
 108 }  // namespace cast_channel
 109 }  // namespace core_api
 110 }  // namespace extensions
 111
 112 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_