Initial implementation of onbufferedamountlow

Source/modules/mediastream/RTCDataChannel.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 58 matching lines @@
 }
 
 RTCDataChannel::RTCDataChannel(ExecutionContext* context, RTCPeerConnection* connection, PassOwnPtr<WebRTCDataChannelHandler> handler)
     : m_executionContext(context)
     , m_handler(handler)
     , m_stopped(false)
     , m_readyState(ReadyStateConnecting)
     , m_binaryType(BinaryTypeArrayBuffer)
     , m_scheduledEventTimer(this, &RTCDataChannel::scheduledEventTimerFired)
     , m_connection(connection)
+    , m_bufferedAmountLowThreshold(0U)
 {
     m_handler->setClient(this);
 }
 
 RTCDataChannel::~RTCDataChannel()
 {
     // If the peer connection and the data channel die in the same
     // GC cycle stop has not been called and we need to notify the
     // client that the channel is gone.
     if (!m_stopped)
@@ skipping 60 matching lines @@
 
     ASSERT_NOT_REACHED();
     return String();
 }
 
 unsigned RTCDataChannel::bufferedAmount() const
 {
     return m_handler->bufferedAmount();
 }
 
+unsigned RTCDataChannel::bufferedAmountLowThreshold() const
+{
+    return m_bufferedAmountLowThreshold;
+}
+
+void RTCDataChannel::setBufferedAmountLowThreshold(unsigned threshold)
+{
+    m_bufferedAmountLowThreshold = threshold;
+}
+
 String RTCDataChannel::binaryType() const
 {
     switch (m_binaryType) {
     case BinaryTypeBlob:
         return "blob";
     case BinaryTypeArrayBuffer:
         return "arraybuffer";
     }
     ASSERT_NOT_REACHED();
     return String();
@@ skipping 74 matching lines @@
         scheduleDispatchEvent(Event::create(EventTypeNames::open));
         break;
     case ReadyStateClosed:
         scheduleDispatchEvent(Event::create(EventTypeNames::close));
         break;
     default:
         break;
     }
 }
 
+void RTCDataChannel::didDecreaseBufferedAmount(unsigned previousAmount)
+{
+    if (previousAmount > m_bufferedAmountLowThreshold
+        && bufferedAmount() <= m_bufferedAmountLowThreshold) {
+        scheduleDispatchEvent(Event::create(EventTypeNames::bufferedamountlow));
+    }
+}
+
 void RTCDataChannel::didReceiveStringData(const WebString& text)
 {
     if (m_stopped)
         return;
 
     scheduleDispatchEvent(MessageEvent::create(text));
 }
 
 void RTCDataChannel::didReceiveRawData(const char* data, size_t dataLength)
 {
@@ skipping 71 matching lines @@
 
 DEFINE_TRACE(RTCDataChannel)
 {
     visitor->trace(m_executionContext);
     visitor->trace(m_scheduledEvents);
     visitor->template registerWeakMembers<RTCDataChannel, &RTCDataChannel::clearWeakMembers>(this);
     RefCountedGarbageCollectedEventTargetWithInlineData<RTCDataChannel>::trace(visitor);
 }
 
 } // namespace blink