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      1 /*
      2  * Copyright (C) 2010 Julien Chaffraix <jchaffraix (at) webkit.org>
      3  * All right reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     15  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     16  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     17  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     18  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     19  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     20  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #ifndef XMLHttpRequestProgressEventThrottle_h
     28 #define XMLHttpRequestProgressEventThrottle_h
     29 
     30 #include "platform/Timer.h"
     31 #include "platform/heap/Handle.h"
     32 #include "wtf/PassRefPtr.h"
     33 #include "wtf/Vector.h"
     34 #include "wtf/text/AtomicString.h"
     35 
     36 namespace WebCore {
     37 
     38 class Event;
     39 class EventTarget;
     40 
     41 enum ProgressEventAction {
     42     DoNotFlushProgressEvent,
     43     FlushDeferredProgressEvent,
     44     FlushProgressEvent
     45 };
     46 
     47 // This implements the XHR2 progress event dispatching: "dispatch a progress event called progress
     48 // about every 50ms or for every byte received, whichever is least frequent".
     49 class XMLHttpRequestProgressEventThrottle FINAL : public TimerBase {
     50     DISALLOW_ALLOCATION();
     51 public:
     52     explicit XMLHttpRequestProgressEventThrottle(EventTarget*);
     53     virtual ~XMLHttpRequestProgressEventThrottle();
     54 
     55     // Dispatches a ProgressEvent.
     56     //
     57     // Special treatment for events named "progress" is implemented to dispatch
     58     // them at the required frequency. If this object is suspended, the given
     59     // ProgressEvent overwrites the existing. I.e. only the latest one gets
     60     // queued. If the timer is running, this method just updates
     61     // m_lengthComputable, m_loaded and m_total. They'll be used on next
     62     // fired() call.
     63     void dispatchProgressEvent(const AtomicString&, bool lengthComputable, unsigned long long loaded, unsigned long long total);
     64     void dispatchReadyStateChangeEvent(PassRefPtrWillBeRawPtr<Event>, ProgressEventAction = DoNotFlushProgressEvent);
     65 
     66     void suspend();
     67     void resume();
     68 
     69     void trace(Visitor*);
     70 
     71 private:
     72     static const double minimumProgressEventDispatchingIntervalInSeconds;
     73 
     74     // Dispatches an event. If suspended, just queues the given event.
     75     void dispatchEvent(PassRefPtrWillBeRawPtr<Event>);
     76 
     77     virtual void fired() OVERRIDE;
     78     void dispatchDeferredEvents(Timer<XMLHttpRequestProgressEventThrottle>*);
     79     bool flushDeferredProgressEvent();
     80     void deliverProgressEvent();
     81 
     82     bool hasEventToDispatch() const;
     83 
     84     // Non-Oilpan, keep a weak pointer to our XMLHttpRequest object as it is
     85     // the one holding us. With Oilpan, a simple strong Member can be used -
     86     // this XMLHttpRequestProgressEventThrottle (part) object dies together
     87     // with the XMLHttpRequest object.
     88     RawPtrWillBeMember<EventTarget> m_target;
     89 
     90     bool m_lengthComputable;
     91     unsigned long long m_loaded;
     92     unsigned long long m_total;
     93 
     94     bool m_deferEvents;
     95     RefPtrWillBeMember<Event> m_deferredProgressEvent;
     96     WillBeHeapVector<RefPtrWillBeMember<Event> > m_deferredEvents;
     97     Timer<XMLHttpRequestProgressEventThrottle> m_dispatchDeferredEventsTimer;
     98 };
     99 
    100 } // namespace WebCore
    101 
    102 #endif // XMLHttpRequestProgressEventThrottle_h
    103