1/* 2 * Copyright (C) 2010 Julien Chaffraix <jchaffraix@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/OwnPtr.h" 33#include "wtf/PassRefPtr.h" 34#include "wtf/Vector.h" 35#include "wtf/text/AtomicString.h" 36 37namespace blink { 38 39class Event; 40class EventTarget; 41class XMLHttpRequestProgressEvent; 42 43// This class implements the XHR2 ProgressEvent dispatching: 44// "dispatch a progress event named progress about every 50ms or for every 45// byte received, whichever is least frequent". 46// 47// readystatechange events also go through this class since ProgressEvents and 48// readystatechange events affect each other. 49// 50// In the comments for this class: 51// - "progress" event means an event named "progress" 52// - ProgressEvent means an event using the ProgressEvent interface defined in 53// the spec. 54class XMLHttpRequestProgressEventThrottle FINAL : public TimerBase { 55 DISALLOW_ALLOCATION(); 56public: 57 enum DeferredEventAction { 58 Ignore, 59 Clear, 60 Flush, 61 }; 62 63 explicit XMLHttpRequestProgressEventThrottle(EventTarget*); 64 virtual ~XMLHttpRequestProgressEventThrottle(); 65 66 // Dispatches a ProgressEvent. 67 // 68 // Special treatment for events named "progress" is implemented to dispatch 69 // them at the required frequency. If this object is suspended, the given 70 // ProgressEvent overwrites the existing. I.e. only the latest one gets 71 // queued. If the timer is running, this method just updates 72 // m_lengthComputable, m_loaded and m_total. They'll be used on next 73 // fired() call. 74 void dispatchProgressEvent(const AtomicString&, bool lengthComputable, unsigned long long loaded, unsigned long long total); 75 // Dispatches the given event after operation about the "progress" event 76 // depending on the value of the ProgressEventAction argument. 77 void dispatchReadyStateChangeEvent(PassRefPtrWillBeRawPtr<Event>, DeferredEventAction); 78 79 void suspend(); 80 void resume(); 81 82 void trace(Visitor*); 83 84private: 85 // The main purpose of this class is to throttle the "progress" 86 // ProgressEvent dispatching. This class represents such a deferred 87 // "progress" ProgressEvent. 88 class DeferredEvent; 89 static const double minimumProgressEventDispatchingIntervalInSeconds; 90 91 virtual void fired() OVERRIDE; 92 void dispatchDeferredEvent(); 93 94 // Non-Oilpan, keep a weak pointer to our XMLHttpRequest object as it is 95 // the one holding us. With Oilpan, a simple strong Member can be used - 96 // this XMLHttpRequestProgressEventThrottle (part) object dies together 97 // with the XMLHttpRequest object. 98 RawPtrWillBeMember<EventTarget> m_target; 99 100 // A slot for the deferred "progress" ProgressEvent. When multiple events 101 // arrive, only the last one is stored and others are discarded. 102 const OwnPtr<DeferredEvent> m_deferred; 103}; 104 105} // namespace blink 106 107#endif // XMLHttpRequestProgressEventThrottle_h 108