Revert of Rename XMLHttpRequestProgressEventThrottle to ProgressEventThrottle

third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.h

+/*
+ * Copyright (C) 2010 Julien Chaffraix <jchaffraix@webkit.org>
+ * All right 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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef XMLHttpRequestProgressEventThrottle_h
+#define XMLHttpRequestProgressEventThrottle_h
+
+#include "platform/Timer.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Forward.h"
+#include "wtf/PassRefPtr.h"
+
+namespace blink {
+
+class Event;
+class XMLHttpRequest;
+
+// This class implements the XHR2 ProgressEvent dispatching:
+//   "dispatch a progress event named progress about every 50ms or for every
+//   byte received, whichever is least frequent".
+//
+// readystatechange events also go through this class since ProgressEvents and
+// readystatechange events affect each other.
+//
+// In the comments for this class:
+// - "progress" event means an event named "progress"
+// - ProgressEvent means an event using the ProgressEvent interface defined in
+//   the spec.
+class XMLHttpRequestProgressEventThrottle final : public GarbageCollectedFinalized<XMLHttpRequestProgressEventThrottle>, public TimerBase {
+public:
+    static XMLHttpRequestProgressEventThrottle* create(XMLHttpRequest* eventTarget)
+    {
+        return new XMLHttpRequestProgressEventThrottle(eventTarget);
+    }
+    ~XMLHttpRequestProgressEventThrottle() override;
+
+    enum DeferredEventAction {
+        Ignore,
+        Clear,
+        Flush,
+    };
+
+    // Dispatches a ProgressEvent.
+    //
+    // Special treatment for events named "progress" is implemented to dispatch
+    // them at the required frequency. If this object is suspended, the given
+    // ProgressEvent overwrites the existing. I.e. only the latest one gets
+    // queued. If the timer is running, this method just updates
+    // m_lengthComputable, m_loaded and m_total. They'll be used on next
+    // fired() call.
+    // For an event named "progress", a readyStateChange will be dispatched
+    // as well.
+    void dispatchProgressEvent(const AtomicString&, bool lengthComputable, unsigned long long loaded, unsigned long long total);
+    // Dispatches the given event after operation about the "progress" event
+    // depending on the value of the ProgressEventAction argument.
+    void dispatchReadyStateChangeEvent(PassRefPtrWillBeRawPtr<Event>, DeferredEventAction);
+
+    void suspend();
+    void resume();
+
+    // Need to promptly stop this timer when it is deemed finalizable.
+    EAGERLY_FINALIZE();
+    DECLARE_TRACE();
+
+private:
+    explicit XMLHttpRequestProgressEventThrottle(XMLHttpRequest*);
+
+    // Dispatches a "progress" progress event and usually a readyStateChange
+    // event as well.
+    void dispatchProgressProgressEvent(PassRefPtrWillBeRawPtr<Event>);
+
+    // The main purpose of this class is to throttle the "progress"
+    // ProgressEvent dispatching. This class represents such a deferred
+    // "progress" ProgressEvent.
+    class DeferredEvent {
+    public:
+        DeferredEvent();
+        void set(bool lengthComputable, unsigned long long loaded, unsigned long long total);
+        void clear();
+        bool isSet() const { return m_isSet; }
+        PassRefPtrWillBeRawPtr<Event> take();
+
+    private:
+        unsigned long long m_loaded;
+        unsigned long long m_total;
+        bool m_lengthComputable;
+
+        bool m_isSet;
+    };
+
+    static const double minimumProgressEventDispatchingIntervalInSeconds;
+
+    void fired() override;
+
+    Member<XMLHttpRequest> m_target;
+
+    // A slot for the deferred "progress" ProgressEvent. When multiple events
+    // arrive, only the last one is stored and others are discarded.
+    DeferredEvent m_deferred;
+
+    // True if any "progress" progress event has been dispatched since
+    // |m_target|'s readyState changed.
+    bool m_hasDispatchedProgressProgressEvent;
+};
+
+} // namespace blink
+
+#endif // XMLHttpRequestProgressEventThrottle_h