--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/xml/XMLHttpRequestProgressEventThrottle.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,154 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "XMLHttpRequestProgressEventThrottle.h"
+
+#include "EventTarget.h"
+#include "XMLHttpRequestProgressEvent.h"
+
+namespace WebCore {
+
+const double XMLHttpRequestProgressEventThrottle::minimumProgressEventDispatchingIntervalInSeconds = .05; // 50 ms per specification.
+
+XMLHttpRequestProgressEventThrottle::XMLHttpRequestProgressEventThrottle(EventTarget* target)
+    : m_target(target)
+    , m_loaded(0)
+    , m_total(0)
+    , m_suspended(false)
+{
+    ASSERT(target);
+}
+
+XMLHttpRequestProgressEventThrottle::~XMLHttpRequestProgressEventThrottle()
+{
+}
+
+void XMLHttpRequestProgressEventThrottle::dispatchProgressEvent(bool lengthComputable, unsigned loaded, unsigned total)
+{
+    ASSERT(!suspended());
+    if (!isActive()) {
+        // The timer is not active so the least frequent event for now is every byte.
+        // Just go ahead and dispatch the event.
+
+        // We should not have any pending loaded & total information from a previous run.
+        ASSERT(!m_loaded);
+        ASSERT(!m_total);
+
+        dispatchEvent(XMLHttpRequestProgressEvent::create(eventNames().progressEvent, lengthComputable, loaded, total));
+        startRepeating(minimumProgressEventDispatchingIntervalInSeconds);
+        return;
+    }
+
+    // The timer is already active so minimumProgressEventDispatchingIntervalInSeconds is the least frequent event.
+    m_lengthComputable = lengthComputable;
+    m_loaded = loaded;
+    m_total = total;
+}
+
+void XMLHttpRequestProgressEventThrottle::dispatchEvent(PassRefPtr<Event> event, ProgressEventAction progressEventAction)
+{
+    ASSERT(!suspended());
+    // We should not have any pending events from a previous resume.
+    ASSERT(!m_pausedEvent);
+
+    if (progressEventAction == FlushProgressEvent)
+        flushProgressEvent();
+
+    m_target->dispatchEvent(event);
+}
+
+void XMLHttpRequestProgressEventThrottle::flushProgressEvent()
+{
+    if (!hasEventToDispatch())
+        return;
+
+    PassRefPtr<Event> event = XMLHttpRequestProgressEvent::create(eventNames().progressEvent, m_lengthComputable, m_loaded, m_total);
+    m_loaded = 0;
+    m_total = 0;
+
+    // We stop the timer as this is called when no more events are supposed to occur.
+    stop();
+
+    m_target->dispatchEvent(event);
+}
+
+void XMLHttpRequestProgressEventThrottle::dispatchPausedEvent()
+{
+    ASSERT(!suspended());
+    if (!m_pausedEvent)
+        return;
+
+    m_target->dispatchEvent(m_pausedEvent);
+    m_pausedEvent = 0;
+}
+
+void XMLHttpRequestProgressEventThrottle::fired()
+{
+    ASSERT(isActive());
+    ASSERT(!suspended());
+    ASSERT(!m_pausedEvent);
+    if (!hasEventToDispatch()) {
+        // No progress event was queued since the previous dispatch, we can safely stop the timer.
+        stop();
+        return;
+    }
+
+    m_target->dispatchEvent(XMLHttpRequestProgressEvent::create(eventNames().progressEvent, m_lengthComputable, m_loaded, m_total));
+    m_total = 0;
+    m_loaded = 0;
+}
+
+bool XMLHttpRequestProgressEventThrottle::hasEventToDispatch() const
+{
+    return (m_total || m_loaded) && isActive();
+}
+
+void XMLHttpRequestProgressEventThrottle::suspend()
+{
+    ASSERT(!m_pausedEvent);
+
+    m_suspended = true;
+    // If we have a progress event waiting to be dispatched,
+    // just queue it.
+    if (hasEventToDispatch()) {
+        m_pausedEvent = XMLHttpRequestProgressEvent::create(eventNames().progressEvent, m_lengthComputable, m_loaded, m_total);
+        m_total = 0;
+        m_loaded = 0;
+    }
+    stop();
+}
+
+void XMLHttpRequestProgressEventThrottle::resume()
+{
+    ASSERT(!m_loaded);
+    ASSERT(!m_total);
+
+    m_suspended = false;
+    dispatchPausedEvent();
+}
+
+} // namespace WebCore