[XHR] Decrease readyStateChange event dispatching during loading.

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

 /*
  * Copyright (C) 2010 Julien Chaffraix <jchaffraix@webkit.org>  All right reserved.
  * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 10 matching lines @@
  * 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 "core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.h"
 
 #include "core/EventTypeNames.h"
+#include "core/inspector/InspectorInstrumentation.h"
+#include "core/inspector/InspectorTraceEvents.h"
 #include "core/xmlhttprequest/XMLHttpRequest.h"
 #include "core/xmlhttprequest/XMLHttpRequestProgressEvent.h"
 #include "wtf/Assertions.h"
 #include "wtf/text/AtomicString.h"
 
 namespace blink {
 
 class XMLHttpRequestProgressEventThrottle::DeferredEvent {
 public:
     DeferredEvent() { clear(); }
@@ skipping 21 matching lines @@
     unsigned long long m_total;
     bool m_isDeferred;
     bool m_lengthComputable;
 };
 
 const double XMLHttpRequestProgressEventThrottle::minimumProgressEventDispatchingIntervalInSeconds = .05; // 50 ms per specification.
 
 XMLHttpRequestProgressEventThrottle::XMLHttpRequestProgressEventThrottle(XMLHttpRequest* target)
     : m_target(target)
     , m_deferred(adoptPtr(new DeferredEvent))
+    , m_hasDispatchedProgressProgressEvent(false)
 {
     ASSERT(target);
 }
 
 XMLHttpRequestProgressEventThrottle::~XMLHttpRequestProgressEventThrottle()
 {
 }
 
 void XMLHttpRequestProgressEventThrottle::dispatchProgressEvent(const AtomicString& type, bool lengthComputable, unsigned long long loaded, unsigned long long total)
 {
     // Given that ResourceDispatcher doesn't deliver an event when suspended,
     // we don't have to worry about event dispatching while suspended.
     if (type != EventTypeNames::progress) {
         m_target->dispatchEvent(XMLHttpRequestProgressEvent::create(type, lengthComputable, loaded, total));
         return;
     }
 
     if (isActive()) {
         m_deferred->set(lengthComputable, loaded, total);
     } else {
-        m_target->dispatchEvent(XMLHttpRequestProgressEvent::create(type, lengthComputable, loaded, total));
+        dispatchProgressProgressEvent(lengthComputable, loaded, total);
         startOneShot(minimumProgressEventDispatchingIntervalInSeconds, BLINK_FROM_HERE);
     }
 }
 
 void XMLHttpRequestProgressEventThrottle::dispatchReadyStateChangeEvent(PassRefPtrWillBeRawPtr<Event> event, DeferredEventAction action)
 {
     XMLHttpRequest::State state = m_target->readyState();
     // Given that ResourceDispatcher doesn't deliver an event when suspended,
     // we don't have to worry about event dispatching while suspended.
     if (action == Flush) {
         dispatchDeferredEvent();
-        // |m_target| is protected by the caller.
         stop();
     } else if (action == Clear) {
         m_deferred->clear();
         stop();
     }
 
+    m_hasDispatchedProgressProgressEvent = false;
     if (state == m_target->readyState()) {
         // We don't dispatch the event when an event handler associated with
         // the previously dispatched event changes the readyState (e.g. when
         // the event handler calls xhr.abort()). In such cases a
         // readystatechange should have been already dispatched if necessary.
         m_target->dispatchEvent(event);
     }
 }
 
+void XMLHttpRequestProgressEventThrottle::dispatchProgressProgressEvent(bool lengthComputable, unsigned long long loaded, unsigned long long total)
+{

[tyoshino (SeeGerritForStatus), 2015/11/26 07:04:13]

are we sure that we can omit "if (!executionContext())" that we have in
XMLHttpRequest::dispatchReadyStateChangeEvent() now

[yhirano, 2015/11/26 11:36:32]

I'm not sure what the block is for. I added a |stop| call in
XMLHttpRequest::stop in order to stop the timer when the execution context is
stopped.

+    XMLHttpRequest::State state = m_target->readyState();
+    if (m_target->readyState() == XMLHttpRequest::LOADING && m_hasDispatchedProgressProgressEvent) {
+        TRACE_EVENT1("devtools.timeline", "XHRReadyStateChange", "data", InspectorXhrReadyStateChangeEvent::data(m_target->executionContext(), m_target));
+        m_target->dispatchEvent(Event::create(EventTypeNames::readystatechange));
+        TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "UpdateCounters", TRACE_EVENT_SCOPE_THREAD, "data", InspectorUpdateCountersEvent::data());
+    }
+
+    if (m_target->readyState() != state)
+        return;
+
+    m_hasDispatchedProgressProgressEvent = true;
+    m_target->dispatchEvent(XMLHttpRequestProgressEvent::create(EventTypeNames::progress, lengthComputable, loaded, total));
+}
+
 void XMLHttpRequestProgressEventThrottle::dispatchDeferredEvent()
 {
     if (m_deferred->isDeferred()) {
-        m_target->dispatchEvent(XMLHttpRequestProgressEvent::create(EventTypeNames::progress, m_deferred->lengthComputable(), m_deferred->loaded(), m_deferred->total()));
+        dispatchProgressProgressEvent(m_deferred->lengthComputable(), m_deferred->loaded(), m_deferred->total());
         m_deferred->clear();
     }
 }
 
 void XMLHttpRequestProgressEventThrottle::fired()
 {
     if (!m_deferred->isDeferred()) {
         // No "progress" event was queued since the previous dispatch, we can
         // safely stop the timer.
         return;
@@ skipping 20 matching lines @@
     // event-handler could insert new active DOM objects to the list.
     startOneShot(0, BLINK_FROM_HERE);
 }
 
 DEFINE_TRACE(XMLHttpRequestProgressEventThrottle)
 {
     visitor->trace(m_target);
 }
 
 } // namespace blink