Fix under-invalidation of media buffered ranges

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Google Inc. All rights 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
@@ skipping 14 matching lines @@
  */
 
 #include "core/html/shadow/MediaControls.h"
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/dom/ClientRect.h"
 #include "core/dom/Fullscreen.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLMediaElement.h"
+#include "core/html/TimeRanges.h"
 #include "core/html/track/TextTrackContainer.h"
 #include "core/layout/LayoutTheme.h"
 #include "platform/EventDispatchForbiddenScope.h"
 
 namespace blink {
 
 // If you change this value, then also update the corresponding value in
 // LayoutTests/media/media-controls.js.
 static const double timeWithoutMouseMovementBeforeHidingMediaControls = 3;
 
@@ skipping 74 matching lines @@
     , m_textTrackList(nullptr)
     , m_castButton(nullptr)
     , m_fullScreenButton(nullptr)
     , m_hideMediaControlsTimer(this, &MediaControls::hideMediaControlsTimerFired)
     , m_hideTimerBehaviorFlags(IgnoreNone)
     , m_isMouseOverControls(false)
     , m_isPausedForScrubbing(false)
     , m_panelWidthChangedTimer(this, &MediaControls::panelWidthChangedTimerFired)
     , m_panelWidth(0)
     , m_allowHiddenVolumeControls(RuntimeEnabledFeatures::newMediaPlaybackUiEnabled())
+    , m_bufferedRangesPaintInvalidationTimer(this, &MediaControls::bufferedRangesPaintInvalidationTimerFired)
 {
 }
 
 MediaControls* MediaControls::create(HTMLMediaElement& mediaElement)
 {
     MediaControls* controls = new MediaControls(mediaElement);
     controls->setShadowPseudoId(AtomicString("-webkit-media-controls"));
     controls->initializeControls();
     return controls;
 }
@@ skipping 129 matching lines @@
 
     // If the player has entered an error state, force it into the paused state.
     if (mediaElement().error())
         mediaElement().pause();
 
     updatePlayState();
 
     updateCurrentTimeDisplay();
 
     m_timeline->setDuration(duration);
-    m_timeline->setPosition(mediaElement().currentTime());
+    updateTimelinePosition();
 
     updateVolume();
 
     refreshClosedCaptionsButtonVisibility();
 
     m_fullScreenButton->setIsWanted(shouldShowFullscreenButton(mediaElement()));
 
     refreshCastButtonVisibilityWithoutUpdate();
 }
 
@@ skipping 65 matching lines @@
 void MediaControls::playbackStarted()
 {
     BatchedControlUpdate batch(this);
 
     if (!RuntimeEnabledFeatures::newMediaPlaybackUiEnabled()) {
         m_currentTimeDisplay->setIsWanted(true);
         m_durationDisplay->setIsWanted(false);
     }
 
     updatePlayState();
-    m_timeline->setPosition(mediaElement().currentTime());
+    updateTimelinePosition();
     updateCurrentTimeDisplay();
 
     startHideMediaControlsTimer();
 }
 
 void MediaControls::playbackProgressed()
 {
-    m_timeline->setPosition(mediaElement().currentTime());
+    updateTimelinePosition();
     updateCurrentTimeDisplay();
 
     if (shouldHideMediaControls())
         makeTransparent();
 }
 
 void MediaControls::playbackStopped()
 {
     updatePlayState();
-    m_timeline->setPosition(mediaElement().currentTime());
+    updateTimelinePosition();
     updateCurrentTimeDisplay();
     makeOpaque();
 
     stopHideMediaControlsTimer();
 }
 
 void MediaControls::updatePlayState()
 {
     if (m_isPausedForScrubbing)
         return;
@@ skipping 374 matching lines @@
 
 void MediaControls::invalidate(Element* element)
 {
     if (!element)
         return;
 
     if (LayoutObject* layoutObject = element->layoutObject())
         layoutObject->setShouldDoFullPaintInvalidation();
 }
 
+static const double kBufferedRangesPaintInvalidationInterval = 0.5;
+
 void MediaControls::networkStateChanged()
 {
     invalidate(m_playButton);
     invalidate(m_overlayPlayButton);
     invalidate(m_muteButton);
     invalidate(m_fullScreenButton);
     invalidate(m_timeline);
     invalidate(m_volumeSlider);
+
+    updateBufferedRanges();
+    if (m_mediaElement->getNetworkState() == HTMLMediaElement::kNetworkLoading) {
+        if (!m_bufferedRangesPaintInvalidationTimer.isActive())
+            m_bufferedRangesPaintInvalidationTimer.startRepeating(kBufferedRangesPaintInvalidationInterval, BLINK_FROM_HERE);
+    } else {
+        m_bufferedRangesPaintInvalidationTimer.stop();
+    }
+}
+
+void MediaControls::updateTimelinePosition()
+{
+    m_timeline->setPosition(mediaElement().currentTime());
+    // Synchronize buffered ranges when the current time change.
+    updateBufferedRanges();
+}
+
+void MediaControls::updateBufferedRanges()
+{
+    TimeRanges* newBuffered = m_mediaElement->buffered();
+    if (!m_bufferedRangesForPainting) {
+        if (!newBuffered->length())
+            return;
+    } else if (*m_bufferedRangesForPainting == *newBuffered) {

[liberato (no reviews please), 2016/08/29 15:25:34]

might one just unconditionally invalidate the timeline, and avoid the complexity
of buffering and checking for equality?

or, to put it another way, how many invalidations does this actually save?  it's
only the timer case that it matters; setPosition via updateTimelinePosition
always invalidates anyway, i think.

[Xianzhu, 2016/08/29 18:04:14]

Good question. It's unlikely to save invalidations using the comparison. Changed
to unconditional. Along with the change in MediaControlsPainter, the CL is much
simplified.

+        return;
+    }
+
+    m_bufferedRangesForPainting = newBuffered;
+    invalidate(m_timeline);
+}
+
+void MediaControls::bufferedRangesPaintInvalidationTimerFired(TimerBase*)
+{
+    updateBufferedRanges();
 }
 
 DEFINE_TRACE(MediaControls)
 {
     visitor->trace(m_mediaElement);
     visitor->trace(m_panel);
     visitor->trace(m_overlayPlayButton);
     visitor->trace(m_overlayEnclosure);
     visitor->trace(m_playButton);
     visitor->trace(m_currentTimeDisplay);
     visitor->trace(m_timeline);
     visitor->trace(m_muteButton);
     visitor->trace(m_volumeSlider);
     visitor->trace(m_toggleClosedCaptionsButton);
     visitor->trace(m_fullScreenButton);
     visitor->trace(m_durationDisplay);
     visitor->trace(m_enclosure);
     visitor->trace(m_textTrackList);
     visitor->trace(m_castButton);
     visitor->trace(m_overlayCastButton);
+    visitor->trace(m_bufferedRangesForPainting);
     HTMLDivElement::trace(visitor);
 }
 
 } // namespace blink