WebFonts cache-aware timeout adaptation

third_party/WebKit/Source/core/css/RemoteFontFaceSource.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/RemoteFontFaceSource.h"
 
 #include "core/css/CSSCustomFontData.h"
 #include "core/css/CSSFontFace.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/dom/Document.h"
 #include "core/fetch/ResourceFetcher.h"
+#include "core/fetch/ResourceLoader.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/page/NetworkStateNotifier.h"
 #include "platform/Histogram.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/FontDescription.h"
 #include "platform/fonts/SimpleFontData.h"
 #include "public/platform/WebEffectiveConnectionType.h"
 #include "wtf/CurrentTime.h"
@@ skipping 27 matching lines @@
 }
 
 }  // namespace
 
 RemoteFontFaceSource::RemoteFontFaceSource(FontResource* font,
                                            CSSFontSelector* fontSelector,
                                            FontDisplay display)
     : m_font(font),
       m_fontSelector(fontSelector),
       m_display(display),
-      m_period(display == FontDisplaySwap ? SwapPeriod : BlockPeriod),
+      m_period(BlockPeriod),
       m_histograms(font->url().protocolIsData()
                        ? FontLoadHistograms::FromDataURL
                        : font->isLoaded() ? FontLoadHistograms::FromMemoryCache
                                           : FontLoadHistograms::FromUnknown,
                    m_display),
       m_isInterventionTriggered(false) {
   ThreadState::current()->registerPreFinalizer(this);
-  m_font->addClient(this);
 
   if (shouldTriggerWebFontsIntervention()) {
     m_isInterventionTriggered = true;
     m_period = SwapPeriod;
     m_fontSelector->document()->addConsoleMessage(ConsoleMessage::create(
         OtherMessageSource, InfoMessageLevel,
         "Slow network is detected. Fallback font will be used while loading: " +
             m_font->url().elidedString()));
   }
+
+  if (m_display == FontDisplaySwap && !shouldTriggerCacheAwareAdaptation())
+    m_period = SwapPeriod;
+
+  // Font loading callbacks may be called in addClient(), make sure |m_period|
+  // is properly set before calling.
+  m_font->addClient(this);
 }
 
 RemoteFontFaceSource::~RemoteFontFaceSource() {}
 
 void RemoteFontFaceSource::dispose() {
   m_font->removeClient(this);
   m_font = nullptr;
   pruneTable();
 }
 
@@ skipping 67 matching lines @@
 
   if (m_display == FontDisplayBlock ||
       (!m_isInterventionTriggered && m_display == FontDisplayAuto))
     switchToSwapPeriod();
   else if (m_display == FontDisplayFallback)
     switchToFailurePeriod();
 
   m_histograms.longLimitExceeded(m_isInterventionTriggered);
 }
 
+void RemoteFontFaceSource::willReloadAfterDiskCacheMiss(const FontResource*) {
+  DCHECK(m_font->isLoading());
+  if (m_display == FontDisplaySwap)
+    switchToSwapPeriod();
+}
+
 void RemoteFontFaceSource::switchToSwapPeriod() {
-  ASSERT(m_period == BlockPeriod);
+  DCHECK_EQ(m_period, BlockPeriod);
   m_period = SwapPeriod;
 
   pruneTable();
   if (m_face) {
     m_fontSelector->fontFaceInvalidated();
     m_face->didBecomeVisibleFallback(this);
   }
 
   m_histograms.recordFallbackTime(m_font.get());
 }
 
 void RemoteFontFaceSource::switchToFailurePeriod() {
   if (m_period == BlockPeriod)
     switchToSwapPeriod();
-  ASSERT(m_period == SwapPeriod);
+  DCHECK_EQ(m_period, SwapPeriod);
   m_period = FailurePeriod;
 }
 
 bool RemoteFontFaceSource::shouldTriggerWebFontsIntervention() {
   if (RuntimeEnabledFeatures::webFontsInterventionTriggerEnabled())
     return true;
   if (m_histograms.dataSource() == FontLoadHistograms::FromMemoryCache ||
       m_histograms.dataSource() == FontLoadHistograms::FromDataURL)
     return false;
 
   bool isV2Enabled =
       RuntimeEnabledFeatures::webFontsInterventionV2With2GEnabled() ||
       RuntimeEnabledFeatures::webFontsInterventionV2With3GEnabled() ||
       RuntimeEnabledFeatures::webFontsInterventionV2WithSlow2GEnabled();
 
   bool networkIsSlow =
       isV2Enabled ? isEffectiveConnectionTypeSlowFor(m_fontSelector->document())
                   : isConnectionTypeSlow();
 
   return networkIsSlow && m_display == FontDisplayAuto;
 }
 
+bool RemoteFontFaceSource::shouldTriggerCacheAwareAdaptation() {
+  if (m_font->stillNeedsLoad() &&
+      m_font->options().cacheAwareLoadingEnabled == IsCacheAwareLoadingEnabled)
+    return true;
+  if (m_font->isLoading() && m_font->loader()->isCacheAwareLoadingActivated())
+    return true;
+  // willReloadAfterDiskCacheMiss() will not be called.
+  return false;
+}
+
 PassRefPtr<SimpleFontData> RemoteFontFaceSource::createFontData(
     const FontDescription& fontDescription) {
   if (!isLoaded())
     return createLoadingFallbackFontData(fontDescription);
 
   if (!m_font->ensureCustomFontData() || m_period == FailurePeriod)
     return nullptr;
 
   m_histograms.recordFallbackTime(m_font.get());
 
@@ skipping 239 matching lines @@
       return Miss;
     case FromUnknown:
     // Fall through.
     default:
       NOTREACHED();
   }
   return Miss;
 }
 
 }  // namespace blink