WebFonts cache-aware timeout adaptation

third_party/WebKit/Source/core/fetch/FontResource.h

 /*
  * Copyright (C) 2007, 2008 Apple 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
  *    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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 #ifndef FontResource_h
 #define FontResource_h
 
+#include "base/gtest_prod_util.h"
 #include "core/CoreExport.h"
 #include "core/fetch/Resource.h"
 #include "core/fetch/ResourceClient.h"
 #include "platform/Timer.h"
 #include "platform/fonts/FontOrientation.h"
 #include "platform/heap/Handle.h"
 #include <memory>
 
 namespace blink {
 
@@ skipping 26 matching lines @@
       float size,
       bool bold,
       bool italic,
       FontOrientation = FontOrientation::Horizontal);
 
   // Returns true if the loading priority of the remote font resource can be
   // lowered. The loading priority of the font can be lowered only if the
   // font is not needed for painting the text.
   bool isLowPriorityLoadingAllowedForRemoteFont() const;
 
+  void willReloadAfterDiskCacheMiss() override;
+
  private:
   class FontResourceFactory : public ResourceFactory {
    public:
     FontResourceFactory() : ResourceFactory(Resource::Font) {}
 
     Resource* create(const ResourceRequest& request,
                      const ResourceLoaderOptions& options,
                      const String& charset) const override {
       return new FontResource(request, options);
     }
   };
   FontResource(const ResourceRequest&, const ResourceLoaderOptions&);
 
   void checkNotify() override;
   void fontLoadShortLimitCallback(TimerBase*);
   void fontLoadLongLimitCallback(TimerBase*);
+  void notifyClientsShortLimitExceeded();
+  void notifyClientsLongLimitExceeded();
 
+  // This is used in UMA histograms, should not change order.
   enum LoadLimitState {
     LoadNotStarted,
     UnderLimit,
     ShortLimitExceeded,
-    LongLimitExceeded
+    LongLimitExceeded,
+    LoadLimitStateEnumMax
   };
 
   std::unique_ptr<FontCustomPlatformData> m_fontData;
   String m_otsParsingMessage;
   LoadLimitState m_loadLimitState;
   bool m_corsFailed;
   Timer<FontResource> m_fontLoadShortLimitTimer;
   Timer<FontResource> m_fontLoadLongLimitTimer;
 
   friend class MemoryCache;
+  FRIEND_TEST_ALL_PREFIXES(ResourceFetcherTest, CacheAwareFontLoading);
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Font);
 
 class FontResourceClient : public ResourceClient {
  public:
   ~FontResourceClient() override {}
   static bool isExpectedType(ResourceClient* client) {
     return client->getResourceClientType() == FontType;
   }
   ResourceClientType getResourceClientType() const final { return FontType; }
+
+  // If cache-aware loading is activated, both callbacks will be blocked until
+  // disk cache miss. Calls to addClient() and removeClient() in both callbacks
+  // are prohibited to prevent race issues regarding current loading state.
   virtual void fontLoadShortLimitExceeded(FontResource*) {}
   virtual void fontLoadLongLimitExceeded(FontResource*) {}
 
   // Returns true if loading priority of remote font resources can be lowered.
   virtual bool isLowPriorityLoadingAllowedForRemoteFont() const {
     // Only the RemoteFontFaceSources clients can prevent lowering of loading
     // priority of the remote fonts.  Set the default to true to prevent
     // other clients from incorrectly returning false.
     return true;
   }
 };
 
 }  // namespace blink
 
 #endif