Loading: move core/fetch to platform/loader/fetch

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

-/*
-    Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
-    Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
-    Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Library General Public
-    License as published by the Free Software Foundation; either
-    version 2 of the License, or (at your option) any later version.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Library General Public License for more details.
-
-    You should have received a copy of the GNU Library General Public License
-    along with this library; see the file COPYING.LIB.  If not, write to
-    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-    Boston, MA 02110-1301, USA.
-
-    This class provides all functionality needed for loading images, style
-   sheets and html
-    pages from the web. It has a memory cache for these objects.
-*/
-
-#ifndef MemoryCache_h
-#define MemoryCache_h
-
-#include "core/CoreExport.h"
-#include "core/fetch/Resource.h"
-#include "platform/MemoryCoordinator.h"
-#include "platform/instrumentation/tracing/MemoryCacheDumpProvider.h"
-#include "public/platform/WebThread.h"
-#include "wtf/Allocator.h"
-#include "wtf/HashMap.h"
-#include "wtf/Noncopyable.h"
-#include "wtf/Vector.h"
-#include "wtf/text/StringHash.h"
-#include "wtf/text/WTFString.h"
-
-namespace blink {
-
-class KURL;
-
-// Member<MemoryCacheEntry> + MemoryCacheEntry::clearResourceWeak() monitors
-// eviction from MemoryCache due to Resource garbage collection.
-// WeakMember<Resource> + Resource's prefinalizer cannot determine whether the
-// Resource was on MemoryCache or not, because WeakMember is already cleared
-// when the prefinalizer is executed.
-class MemoryCacheEntry final : public GarbageCollected<MemoryCacheEntry> {
- public:
-  static MemoryCacheEntry* create(Resource* resource) {
-    return new MemoryCacheEntry(resource);
-  }
-  DECLARE_TRACE();
-  Resource* resource() const { return m_resource; }
-
-  double m_lastDecodedAccessTime;  // Used as a thrash guard
-
- private:
-  explicit MemoryCacheEntry(Resource* resource)
-      : m_lastDecodedAccessTime(0.0), m_resource(resource) {}
-
-  void clearResourceWeak(Visitor*);
-
-  WeakMember<Resource> m_resource;
-};
-
-WILL_NOT_BE_EAGERLY_TRACED_CLASS(MemoryCacheEntry);
-
-// This cache holds subresources used by Web pages: images, scripts,
-// stylesheets, etc.
-class CORE_EXPORT MemoryCache final
-    : public GarbageCollectedFinalized<MemoryCache>,
-      public WebThread::TaskObserver,
-      public MemoryCacheDumpClient,
-      public MemoryCoordinatorClient {
-  USING_GARBAGE_COLLECTED_MIXIN(MemoryCache);
-  WTF_MAKE_NONCOPYABLE(MemoryCache);
-
- public:
-  static MemoryCache* create();
-  ~MemoryCache();
-  DECLARE_TRACE();
-
-  struct TypeStatistic {
-    STACK_ALLOCATED();
-    size_t count;
-    size_t size;
-    size_t decodedSize;
-    size_t encodedSize;
-    size_t overheadSize;
-    size_t encodedSizeDuplicatedInDataURLs;
-
-    TypeStatistic()
-        : count(0),
-          size(0),
-          decodedSize(0),
-          encodedSize(0),
-          overheadSize(0),
-          encodedSizeDuplicatedInDataURLs(0) {}
-
-    void addResource(Resource*);
-  };
-
-  struct Statistics {
-    STACK_ALLOCATED();
-    TypeStatistic images;
-    TypeStatistic cssStyleSheets;
-    TypeStatistic scripts;
-    TypeStatistic xslStyleSheets;
-    TypeStatistic fonts;
-    TypeStatistic other;
-  };
-
-  Resource* resourceForURL(const KURL&) const;
-  Resource* resourceForURL(const KURL&, const String& cacheIdentifier) const;
-  HeapVector<Member<Resource>> resourcesForURL(const KURL&) const;
-
-  void add(Resource*);
-  void remove(Resource*);
-  bool contains(const Resource*) const;
-
-  static KURL removeFragmentIdentifierIfNeeded(const KURL& originalURL);
-
-  static String defaultCacheIdentifier();
-
-  // Sets the cache's memory capacities, in bytes. These will hold only
-  // approximately, since the decoded cost of resources like scripts and
-  // stylesheets is not known.
-  //  - totalBytes: The maximum number of bytes that the cache should consume
-  //    overall.
-  void setCapacity(size_t totalBytes);
-  void setDelayBeforeLiveDecodedPrune(double seconds) {
-    m_delayBeforeLiveDecodedPrune = seconds;
-  }
-  void setMaxPruneDeferralDelay(double seconds) {
-    m_maxPruneDeferralDelay = seconds;
-  }
-
-  enum EvictResourcePolicy { EvictAllResources, DoNotEvictUnusedPreloads };
-  void evictResources(EvictResourcePolicy = EvictAllResources);
-
-  void prune();
-
-  // Called to update MemoryCache::size().
-  void update(Resource*, size_t oldSize, size_t newSize);
-
-  void removeURLFromCache(const KURL&);
-
-  Statistics getStatistics() const;
-
-  size_t capacity() const { return m_capacity; }
-  size_t size() const { return m_size; }
-
-  // TaskObserver implementation
-  void willProcessTask() override;
-  void didProcessTask() override;
-
-  void pruneAll();
-
-  void updateFramePaintTimestamp();
-
-  // Take memory usage snapshot for tracing.
-  bool onMemoryDump(WebMemoryDumpLevelOfDetail, WebProcessMemoryDump*) override;
-
-  void onMemoryPressure(WebMemoryPressureLevel) override;
-
- private:
-  enum PruneStrategy {
-    // Automatically decide how much to prune.
-    AutomaticPrune,
-    // Maximally prune resources.
-    MaximalPrune
-  };
-
-  // A URL-based map of all resources that are in the cache (including the
-  // freshest version of objects that are currently being referenced by a Web
-  // page). removeFragmentIdentifierIfNeeded() should be called for the url
-  // before using it as a key for the map.
-  using ResourceMap = HeapHashMap<String, Member<MemoryCacheEntry>>;
-  using ResourceMapIndex = HeapHashMap<String, Member<ResourceMap>>;
-  ResourceMap* ensureResourceMap(const String& cacheIdentifier);
-  ResourceMapIndex m_resourceMaps;
-
-  MemoryCache();
-
-  void addInternal(ResourceMap*, MemoryCacheEntry*);
-  void removeInternal(ResourceMap*, const ResourceMap::iterator&);
-
-  void pruneResources(PruneStrategy);
-  void pruneNow(double currentTime, PruneStrategy);
-
-  bool m_inPruneResources;
-  bool m_prunePending;
-  double m_maxPruneDeferralDelay;
-  double m_pruneTimeStamp;
-  double m_pruneFrameTimeStamp;
-  double m_lastFramePaintTimeStamp;  // used for detecting decoded resource
-                                     // thrash in the cache
-
-  size_t m_capacity;
-  double m_delayBeforeLiveDecodedPrune;
-
-  // The number of bytes currently consumed by resources in the cache.
-  size_t m_size;
-
-  friend class MemoryCacheTest;
-};
-
-// Returns the global cache.
-CORE_EXPORT MemoryCache* memoryCache();
-
-// Sets the global cache, used to swap in a test instance. Returns the old
-// MemoryCache object.
-CORE_EXPORT MemoryCache* replaceMemoryCacheForTesting(MemoryCache*);
-
-}  // namespace blink
-
-#endif