MemoryCache: Enable MemoryCache to have multiple isolated resource maps

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.
 
@@ skipping 151 matching lines @@
 
     struct Statistics {
         TypeStatistic images;
         TypeStatistic cssStyleSheets;
         TypeStatistic scripts;
         TypeStatistic xslStyleSheets;
         TypeStatistic fonts;
         TypeStatistic other;
     };
 
-    Resource* resourceForURL(const KURL&);
+    Resource* resourceForURL(const String& cacheIdentifier, const KURL&);

[Mike West, 2014/10/24 12:43:00]

If you make |cacheIdentifier| the second argument, you can make it optional, and
avoid modifications at the various call sites that don't care about SW.

[nhiroki, 2014/10/27 14:30:13]

Done.

+    WillBeHeapVector<Member<Resource>> resourcesForURL(const KURL&);
 
     void add(Resource*);
     void replace(Resource* newResource, Resource* oldResource);
     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.
     //  - minDeadBytes: The maximum number of bytes that dead resources should consume when the cache is under pressure.
     //  - maxDeadBytes: The maximum number of bytes that dead resources should consume when the cache is not under pressure.
     //  - totalBytes: The maximum number of bytes that the cache should consume overall.
     void setCapacities(size_t minDeadBytes, size_t maxDeadBytes, size_t totalBytes);
     void setDelayBeforeLiveDecodedPrune(double seconds) { m_delayBeforeLiveDecodedPrune = seconds; }
     void setMaxPruneDeferralDelay(double seconds) { m_maxPruneDeferralDelay = seconds; }
 
     void evictResources();
@@ skipping 54 matching lines @@
     size_t deadCapacity() const;
 
     // pruneDeadResources() - Flush decoded and encoded data from resources not referenced by Web pages.
     // pruneLiveResources() - Flush decoded data from resources still referenced by Web pages.
     void pruneDeadResources(); // Automatically decide how much to prune.
     void pruneLiveResources();
     void pruneNow(double currentTime);
 
     bool evict(MemoryCacheEntry*);
 
+    MemoryCacheEntry* getEntryForResource(const Resource*) const;
+
     static void removeURLFromCacheInternal(ExecutionContext*, const KURL&);
 
     bool m_inPruneResources;
     bool m_prunePending;
     double m_maxPruneDeferralDelay;
     double m_pruneTimeStamp;
     double m_pruneFrameTimeStamp;
 
     size_t m_capacity;
     size_t m_minDeadCapacity;
     size_t m_maxDeadCapacity;
     size_t m_maxDeferredPruneDeadCapacity;
     double m_delayBeforeLiveDecodedPrune;
 
     size_t m_liveSize; // The number of bytes currently consumed by "live" resources in the cache.
     size_t m_deadSize; // The number of bytes currently consumed by "dead" resources in the cache.
 
     // Size-adjusted and popularity-aware LRU list collection for cache objects. This collection can hold
     // more resources than the cached resource map, since it can also hold "stale" multiple versions of objects that are
     // waiting to die when the clients referencing them go away.
     WillBeHeapVector<MemoryCacheLRUList, 32> m_allResources;
 
     // Lists just for live resources with decoded data. Access to this list is based off of painting the resource.
     // The lists are ordered by decode priority, with higher indices having higher priorities.
     MemoryCacheLRUList m_liveDecodedResources[MemoryCacheLiveResourcePriorityHigh + 1];
 
     // 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).
     typedef WillBeHeapHashMap<String, OwnPtrWillBeMember<MemoryCacheEntry>> ResourceMap;
-    ResourceMap m_resources;
+    typedef WillBeHeapHashMap<String, OwnPtrWillBeMember<ResourceMap>> ResourceMapIndex;

[Mike West, 2014/10/24 12:43:00]

Nit: These should be converted to the new `using` syntax.

[nhiroki, 2014/10/27 14:30:13]

Done.

+    ResourceMap* getResourceMap(const String& cacheIdentifier);
+    ResourceMapIndex m_resources;

[Mike West, 2014/10/24 12:43:00]

Nit: Perhaps `m_resourceMaps`, now?

[nhiroki, 2014/10/27 14:30:13]

Done.

 
 #if ENABLE(OILPAN)
     // Unlike m_allResources, m_liveResources is a set of Resource objects which
     // should not be deleted. m_allResources only contains on-cache Resource
     // objects.
     // FIXME: Can we remove manual lifetime management of Resource and this?
     HeapHashSet<Member<Resource>> m_liveResources;
     friend RawPtr<MemoryCache> replaceMemoryCacheForTesting(RawPtr<MemoryCache>);
 #endif
 
     friend class MemoryCacheTest;
 #ifdef MEMORY_CACHE_STATS
     Timer<MemoryCache> m_statsTimer;
 #endif
 };
 
 // Returns the global cache.
 MemoryCache* memoryCache();
 
 // Sets the global cache, used to swap in a test instance. Returns the old
 // MemoryCache object.
 PassOwnPtrWillBeRawPtr<MemoryCache> replaceMemoryCacheForTesting(PassOwnPtrWillBeRawPtr<MemoryCache>);
 
 }
 
 #endif