Improvements/additions to SkImageCache/SkLazyPixelRef.

include/ports/SkAshmemImageCache.h

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkAshmemImageCache_DEFINED
-#define SkAshmemImageCache_DEFINED
-
-#include "SkImageCache.h"
-#include "SkTDArray.h"
-#include "SkTypes.h"
-
-class SkAshmemImageCache : public SkImageCache {
-
-public:
-    /**
-     *  Get a pointer to the single global instance of SkAshmemImageCache.
-     */
-    static SkAshmemImageCache* GetAshmemImageCache();
-
-    virtual void* allocAndPinCache(size_t bytes, intptr_t* ID) SK_OVERRIDE;
-    virtual void* pinCache(intptr_t ID) SK_OVERRIDE;
-    virtual void releaseCache(intptr_t ID) SK_OVERRIDE;
-    virtual void throwAwayCache(intptr_t ID) SK_OVERRIDE;
-
-#ifdef SK_DEBUG
-    SkImageCache::CacheStatus getCacheStatus(intptr_t ID) const SK_OVERRIDE;
-
-    virtual ~SkAshmemImageCache();
-#endif
-
-private:
-    struct AshmemRec {
-        int    fFD;
-        void*  fAddr;
-        size_t fSize;
-#ifdef SK_DEBUG
-        bool   fPinned;
-
-        static int Compare(const AshmemRec*, const AshmemRec*);
-#endif
-    };
-
-    /**
-     *  Constructor is private. The correct way to get this cache is through
-     *  GetAshmemImageCache, so that all callers can get the single global.
-     */
-    SkAshmemImageCache();
-
-#ifdef SK_DEBUG
-    // Stores a list of AshmemRecs to track deletion.
-    SkTDArray<AshmemRec*> fRecs;
-
-    /**
-     *  Debug only function to add an AshmemRec to the list.
-     */
-    void appendRec(AshmemRec*);
-
-    /**
-     *  Return the index of AshmemRec.
-     */
-    int findRec(const AshmemRec*) const;
-#endif
-
-    /**
-     *  Deletes AshmemRec. In debug, also removes from the list.
-     */
-    void removeRec(AshmemRec*);
-};
-#endif // SkAshmemImageCache_DEFINED