Improvements/additions to SkImageCache/SkLazyPixelRef.

include/ports/SkMacImageCache.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 SkMacImageCache_DEFINED
+#define SkMacImageCache_DEFINED
+
+#include "SkImageCache.h"
+
+#ifdef SK_DEBUG
+    #include "SkTDArray.h"
+#endif
+
+#include <mach/mach.h>
+
+
+/**
+ *  Interface for a cache that manages pixel memory.
+ */
+class SkMacImageCache : public SkImageCache {
+
+public:
+    /**
+     *  Get a pointer to the single global instance of SkMacImageCache.
+     */
+    static SkMacImageCache* GetMacImageCache();
+
+    virtual void* allocAndPinCache(size_t bytes, intptr_t* ID) SK_OVERRIDE;
+    virtual void* pinCache(intptr_t ID, SkImageCache::PurgeStatus*) SK_OVERRIDE;
+    virtual void releaseCache(intptr_t ID) SK_OVERRIDE;
+    virtual void throwAwayCache(intptr_t ID) SK_OVERRIDE;
+
+#ifdef SK_DEBUG
+    virtual PinStatus getPinStatus(intptr_t ID) const SK_OVERRIDE;
+    virtual void purgeAllCaches() SK_OVERRIDE;
+    virtual ~SkMacImageCache();
+#endif
+
+private:
+    /**
+     *  Constructor is private. The correct way to get this cache is through
+     *  GetMacImageCache, so that all callers can get the single global.
+     */
+    SkMacImageCache();
+
+    struct Rec {
+        vm_address_t fAddr;
+        vm_size_t    fSize;
+#ifdef SK_DEBUG
+        bool         fPinned;
+#endif
+    };
+
+#ifdef SK_DEBUG
+    SkTDArray<intptr_t> fRecs;
+    int findRec(intptr_t) const;
+#endif
+    void removeRec(intptr_t);
+};
+#endif // SkMacImageCache_DEFINED