SkDiscardableMemory::Factory class

include/lazy/SkImageCache.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 SkImageCache_DEFINED
 #define SkImageCache_DEFINED
 
-#include "SkRefCnt.h"
+#include "SkDiscardableMemory.h"
 #include "SkTypes.h"
 
 /**
  *  Interface for a cache that manages pixel memory.
  */
-class SkImageCache : public SkRefCnt {
-
+class SkImageCache : public SkDiscardableMemory::Factory {
 public:
     SK_DECLARE_INST_COUNT(SkImageCache)
 
     typedef intptr_t ID;
 
+    virtual SkDiscardableMemory* create(size_t bytes) SK_OVERRIDE;

[scroggo, 2013/12/02 19:00:09]

Need this be virtual? Can you imagine a different implementation for a subclass?

It also seems like it doesn't need to be on this class, since it only uses
public functions from this class.

Can you add comments?

+
     /**
      *  Allocate memory whose lifetime is managed by the cache. On success, MUST be balanced with a
      *  call to releaseCache and a call to throwAwayCache.
      *  @param bytes Number of bytes needed.
      *  @param ID Output parameter which must not be NULL. On success, ID will be set to a value
      *      associated with that memory which can be used as a parameter to the other functions
      *      in SkImageCache. On failure, ID is unchanged.
      *  @return Pointer to the newly allocated memory, or NULL. This memory is safe to use until
      *      releaseCache is called with ID.
      */
@@ skipping 86 matching lines @@
      */
     virtual MemoryStatus getMemoryStatus(intptr_t ID) const = 0;
 
     /**
      *  Debug only function to clear all unpinned caches.
      */
     virtual void purgeAllUnpinnedCaches() = 0;
 #endif
 
 private:
-    typedef SkRefCnt INHERITED;
+    typedef SkDiscardableMemory::Factory INHERITED;
 };
-#endif // SkImageCache_DEFINED
+#endif  // SkImageCache_DEFINED
+