private iterator to visit all resource cache entries

src/core/SkBitmapCache.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapCache.h"
 #include "SkResourceCache.h"
 #include "SkMipMap.h"
@@ skipping 56 matching lines @@
 struct BitmapRec : public SkResourceCache::Rec {
     BitmapRec(uint32_t genID, SkScalar scaleX, SkScalar scaleY, const SkIRect& bounds,
               const SkBitmap& result)
         : fKey(genID, scaleX, scaleY, bounds)
         , fBitmap(result)
     {}
 
     const Key& getKey() const override { return fKey; }
     size_t bytesUsed() const override { return sizeof(fKey) + fBitmap.getSize(); }
 
+    const char* getCategory() const override { return "bitmap"; }
+    SkDiscardableMemory* diagnostic_only_getDiscardable() const override {
+        return fBitmap.pixelRef()->diagnostic_only_getDiscardable();
+    }
+
     static bool Finder(const SkResourceCache::Rec& baseRec, void* contextBitmap) {
         const BitmapRec& rec = static_cast<const BitmapRec&>(baseRec);
         SkBitmap* result = (SkBitmap*)contextBitmap;
 
         *result = rec.fBitmap;
         result->lockPixels();
         return SkToBool(result->getPixels());
     }
 
 private:
@@ skipping 93 matching lines @@
     {
         fMipMap->attachToCacheAndRef();
     }
 
     virtual ~MipMapRec() {
         fMipMap->detachFromCacheAndUnref();
     }
 
     const Key& getKey() const override { return fKey; }
     size_t bytesUsed() const override { return sizeof(fKey) + fMipMap->size(); }
+    const char* getCategory() const override { return "mipmap"; }
+    SkDiscardableMemory* diagnostic_only_getDiscardable() const override {
+        return fMipMap->diagnostic_only_getDiscardable();
+    }
 
     static bool Finder(const SkResourceCache::Rec& baseRec, void* contextMip) {
         const MipMapRec& rec = static_cast<const MipMapRec&>(baseRec);
         const SkMipMap* mm = SkRef(rec.fMipMap);
         // the call to ref() above triggers a "lock" in the case of discardable memory,
         // which means we can now check for null (in case the lock failed).
         if (NULL == mm->data()) {
             mm->unref();    // balance our call to ref()
             return false;
         }
@@ skipping 25 matching lines @@
 
 const SkMipMap* SkMipMapCache::AddAndRef(const SkBitmap& src, SkResourceCache* localCache) {
     SkMipMap* mipmap = SkMipMap::Build(src, get_fact(localCache));
     if (mipmap) {
         MipMapRec* rec = SkNEW_ARGS(MipMapRec, (src, mipmap));
         CHECK_LOCAL(localCache, add, Add, rec);
         src.pixelRef()->notifyAddedToCache();
     }
     return mipmap;
 }