Track the size in memory of the texture cache.
The texture cache was previously checking the number of stored textures. This was
not very useful as this could easily lead to an abuse of memory. The new cache
instead tracks the total size occupied in RAM by the cached textures. When a new
texture is generated, older textures are kicked out as needed.
Change-Id: Ib27142f4a018d5bf84774c1fb6f45a67a85f20bc
diff --git a/libs/hwui/TextureCache.h b/libs/hwui/TextureCache.h
index bf68061..c974b65 100644
--- a/libs/hwui/TextureCache.h
+++ b/libs/hwui/TextureCache.h
@@ -25,21 +25,63 @@
namespace android {
namespace uirenderer {
+/**
+ * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
+ * Any texture added to the cache causing the cache to grow beyond the maximum
+ * allowed size will also cause the oldest texture to be kicked out.
+ */
class TextureCache: public OnEntryRemoved<SkBitmap*, Texture*> {
public:
- TextureCache(unsigned int maxEntries);
+ TextureCache(unsigned int maxByteSize);
~TextureCache();
- void operator()(SkBitmap* key, Texture* value);
+ /**
+ * Used as a callback when an entry is removed from the cache.
+ * Do not invoke directly.
+ */
+ void operator()(SkBitmap* bitmap, Texture* texture);
+ /**
+ * Returns the texture associated with the specified bitmap. If the texture
+ * cannot be found in the cache, a new texture is generated.
+ */
Texture* get(SkBitmap* bitmap);
- Texture* remove(SkBitmap* bitmap);
+ /**
+ * Removes the texture associated with the specified bitmap. Returns NULL
+ * if the texture cannot be found. Upon remove the texture is freed.
+ */
+ void remove(SkBitmap* bitmap);
+ /**
+ * Clears the cache. This causes all textures to be deleted.
+ */
void clear();
+ /**
+ * Sets the maximum size of the cache in bytes.
+ */
+ void setMaxSize(unsigned int maxSize);
+ /**
+ * Returns the maximum size of the cache in bytes.
+ */
+ unsigned int getMaxSize();
+ /**
+ * Returns the current size of the cache in bytes.
+ */
+ unsigned int getSize();
+
private:
+ /**
+ * Generates the texture from a bitmap into the specified texture structure.
+ *
+ * @param regenerate If true, the bitmap data is reuploaded into the texture, but
+ * no new texture is generated.
+ */
void generateTexture(SkBitmap* bitmap, Texture* texture, bool regenerate = false);
GenerationCache<SkBitmap, Texture> mCache;
+
+ unsigned int mSize;
+ unsigned int mMaxSize;
}; // class TextureCache
}; // namespace uirenderer