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

1 files changed, 60 insertions, 9 deletions

diff --git a/libs/hwui/TextureCache.cpp b/libs/hwui/TextureCache.cpp
index 7b8b31398188..10e4f9e5df53 100644
--- a/libs/hwui/TextureCache.cpp
+++ b/libs/hwui/TextureCache.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define LOG_TAG "OpenGLRenderer"
+
 #include <GLES2/gl2.h>
 
 #include "TextureCache.h"
@@ -21,7 +23,13 @@
 namespace android {
 namespace uirenderer {
 
-TextureCache::TextureCache(unsigned int maxEntries): mCache(maxEntries) {
+///////////////////////////////////////////////////////////////////////////////
+// Constructors/destructor
+///////////////////////////////////////////////////////////////////////////////
+
+TextureCache::TextureCache(unsigned int maxByteSize):
+        mCache(GenerationCache<SkBitmap, Texture>::kUnlimitedCapacity),
+        mSize(0), mMaxSize(maxByteSize) {
     mCache.setOnEntryRemovedListener(this);
 }
 
@@ -29,28 +37,71 @@ TextureCache::~TextureCache() {
     mCache.clear();
 }
 
-void TextureCache::operator()(SkBitmap* key, Texture* value) {
-    LOGD("Entry removed");
-    if (value) {
-        glDeleteTextures(1, &value->id);
-        delete value;
+///////////////////////////////////////////////////////////////////////////////
+// Size management
+///////////////////////////////////////////////////////////////////////////////
+
+unsigned int TextureCache::getSize() {
+    return mSize;
+}
+
+unsigned int TextureCache::getMaxSize() {
+    return mMaxSize;
+}
+
+void TextureCache::setMaxSize(unsigned int maxSize) {
+    mMaxSize = maxSize;
+    while (mSize > mMaxSize) {
+        mCache.removeOldest();
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Callbacks
+///////////////////////////////////////////////////////////////////////////////
+
+void TextureCache::operator()(SkBitmap* bitmap, Texture* texture) {
+    if (bitmap) {
+        const unsigned int size = bitmap->rowBytes() * bitmap->height();
+        mSize -= size;
+    }
+
+    if (texture) {
+        glDeleteTextures(1, &texture->id);
+        delete texture;
     }
 }
 
+///////////////////////////////////////////////////////////////////////////////
+// Caching
+///////////////////////////////////////////////////////////////////////////////
+
 Texture* TextureCache::get(SkBitmap* bitmap) {
     Texture* texture = mCache.get(bitmap);
     if (!texture) {
+        const unsigned int size = bitmap->rowBytes() * bitmap->height();
+        // Don't even try to cache a bitmap that's bigger than the cache
+        if (size < mMaxSize) {
+            while (mSize + size > mMaxSize) {
+                mCache.removeOldest();
+            }
+        }
+
         texture = new Texture;
         generateTexture(bitmap, texture, false);
-        mCache.put(bitmap, texture);
+
+        if (size < mMaxSize) {
+            mSize += size;
+            mCache.put(bitmap, texture);
+        }
     } else if (bitmap->getGenerationID() != texture->generation) {
         generateTexture(bitmap, texture, true);
     }
     return texture;
 }
 
-Texture* TextureCache::remove(SkBitmap* bitmap) {
-    return mCache.remove(bitmap);
+void TextureCache::remove(SkBitmap* bitmap) {
+    mCache.remove(bitmap);
 }
 
 void TextureCache::clear() {