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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_HWUI_TEXTURE_CACHE_H
     18 #define ANDROID_HWUI_TEXTURE_CACHE_H
     19 
     20 #include <SkBitmap.h>
     21 
     22 #include <cutils/compiler.h>
     23 
     24 #include <utils/LruCache.h>
     25 #include <utils/Mutex.h>
     26 
     27 #include "Debug.h"
     28 
     29 #include <unordered_map>
     30 #include <vector>
     31 
     32 namespace android {
     33 
     34 class Bitmap;
     35 
     36 namespace uirenderer {
     37 
     38 class Texture;
     39 
     40 ///////////////////////////////////////////////////////////////////////////////
     41 // Defines
     42 ///////////////////////////////////////////////////////////////////////////////
     43 
     44 // Debug
     45 #if DEBUG_TEXTURES
     46 #define TEXTURE_LOGD(...) ALOGD(__VA_ARGS__)
     47 #else
     48 #define TEXTURE_LOGD(...)
     49 #endif
     50 
     51 ///////////////////////////////////////////////////////////////////////////////
     52 // Classes
     53 ///////////////////////////////////////////////////////////////////////////////
     54 
     55 /**
     56  * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
     57  * Any texture added to the cache causing the cache to grow beyond the maximum
     58  * allowed size will also cause the oldest texture to be kicked out.
     59  */
     60 class TextureCache : public OnEntryRemoved<uint32_t, Texture*> {
     61 public:
     62     TextureCache();
     63     ~TextureCache();
     64 
     65     /**
     66      * Used as a callback when an entry is removed from the cache.
     67      * Do not invoke directly.
     68      */
     69     void operator()(uint32_t&, Texture*& texture) override;
     70 
     71     /**
     72      * Resets all Textures to not be marked as in use
     73      */
     74     void resetMarkInUse(void* ownerToken);
     75 
     76     /**
     77      * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
     78      * acquired for the bitmap, false otherwise. If a Texture was acquired it is
     79      * marked as in use.
     80      */
     81     bool prefetchAndMarkInUse(void* ownerToken, Bitmap* bitmap);
     82 
     83     /**
     84      * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
     85      * acquired for the bitmap, false otherwise. Does not mark the Texture
     86      * as in use and won't update currently in-use Textures.
     87      */
     88     bool prefetch(Bitmap* bitmap);
     89 
     90     /**
     91      * Returns the texture associated with the specified bitmap from within the cache.
     92      * If the texture cannot be found in the cache, a new texture is generated.
     93      */
     94     Texture* get(Bitmap* bitmap);
     95 
     96     /**
     97      * Removes the texture associated with the specified pixelRef. Must be called from RenderThread
     98      * Returns true if a texture was destroyed, false if no texture with that id was found
     99      */
    100     bool destroyTexture(uint32_t pixelRefStableID);
    101 
    102     /**
    103      * Clears the cache. This causes all textures to be deleted.
    104      */
    105     void clear();
    106 
    107     /**
    108      * Returns the maximum size of the cache in bytes.
    109      */
    110     uint32_t getMaxSize();
    111     /**
    112      * Returns the current size of the cache in bytes.
    113      */
    114     uint32_t getSize();
    115 
    116     /**
    117      * Partially flushes the cache. The amount of memory freed by a flush
    118      * is defined by the flush rate.
    119      */
    120     void flush();
    121 
    122 private:
    123     bool canMakeTextureFromBitmap(Bitmap* bitmap);
    124 
    125     Texture* getCachedTexture(Bitmap* bitmap);
    126     Texture* createTexture(Bitmap* bitmap);
    127 
    128     LruCache<uint32_t, Texture*> mCache;
    129 
    130     uint32_t mSize;
    131     const uint32_t mMaxSize;
    132     GLint mMaxTextureSize;
    133 
    134     const float mFlushRate;
    135 
    136     bool mDebugEnabled;
    137 
    138     std::unordered_map<uint32_t, std::unique_ptr<Texture>> mHardwareTextures;
    139 };  // class TextureCache
    140 
    141 };  // namespace uirenderer
    142 };  // namespace android
    143 
    144 #endif  // ANDROID_HWUI_TEXTURE_CACHE_H
    145