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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 <utils/LruCache.h>
     23 #include <utils/Mutex.h>
     24 #include <utils/Vector.h>
     25 
     26 #include "Debug.h"
     27 #include "Texture.h"
     28 
     29 namespace android {
     30 namespace uirenderer {
     31 
     32 ///////////////////////////////////////////////////////////////////////////////
     33 // Defines
     34 ///////////////////////////////////////////////////////////////////////////////
     35 
     36 // Debug
     37 #if DEBUG_TEXTURES
     38     #define TEXTURE_LOGD(...) ALOGD(__VA_ARGS__)
     39 #else
     40     #define TEXTURE_LOGD(...)
     41 #endif
     42 
     43 ///////////////////////////////////////////////////////////////////////////////
     44 // Classes
     45 ///////////////////////////////////////////////////////////////////////////////
     46 
     47 /**
     48  * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
     49  * Any texture added to the cache causing the cache to grow beyond the maximum
     50  * allowed size will also cause the oldest texture to be kicked out.
     51  */
     52 class TextureCache: public OnEntryRemoved<SkBitmap*, Texture*> {
     53 public:
     54     TextureCache();
     55     TextureCache(uint32_t maxByteSize);
     56     ~TextureCache();
     57 
     58     /**
     59      * Used as a callback when an entry is removed from the cache.
     60      * Do not invoke directly.
     61      */
     62     void operator()(SkBitmap*& bitmap, Texture*& texture);
     63 
     64     /**
     65      * Returns the texture associated with the specified bitmap. If the texture
     66      * cannot be found in the cache, a new texture is generated.
     67      */
     68     Texture* get(SkBitmap* bitmap);
     69     /**
     70      * Returns the texture associated with the specified bitmap. The generated
     71      * texture is not kept in the cache. The caller must destroy the texture.
     72      */
     73     Texture* getTransient(SkBitmap* bitmap);
     74     /**
     75      * Removes the texture associated with the specified bitmap.
     76      * Upon remove the texture is freed.
     77      */
     78     void remove(SkBitmap* bitmap);
     79     /**
     80      * Removes the texture associated with the specified bitmap. This is meant
     81      * to be called from threads that are not the EGL context thread.
     82      */
     83     void removeDeferred(SkBitmap* bitmap);
     84     /**
     85      * Process deferred removals.
     86      */
     87     void clearGarbage();
     88 
     89     /**
     90      * Clears the cache. This causes all textures to be deleted.
     91      */
     92     void clear();
     93 
     94     /**
     95      * Sets the maximum size of the cache in bytes.
     96      */
     97     void setMaxSize(uint32_t maxSize);
     98     /**
     99      * Returns the maximum size of the cache in bytes.
    100      */
    101     uint32_t getMaxSize();
    102     /**
    103      * Returns the current size of the cache in bytes.
    104      */
    105     uint32_t getSize();
    106 
    107     /**
    108      * Partially flushes the cache. The amount of memory freed by a flush
    109      * is defined by the flush rate.
    110      */
    111     void flush();
    112     /**
    113      * Indicates the percentage of the cache to retain when a
    114      * memory trim is requested (see Caches::flush).
    115      */
    116     void setFlushRate(float flushRate);
    117 
    118 private:
    119     /**
    120      * Generates the texture from a bitmap into the specified texture structure.
    121      *
    122      * @param regenerate If true, the bitmap data is reuploaded into the texture, but
    123      *        no new texture is generated.
    124      */
    125     void generateTexture(SkBitmap* bitmap, Texture* texture, bool regenerate = false);
    126 
    127     void uploadLoFiTexture(bool resize, SkBitmap* bitmap, uint32_t width, uint32_t height);
    128     void uploadToTexture(bool resize, GLenum format, GLsizei width, GLsizei height,
    129             GLenum type, const GLvoid * data);
    130 
    131     void init();
    132 
    133     LruCache<SkBitmap*, Texture*> mCache;
    134 
    135     uint32_t mSize;
    136     uint32_t mMaxSize;
    137     GLint mMaxTextureSize;
    138 
    139     float mFlushRate;
    140 
    141     bool mDebugEnabled;
    142 
    143     Vector<SkBitmap*> mGarbage;
    144     mutable Mutex mLock;
    145 }; // class TextureCache
    146 
    147 }; // namespace uirenderer
    148 }; // namespace android
    149 
    150 #endif // ANDROID_HWUI_TEXTURE_CACHE_H
    151