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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/Mutex.h>
23 #include <utils/Vector.h>
24 
25 #include "Debug.h"
26 #include "Texture.h"
27 #include "utils/GenerationCache.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     GenerationCache<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