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