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 
25 #include "Debug.h"
26 
27 #include <vector>
28 #include <unordered_map>
29 
30 namespace android {
31 namespace uirenderer {
32 
33 class Texture;
34 
35 ///////////////////////////////////////////////////////////////////////////////
36 // Defines
37 ///////////////////////////////////////////////////////////////////////////////
38 
39 // Debug
40 #if DEBUG_TEXTURES
41     #define TEXTURE_LOGD(...) ALOGD(__VA_ARGS__)
42 #else
43     #define TEXTURE_LOGD(...)
44 #endif
45 
46 ///////////////////////////////////////////////////////////////////////////////
47 // Classes
48 ///////////////////////////////////////////////////////////////////////////////
49 
50 class AssetAtlas;
51 
52 /**
53  * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
54  * Any texture added to the cache causing the cache to grow beyond the maximum
55  * allowed size will also cause the oldest texture to be kicked out.
56  */
57 class TextureCache : public OnEntryRemoved<uint32_t, Texture*> {
58 public:
59     TextureCache();
60     ~TextureCache();
61 
62     /**
63      * Used as a callback when an entry is removed from the cache.
64      * Do not invoke directly.
65      */
66     void operator()(uint32_t&, Texture*& texture) override;
67 
68     /**
69      * Resets all Textures to not be marked as in use
70      */
71     void resetMarkInUse(void* ownerToken);
72 
73     /**
74      * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
75      * acquired for the bitmap, false otherwise. If a Texture was acquired it is
76      * marked as in use.
77      */
78     bool prefetchAndMarkInUse(void* ownerToken, const SkBitmap* bitmap);
79 
80     /**
81      * Returns the texture associated with the specified bitmap from either within the cache, or
82      * the AssetAtlas. If the texture cannot be found in the cache, a new texture is generated.
83      */
get(const SkBitmap * bitmap)84     Texture* get(const SkBitmap* bitmap) {
85         return get(bitmap, AtlasUsageType::Use);
86     }
87 
88     /**
89      * Returns the texture associated with the specified bitmap. If the texture cannot be found in
90      * the cache, a new texture is generated, even if it resides in the AssetAtlas.
91      */
getAndBypassAtlas(const SkBitmap * bitmap)92     Texture* getAndBypassAtlas(const SkBitmap* bitmap) {
93         return get(bitmap, AtlasUsageType::Bypass);
94     }
95 
96     /**
97      * Removes the texture associated with the specified pixelRef. This is meant
98      * to be called from threads that are not the EGL context thread.
99      */
100     ANDROID_API void releaseTexture(uint32_t pixelRefStableID);
101     /**
102      * Process deferred removals.
103      */
104     void clearGarbage();
105 
106     /**
107      * Clears the cache. This causes all textures to be deleted.
108      */
109     void clear();
110 
111     /**
112      * Returns the maximum size of the cache in bytes.
113      */
114     uint32_t getMaxSize();
115     /**
116      * Returns the current size of the cache in bytes.
117      */
118     uint32_t getSize();
119 
120     /**
121      * Partially flushes the cache. The amount of memory freed by a flush
122      * is defined by the flush rate.
123      */
124     void flush();
125 
126     void setAssetAtlas(AssetAtlas* assetAtlas);
127 
128 private:
129     enum class AtlasUsageType {
130         Use,
131         Bypass,
132     };
133 
134     bool canMakeTextureFromBitmap(const SkBitmap* bitmap);
135 
136     Texture* get(const SkBitmap* bitmap, AtlasUsageType atlasUsageType);
137     Texture* getCachedTexture(const SkBitmap* bitmap, AtlasUsageType atlasUsageType);
138 
139     LruCache<uint32_t, Texture*> mCache;
140 
141     uint32_t mSize;
142     const uint32_t mMaxSize;
143     GLint mMaxTextureSize;
144 
145     const float mFlushRate;
146 
147     bool mDebugEnabled;
148 
149     std::vector<uint32_t> mGarbage;
150     mutable Mutex mLock;
151 
152     AssetAtlas* mAssetAtlas;
153 }; // class TextureCache
154 
155 }; // namespace uirenderer
156 }; // namespace android
157 
158 #endif // ANDROID_HWUI_TEXTURE_CACHE_H
159