TextureCache.h revision 00783be809c1176fa9e904b76b3d56f268dcc4da 
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
30namespace android {
31
32class Bitmap;
33
34namespace uirenderer {
35
36class Texture;
37
38///////////////////////////////////////////////////////////////////////////////
39// Defines
40///////////////////////////////////////////////////////////////////////////////
41
42// Debug
43#if DEBUG_TEXTURES
44    #define TEXTURE_LOGD(...) ALOGD(__VA_ARGS__)
45#else
46    #define TEXTURE_LOGD(...)
47#endif
48
49///////////////////////////////////////////////////////////////////////////////
50// Classes
51///////////////////////////////////////////////////////////////////////////////
52
53/**
54 * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
55 * Any texture added to the cache causing the cache to grow beyond the maximum
56 * allowed size will also cause the oldest texture to be kicked out.
57 */
58class TextureCache : public OnEntryRemoved<uint32_t, Texture*> {
59public:
60    TextureCache();
61    ~TextureCache();
62
63    /**
64     * Used as a callback when an entry is removed from the cache.
65     * Do not invoke directly.
66     */
67    void operator()(uint32_t&, Texture*& texture) override;
68
69    /**
70     * Resets all Textures to not be marked as in use
71     */
72    void resetMarkInUse(void* ownerToken);
73
74    /**
75     * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
76     * acquired for the bitmap, false otherwise. If a Texture was acquired it is
77     * marked as in use.
78     */
79    bool prefetchAndMarkInUse(void* ownerToken, Bitmap* bitmap);
80
81    /**
82     * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
83     * acquired for the bitmap, false otherwise. Does not mark the Texture
84     * as in use and won't update currently in-use Textures.
85     */
86    bool prefetch(Bitmap* bitmap);
87
88    /**
89     * Returns the texture associated with the specified bitmap from within the cache.
90     * If the texture cannot be found in the cache, a new texture is generated.
91     */
92    Texture* get(Bitmap* bitmap);
93
94    /**
95     * Removes the texture associated with the specified pixelRef. This is meant
96     * to be called from threads that are not the EGL context thread.
97     */
98    ANDROID_API void releaseTexture(uint32_t pixelRefStableID);
99    /**
100     * Process deferred removals.
101     */
102    void clearGarbage();
103
104    /**
105     * Clears the cache. This causes all textures to be deleted.
106     */
107    void clear();
108
109    /**
110     * Returns the maximum size of the cache in bytes.
111     */
112    uint32_t getMaxSize();
113    /**
114     * Returns the current size of the cache in bytes.
115     */
116    uint32_t getSize();
117
118    /**
119     * Partially flushes the cache. The amount of memory freed by a flush
120     * is defined by the flush rate.
121     */
122    void flush();
123
124private:
125    bool canMakeTextureFromBitmap(Bitmap* bitmap);
126
127    Texture* getCachedTexture(Bitmap* bitmap);
128    Texture* createTexture(Bitmap* bitmap);
129
130    LruCache<uint32_t, Texture*> mCache;
131
132    uint32_t mSize;
133    const uint32_t mMaxSize;
134    GLint mMaxTextureSize;
135
136    const float mFlushRate;
137
138    bool mDebugEnabled;
139
140    std::vector<uint32_t> mGarbage;
141    std::unordered_map<uint32_t, std::unique_ptr<Texture>> mHardwareTextures;
142    mutable Mutex mLock;
143}; // class TextureCache
144
145}; // namespace uirenderer
146}; // namespace android
147
148#endif // ANDROID_HWUI_TEXTURE_CACHE_H
149