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 <vector>
30#include <unordered_map>
31
32namespace android {
33
34class Bitmap;
35
36namespace uirenderer {
37
38class 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 */
60class TextureCache : public OnEntryRemoved<uint32_t, Texture*> {
61public:
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
122private:
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