TextureCache.h revision d1ad5e62fda248c6d185cde3cb6d9f01a223066c 
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#include <utils/Vector.h>
25
26#include "Debug.h"
27#include "Texture.h"
28
29namespace android {
30namespace 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 */
52class TextureCache: public OnEntryRemoved<const SkPixelRef*, Texture*> {
53public:
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()(const SkPixelRef*& pixelRef, Texture*& texture);
63
64    /**
65     * Resets all Textures to not be marked as in use
66     */
67    void resetMarkInUse();
68
69    /**
70     * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
71     * acquired for the bitmap, false otherwise. If a Texture was acquired it is
72     * marked as in use.
73     */
74    bool prefetchAndMarkInUse(const SkBitmap* bitmap);
75
76    /**
77     * Returns the texture associated with the specified bitmap. If the texture
78     * cannot be found in the cache, a new texture is generated.
79     */
80    Texture* get(const SkBitmap* bitmap);
81    /**
82     * Returns the texture associated with the specified bitmap. The generated
83     * texture is not kept in the cache. The caller must destroy the texture.
84     */
85    Texture* getTransient(const SkBitmap* bitmap);
86    /**
87     * Removes the texture associated with the specified bitmap.
88     * Upon remove the texture is freed.
89     */
90    void remove(const SkBitmap* bitmap);
91    /**
92     * Removes the texture associated with the specified bitmap. This is meant
93     * to be called from threads that are not the EGL context thread.
94     */
95    void removeDeferred(const SkBitmap* bitmap);
96    /**
97     * Process deferred removals.
98     */
99    void clearGarbage();
100
101    /**
102     * Clears the cache. This causes all textures to be deleted.
103     */
104    void clear();
105
106    /**
107     * Sets the maximum size of the cache in bytes.
108     */
109    void setMaxSize(uint32_t maxSize);
110    /**
111     * Returns the maximum size of the cache in bytes.
112     */
113    uint32_t getMaxSize();
114    /**
115     * Returns the current size of the cache in bytes.
116     */
117    uint32_t getSize();
118
119    /**
120     * Partially flushes the cache. The amount of memory freed by a flush
121     * is defined by the flush rate.
122     */
123    void flush();
124    /**
125     * Indicates the percentage of the cache to retain when a
126     * memory trim is requested (see Caches::flush).
127     */
128    void setFlushRate(float flushRate);
129
130private:
131
132    bool canMakeTextureFromBitmap(const SkBitmap* bitmap);
133
134    Texture* getCachedTexture(const SkBitmap* bitmap);
135
136    /**
137     * Generates the texture from a bitmap into the specified texture structure.
138     *
139     * @param regenerate If true, the bitmap data is reuploaded into the texture, but
140     *        no new texture is generated.
141     */
142    void generateTexture(const SkBitmap* bitmap, Texture* texture, bool regenerate = false);
143
144    void uploadLoFiTexture(bool resize, const SkBitmap* bitmap, uint32_t width, uint32_t height);
145    void uploadToTexture(bool resize, GLenum format, GLsizei stride,
146            GLsizei width, GLsizei height, GLenum type, const GLvoid * data);
147
148    void init();
149
150    LruCache<const SkPixelRef*, Texture*> mCache;
151
152    uint32_t mSize;
153    uint32_t mMaxSize;
154    GLint mMaxTextureSize;
155
156    float mFlushRate;
157
158    bool mDebugEnabled;
159
160    Vector<const SkBitmap*> mGarbage;
161    mutable Mutex mLock;
162}; // class TextureCache
163
164}; // namespace uirenderer
165}; // namespace android
166
167#endif // ANDROID_HWUI_TEXTURE_CACHE_H
168