LayerCache.h revision 2055abaa0a590c35e27e1ae2e7d7cfccdfb98b59 
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_LAYER_CACHE_H
18#define ANDROID_HWUI_LAYER_CACHE_H
19
20#include "Debug.h"
21#include "Layer.h"
22#include "Properties.h"
23#include "utils/SortedList.h"
24
25namespace android {
26namespace uirenderer {
27
28///////////////////////////////////////////////////////////////////////////////
29// Defines
30///////////////////////////////////////////////////////////////////////////////
31
32// Debug
33#if DEBUG_LAYERS
34    #define LAYER_LOGD(...) ALOGD(__VA_ARGS__)
35#else
36    #define LAYER_LOGD(...)
37#endif
38
39///////////////////////////////////////////////////////////////////////////////
40// Cache
41///////////////////////////////////////////////////////////////////////////////
42
43class LayerCache {
44public:
45    LayerCache();
46    ~LayerCache();
47
48    /**
49     * Returns a layer large enough for the specified dimensions. If no suitable
50     * layer can be found, a new one is created and returned. If creating a new
51     * layer fails, NULL is returned.
52     *
53     * When a layer is obtained from the cache, it is removed and the total
54     * size of the cache goes down.
55     *
56     * @param width The desired width of the layer
57     * @param width The desired height of the layer
58     */
59    Layer* get(const uint32_t width, const uint32_t height);
60
61    /**
62     * Adds the layer to the cache. The layer will not be added if there is
63     * not enough space available. Adding a layer can cause other layers to
64     * be removed from the cache.
65     *
66     * @param layer The layer to add to the cache
67     *
68     * @return True if the layer was added, false otherwise.
69     */
70    bool put(Layer* layer);
71    /**
72     * Clears the cache. This causes all layers to be deleted.
73     */
74    void clear();
75
76    /**
77     * Sets the maximum size of the cache in bytes.
78     */
79    void setMaxSize(uint32_t maxSize);
80    /**
81     * Returns the maximum size of the cache in bytes.
82     */
83    uint32_t getMaxSize();
84    /**
85     * Returns the current size of the cache in bytes.
86     */
87    uint32_t getSize();
88
89    /**
90     * Prints out the content of the cache.
91     */
92    void dump();
93
94    struct LayerEntry {
95        LayerEntry():
96            mLayer(NULL), mWidth(0), mHeight(0) {
97        }
98
99        LayerEntry(const uint32_t layerWidth, const uint32_t layerHeight): mLayer(NULL) {
100            mWidth = Layer::computeIdealWidth(layerWidth);
101            mHeight = Layer::computeIdealHeight(layerHeight);
102        }
103
104        LayerEntry(Layer* layer):
105            mLayer(layer), mWidth(layer->getWidth()), mHeight(layer->getHeight()) {
106        }
107
108        static int compare(const LayerEntry& lhs, const LayerEntry& rhs);
109
110        bool operator==(const LayerEntry& other) const {
111            return compare(*this, other) == 0;
112        }
113
114        bool operator!=(const LayerEntry& other) const {
115            return compare(*this, other) != 0;
116        }
117
118        Layer* mLayer;
119        uint32_t mWidth;
120        uint32_t mHeight;
121    }; // struct LayerEntry
122
123private:
124    void deleteLayer(Layer* layer);
125
126    SortedList<LayerEntry> mCache;
127
128    uint32_t mSize;
129    uint32_t mMaxSize;
130}; // class LayerCache
131
132inline int strictly_order_type(const LayerCache::LayerEntry& lhs,
133        const LayerCache::LayerEntry& rhs) {
134    return LayerCache::LayerEntry::compare(lhs, rhs) < 0;
135}
136
137inline int compare_type(const LayerCache::LayerEntry& lhs, const LayerCache::LayerEntry& rhs) {
138    return LayerCache::LayerEntry::compare(lhs, rhs);
139}
140
141}; // namespace uirenderer
142}; // namespace android
143
144#endif // ANDROID_HWUI_LAYER_CACHE_H
145