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