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 "utils/SortedList.h"
23 
24 namespace android {
25 namespace uirenderer {
26 
27 class RenderState;
28 
29 ///////////////////////////////////////////////////////////////////////////////
30 // Defines
31 ///////////////////////////////////////////////////////////////////////////////
32 
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 
43 class LayerCache {
44 public:
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 height The desired height of the layer
58      */
59     Layer* get(RenderState& renderState, 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     size_t getCount();
90 
91     /**
92      * Prints out the content of the cache.
93      */
94     void dump();
95 
96 private:
97     struct LayerEntry {
LayerEntryLayerEntry98         LayerEntry():
99             mLayer(nullptr), mWidth(0), mHeight(0) {
100         }
101 
LayerEntryLayerEntry102         LayerEntry(const uint32_t layerWidth, const uint32_t layerHeight): mLayer(nullptr) {
103             mWidth = Layer::computeIdealWidth(layerWidth);
104             mHeight = Layer::computeIdealHeight(layerHeight);
105         }
106 
LayerEntryLayerEntry107         LayerEntry(Layer* layer):
108             mLayer(layer), mWidth(layer->getWidth()), mHeight(layer->getHeight()) {
109         }
110 
111         static int compare(const LayerEntry& lhs, const LayerEntry& rhs);
112 
113         bool operator==(const LayerEntry& other) const {
114             return compare(*this, other) == 0;
115         }
116 
117         bool operator!=(const LayerEntry& other) const {
118             return compare(*this, other) != 0;
119         }
120 
strictly_order_typeLayerEntry121         friend inline int strictly_order_type(const LayerEntry& lhs, const LayerEntry& rhs) {
122             return LayerEntry::compare(lhs, rhs) < 0;
123         }
124 
compare_typeLayerEntry125         friend inline int compare_type(const LayerEntry& lhs, const LayerEntry& rhs) {
126             return LayerEntry::compare(lhs, rhs);
127         }
128 
129         Layer* mLayer;
130         uint32_t mWidth;
131         uint32_t mHeight;
132     }; // struct LayerEntry
133 
134     void deleteLayer(Layer* layer);
135 
136     SortedList<LayerEntry> mCache;
137 
138     uint32_t mSize;
139     uint32_t mMaxSize;
140 }; // class LayerCache
141 
142 }; // namespace uirenderer
143 }; // namespace android
144 
145 #endif // ANDROID_HWUI_LAYER_CACHE_H
146