summaryrefslogtreecommitdiffstats
path: root/src/com/android/photos/data/SparseArrayBitmapPool.java
blob: 85125905673e4d0a233539c8c1edb366c103849f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.photos.data;

import android.graphics.Bitmap;
import android.util.SparseArray;

import android.util.Pools.Pool;

public class SparseArrayBitmapPool {

    private static final int BITMAPS_TO_KEEP_AFTER_UNNEEDED_HINT = 4;
    private int mCapacityBytes;
    private SparseArray<Node> mStore = new SparseArray<Node>();
    private int mSizeBytes = 0;

    private Pool<Node> mNodePool;
    private Node mPoolNodesHead = null;
    private Node mPoolNodesTail = null;

    protected static class Node {
        Bitmap bitmap;
        Node prevInBucket;
        Node nextInBucket;
        Node nextInPool;
        Node prevInPool;
    }

    public SparseArrayBitmapPool(int capacityBytes, Pool<Node> nodePool) {
        mCapacityBytes = capacityBytes;
        mNodePool = nodePool;
    }

    public synchronized void setCapacity(int capacityBytes) {
        mCapacityBytes = capacityBytes;
        freeUpCapacity(0);
    }

    private void freeUpCapacity(int bytesNeeded) {
        int targetSize = mCapacityBytes - bytesNeeded;
        while (mPoolNodesTail != null && mSizeBytes > targetSize) {
            unlinkAndRecycleNode(mPoolNodesTail, true);
        }
    }

    private void unlinkAndRecycleNode(Node n, boolean recycleBitmap) {
        // Remove the node from its spot in its bucket
        if (n.prevInBucket != null) {
            n.prevInBucket.nextInBucket = n.nextInBucket;
        } else {
            mStore.put(n.bitmap.getWidth(), n.nextInBucket);
        }
        if (n.nextInBucket != null) {
            n.nextInBucket.prevInBucket = n.prevInBucket;
        }

        // Remove the node from its spot in the list of pool nodes
        if (n.prevInPool != null) {
            n.prevInPool.nextInPool = n.nextInPool;
        } else {
            mPoolNodesHead = n.nextInPool;
        }
        if (n.nextInPool != null) {
            n.nextInPool.prevInPool = n.prevInPool;
        } else {
            mPoolNodesTail = n.prevInPool;
        }

        // Recycle the node
        n.nextInBucket = null;
        n.nextInPool = null;
        n.prevInBucket = null;
        n.prevInPool = null;
        mSizeBytes -= n.bitmap.getByteCount();
        if (recycleBitmap) n.bitmap.recycle();
        n.bitmap = null;
        mNodePool.release(n);
    }

    public synchronized int getCapacity() {
        return mCapacityBytes;
    }

    public synchronized int getSize() {
        return mSizeBytes;
    }

    public synchronized Bitmap get(int width, int height) {
        Node cur = mStore.get(width);
        while (cur != null) {
            if (cur.bitmap.getHeight() == height) {
                Bitmap b = cur.bitmap;
                unlinkAndRecycleNode(cur, false);
                return b;
            }
            cur = cur.nextInBucket;
        }
        return null;
    }

    public synchronized boolean put(Bitmap b) {
        if (b == null) {
            return false;
        }
        int bytes = b.getByteCount();
        freeUpCapacity(bytes);
        Node newNode = mNodePool.acquire();
        if (newNode == null) {
            newNode = new Node();
        }
        newNode.bitmap = b;
        newNode.prevInBucket = null;
        newNode.prevInPool = null;
        newNode.nextInPool = mPoolNodesHead;
        mPoolNodesHead = newNode;
        int key = b.getWidth();
        newNode.nextInBucket = mStore.get(key);
        if (newNode.nextInBucket != null) {
            newNode.nextInBucket.prevInBucket = newNode;
        }
        mStore.put(key, newNode);
        if (newNode.nextInPool == null) {
            mPoolNodesTail = newNode;
        }
        mSizeBytes += bytes;
        return true;
    }

    public synchronized void clear() {
        freeUpCapacity(mCapacityBytes);
    }
}