1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17
18package javax.imageio.stream;
19
20import org.apache.harmony.x.imageio.stream.RandomAccessMemoryCache;
21
22import java.io.OutputStream;
23import java.io.IOException;
24
25/**
26 * The MemoryCacheImageOutputStream class implements ImageOutputStream using a
27 * memory buffer for caching the data.
28 *
29 * @since Android 1.0
30 */
31public class MemoryCacheImageOutputStream extends ImageOutputStreamImpl {
32
33    /**
34     * The os.
35     */
36    OutputStream os;
37
38    /**
39     * The ramc.
40     */
41    RandomAccessMemoryCache ramc = new RandomAccessMemoryCache();
42
43    /**
44     * Instantiates a new MemoryCacheImageOutputStream which writes to the
45     * specified OutputStream.
46     *
47     * @param stream
48     *            the OutputStream.
49     */
50    public MemoryCacheImageOutputStream(OutputStream stream) {
51        if (stream == null) {
52            throw new IllegalArgumentException("stream == null!");
53        }
54        os = stream;
55    }
56
57    @Override
58    public void write(int b) throws IOException {
59        flushBits(); // See the flushBits method description
60
61        ramc.putData(b, streamPos);
62        streamPos++;
63    }
64
65    @Override
66    public void write(byte[] b, int off, int len) throws IOException {
67        flushBits(); // See the flushBits method description
68
69        ramc.putData(b, off, len, streamPos);
70        streamPos += len;
71    }
72
73    @Override
74    public int read() throws IOException {
75        bitOffset = 0;
76
77        int res = ramc.getData(streamPos);
78        if (res >= 0) {
79            streamPos++;
80        }
81        return res;
82    }
83
84    @Override
85    public int read(byte[] b, int off, int len) throws IOException {
86        bitOffset = 0;
87
88        int res = ramc.getData(b, off, len, streamPos);
89        if (res > 0) {
90            streamPos += res;
91        }
92        return res;
93    }
94
95    @Override
96    public long length() {
97        return ramc.length();
98    }
99
100    @Override
101    public boolean isCached() {
102        return true;
103    }
104
105    @Override
106    public boolean isCachedMemory() {
107        return true;
108    }
109
110    @Override
111    public boolean isCachedFile() {
112        return false;
113    }
114
115    @Override
116    public void close() throws IOException {
117        flushBefore(length());
118        super.close();
119        ramc.close();
120    }
121
122    @Override
123    public void flushBefore(long pos) throws IOException {
124        long flushedPosition = getFlushedPosition();
125        super.flushBefore(pos);
126
127        long newFlushedPosition = getFlushedPosition();
128        int nBytes = (int)(newFlushedPosition - flushedPosition);
129
130        ramc.getData(os, nBytes, flushedPosition);
131        ramc.freeBefore(newFlushedPosition);
132
133        os.flush();
134    }
135}
136