blob: a3d470b01cd38e1f4c8bc5536c79582002374027 (
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
|
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 javax.imageio.stream;
import org.apache.harmony.x.imageio.stream.RandomAccessMemoryCache;
import java.io.IOException;
import java.io.InputStream;
/**
* The MemoryCacheImageInputStream class implements ImageInputStream
* using a memory buffer for caching the data.
*/
public class MemoryCacheImageInputStream extends ImageInputStreamImpl {
/** The is. */
private InputStream is;
/** The ramc. */
private RandomAccessMemoryCache ramc = new RandomAccessMemoryCache();
/**
* Instantiates a new MemoryCacheImageInputStream
* which reads from the specified InputStream.
*
* @param stream the InputStream to be read.
*/
public MemoryCacheImageInputStream(InputStream stream) {
if (stream == null) {
throw new IllegalArgumentException("stream == null!");
}
is = stream;
}
@Override
public int read() throws IOException {
bitOffset = 0;
if (streamPos >= ramc.length()) {
int count = (int)(streamPos - ramc.length() + 1);
int bytesAppended = ramc.appendData(is, count);
if (bytesAppended < count) {
return -1;
}
}
int res = ramc.getData(streamPos);
if (res >= 0) {
streamPos++;
}
return res;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
bitOffset = 0;
if (streamPos >= ramc.length()) {
int count = (int)(streamPos - ramc.length() + len);
ramc.appendData(is, count);
}
int res = ramc.getData(b, off, len, streamPos);
if (res > 0) {
streamPos += res;
}
return res;
}
@Override
public boolean isCached() {
return true;
}
@Override
public boolean isCachedFile() {
return false;
}
@Override
public boolean isCachedMemory() {
return true;
}
@Override
public void close() throws IOException {
super.close();
ramc.close();
}
@Override
public void flushBefore(long pos) throws IOException {
super.flushBefore(pos);
ramc.freeBefore(getFlushedPosition());
}
}
|
