120 lines
3.1 KiB
Java
120 lines
3.1 KiB
Java
/*
|
|
* 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.
|
|
*
|
|
* @since Android 1.0
|
|
*/
|
|
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());
|
|
}
|
|
}
|