/*
* 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 org.jclouds.netty.io;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.handler.stream.ChunkedFile;
/**
*
*
*
*
* @author Tibor Kiss
*/
public class ChunkedFileInputStream extends InputStream {
private static final int CHUNK_SIZE = 8192;
private ChunkedFile chunks;
private ChannelBuffer chunk;
private IOException ex;
public ChunkedFileInputStream(String filename, long offset, long length) {
this(new File(filename), offset, length);
}
public ChunkedFileInputStream(File file, long offset, long length) {
try {
this.chunks = new ChunkedFile(new RandomAccessFile(file, "r"), offset, length, CHUNK_SIZE);
} catch (IOException ex) {
this.ex = ex;
}
}
private ChannelBuffer getChunk() throws Exception {
if (ex != null) {
throw ex;
}
if (chunk == null) {
chunk = ChannelBuffer.class.cast(chunks.nextChunk());
}
if (chunk != null) {
if (chunk.readableBytes() < 1 && chunks.hasNextChunk()) {
chunk = ChannelBuffer.class.cast(chunks.nextChunk());
if (chunk.readableBytes() < 1) {
return null;
}
}
} else {
return null;
}
return chunk;
}
@Override
public int read() throws IOException {
try {
ChannelBuffer chunk = getChunk();
if (chunk == null)
return -1;
if (chunk.readableBytes() < 1)
return -1;
int readIndex = chunk.readerIndex();
byte abyte = chunk.getByte(readIndex);
chunk.readerIndex(readIndex + 1);
return (int) abyte;
} catch (Exception e) {
throw new IOException(e);
}
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
try {
ChannelBuffer chunk = getChunk();
if (chunk == null)
return -1;
int readable = chunk.readableBytes();
if (readable < 1)
return -1;
if (readable > len) {
readable = len;
}
int readIndex = chunk.readerIndex();
chunk.getBytes(readIndex, b, off, readable);
chunk.readerIndex(readIndex + readable);
return readable;
} catch (Exception e) {
throw new IOException(e);
}
}
@Override
public void close() throws IOException {
try {
chunks.close();
} catch (Exception e) {
throw new IOException(e);
}
}
}