/*
* Copyright 2004-2011 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.store.fs;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
/**
* Allows to read from a file channel like an input stream.
*/
public class FileChannelInputStream extends InputStream {
private FileChannel channel;
private byte[] buffer = { 0 };
/**
* Create a new file object input stream from the file channel.
*
* @param channel the file channel
*/
public FileChannelInputStream(FileChannel channel) {
this.channel = channel;
}
public int read() throws IOException {
if (channel.position() >= channel.size()) {
return -1;
}
FileUtils.readFully(channel, ByteBuffer.wrap(buffer));
return buffer[0] & 0xff;
}
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
public int read(byte[] b, int off, int len) throws IOException {
if (channel.position() + len < channel.size()) {
FileUtils.readFully(channel, ByteBuffer.wrap(b, off, len));
return len;
}
return super.read(b, off, len);
}
public void close() throws IOException {
channel.close();
}
}