/*
* 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.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.channels.NonWritableChannelException;
/**
* This file system stores files on disk and uses java.nio to access the files.
* This class uses FileChannel.
*/
public class FilePathNio extends FilePathWrapper {
public FileChannel open(String mode) throws IOException {
return new FileNio(name.substring(getScheme().length() + 1), mode);
}
public String getScheme() {
return "nio";
}
}
/**
* File which uses NIO FileChannel.
*/
class FileNio extends FileBase {
private final String name;
private final FileChannel channel;
FileNio(String fileName, String mode) throws IOException {
this.name = fileName;
channel = new RandomAccessFile(fileName, mode).getChannel();
}
public void implCloseChannel() throws IOException {
channel.close();
}
public long position() throws IOException {
return channel.position();
}
public long size() throws IOException {
return channel.size();
}
public int read(ByteBuffer dst) throws IOException {
return channel.read(dst);
}
public FileChannel position(long pos) throws IOException {
channel.position(pos);
return this;
}
public FileChannel truncate(long newLength) throws IOException {
try {
channel.truncate(newLength);
if (channel.position() > newLength) {
// looks like a bug in this FileChannel implementation, as the
// documentation says the position needs to be changed
channel.position(newLength);
}
return this;
} catch (NonWritableChannelException e) {
throw new IOException("read only");
}
}
public void force(boolean metaData) throws IOException {
channel.force(metaData);
}
public int write(ByteBuffer src) throws IOException {
try {
return channel.write(src);
} catch (NonWritableChannelException e) {
throw new IOException("read only");
}
}
public synchronized FileLock tryLock(long position, long size, boolean shared) throws IOException {
return channel.tryLock();
}
public String toString() {
return "nio:" + name;
}
}