org.h2.store.fs.FileBaseDefault Maven / Gradle / Ivy
/*
* Copyright 2004-2022 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.store.fs;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
/**
* Default implementation of the slow operations that need synchronization because they
* involve the file position.
*/
public abstract class FileBaseDefault extends FileBase {
private long position = 0;
@Override
public final synchronized long position() throws IOException {
return position;
}
@Override
public final synchronized FileChannel position(long newPosition) throws IOException {
if (newPosition < 0) {
throw new IllegalArgumentException();
}
position = newPosition;
return this;
}
@Override
public final synchronized int read(ByteBuffer dst) throws IOException {
int read = read(dst, position);
if (read > 0) {
position += read;
}
return read;
}
@Override
public final synchronized int write(ByteBuffer src) throws IOException {
int written = write(src, position);
if (written > 0) {
position += written;
}
return written;
}
@Override
public final synchronized FileChannel truncate(long newLength) throws IOException {
implTruncate(newLength);
if (newLength < position) {
position = newLength;
}
return this;
}
/**
* The truncate implementation.
*
* @param size the new size
* @throws IOException on failure
*/
protected abstract void implTruncate(long size) throws IOException;
}