package org.apache.archiva.common.filelock;
/*
* 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.
*/
import java.io.Closeable;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
/**
* @author Olivier Lamy
* @since 2.0.0
*/
public class Lock
{
private File file;
private AtomicBoolean write;
private final Map<Thread, AtomicInteger> fileClients = new HashMap<>();
private FileLock fileLock;
private RandomAccessFile randomAccessFile;
private FileChannel fileChannel;
public Lock( File file )
{
this.file = file;
}
public Lock( File file, boolean write )
throws FileNotFoundException
{
this.file = file;
this.write = new AtomicBoolean( write );
randomAccessFile = new RandomAccessFile( file, write ? "rw" : "r" );
fileChannel = randomAccessFile.getChannel();
}
public File getFile()
{
return file;
}
public AtomicBoolean isWrite()
{
return write;
}
public void setFile( File file )
{
this.file = file;
}
public void setWrite( boolean write )
{
this.write.set( write );
}
public boolean isShared()
{
return this.fileLock.isValid() && this.fileLock.isShared();
}
public boolean isValid()
{
return this.fileLock!=null && this.fileLock.isValid();
}
public Map<Thread, AtomicInteger> getFileClients()
{
return fileClients;
}
public void addFileClient( Thread thread )
{
this.fileClients.put( thread, new AtomicInteger( 1 ) );
}
public boolean removeFileClient( Thread thread )
{
return this.fileClients.remove( thread ) != null;
}
protected void close()
throws IOException
{
IOException ioException = null;
try
{
this.fileLock.release();
}
catch ( IOException e )
{
ioException = e;
}
closeQuietly( fileChannel );
closeQuietly( randomAccessFile );
fileClients.remove( Thread.currentThread() );
if ( ioException != null )
{
throw ioException;
}
}
protected void openLock( boolean write, boolean timeout )
throws IOException
{
fileClients.put( Thread.currentThread(), new AtomicInteger( 1 ) );
this.fileLock = timeout
? fileChannel.tryLock( 0L, Long.MAX_VALUE, write ? false : true )
: fileChannel.lock( 0L, Long.MAX_VALUE, write ? false : true );
}
protected RandomAccessFile getRandomAccessFile()
{
return randomAccessFile;
}
private void closeQuietly( Closeable closeable )
{
try
{
closeable.close();
}
catch ( IOException e )
{
// ignore
}
}
@Override
public String toString()
{
final StringBuilder sb = new StringBuilder( "Lock{" );
sb.append( "file=" ).append( file );
sb.append( '}' );
return sb.toString();
}
}