/*
* Created on 09-Sep-2004
* Created by Paul Gardner
* Copyright (C) 2004, 2005, 2006 Aelitis, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* AELITIS, SAS au capital de 46,603.30 euros
* 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
*
*/
package org.gudy.azureus2.core3.util;
import java.nio.ByteBuffer;
/**
* @author parg
*
*/
public class
ConcurrentHasherRequest
{
private static AEMonitor class_mon = new AEMonitor( "ConcHashRequest:class" );
private ConcurrentHasher concurrent_hasher;
private ByteBuffer buffer;
private ConcurrentHasherRequestListener listener;
private int size;
private byte[] result;
private boolean cancelled;
private boolean low_priority;
private AESemaphore sem = new AESemaphore("ConcHashRequest");
protected
ConcurrentHasherRequest(
ConcurrentHasher _concurrent_hasher,
ByteBuffer _buffer,
ConcurrentHasherRequestListener _listener,
boolean _low_priorty )
{
concurrent_hasher = _concurrent_hasher;
buffer = _buffer;
listener = _listener;
low_priority = _low_priorty;
size = buffer.limit() - buffer.position();
}
/**
* synchronously get the result of the hash - null returned if it is cancelled
* @return
*/
public byte[]
getResult()
{
sem.reserve();
return( result );
}
/**
* cancel the hash request. If it is cancelled before it is completed then
* a subsequent call to getResult will return null
*/
public void
cancel()
{
if ( !cancelled ){
cancelled = true;
sem.releaseForever();
ConcurrentHasherRequestListener listener_copy;
try{
class_mon.enter();
listener_copy = listener;
listener = null;
}finally{
class_mon.exit();
}
if ( listener_copy != null ){
listener_copy.complete( this );
}
}
}
public boolean
getCancelled()
{
return( cancelled );
}
public int
getSize()
{
return( size );
}
public boolean
isLowPriority()
{
return( low_priority );
}
protected void
run(
SHA1Hasher hasher )
{
if ( !cancelled ){
if ( AEDiagnostics.ALWAYS_PASS_HASH_CHECKS ){
result = new byte[0];
}else{
result = hasher.calculateHash( buffer );
}
sem.releaseForever();
if ( !cancelled ){
ConcurrentHasherRequestListener listener_copy;
try{
class_mon.enter();
listener_copy = listener;
listener = null;
}finally{
class_mon.exit();
}
if ( listener_copy != null ){
listener_copy.complete( this );
}
}
}
}
}