/*******************************************************************************
* Copyright (c) 2009 Eucalyptus Systems, Inc.
*
* 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, only version 3 of the License.
*
*
* This file 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, see <http://www.gnu.org/licenses/>.
*
* Please contact Eucalyptus Systems, Inc., 130 Castilian
* Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/>
* if you need additional information or have any questions.
*
* This file may incorporate work covered under the following copyright and
* permission notice:
*
* Software License Agreement (BSD License)
*
* Copyright (c) 2008, Regents of the University of California
* All rights reserved.
*
* Redistribution and use of this software in source and binary forms, with
* or without modification, are permitted provided that the following
* conditions are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. USERS OF
* THIS SOFTWARE ACKNOWLEDGE THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE
* LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS
* SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
* IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA
* BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
* THE REGENTS’ DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT
* OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO IDENTIFIED, OR
* WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT NEEDED TO COMPLY WITH
* ANY SUCH LICENSES OR RIGHTS.
*******************************************************************************
* @author chris grzegorczyk <grze@eucalyptus.com>
*/
package com.eucalyptus.util.async;
import com.google.common.base.Predicate;
import edu.ucsb.eucalyptus.msgs.BaseMessage;
public interface Callback<R> {
/**
* The operation completed. Guaranteed to be called only once per corresponding dispatch.
*
* @param t
*/
public void fire( R t );
/**
* Allows for handling exceptions which occur during the asynchronous operation.
*
* @author decker
* @param <R>
*/
public interface Checked<R> extends Callback<R> {
public void fireException( Throwable t );
}
public interface TwiceChecked<Q, R> extends Checked<R> {
public void initialize( Q request ) throws Exception;
}
/**
* Only invoked when the requested operation succeeds.
*
* @author decker
* @param <R>
*/
public abstract class Success<R> implements Callback<R>, Predicate<R> {
/**
* @see com.google.common.base.Predicate#apply(java.lang.Object)
* @param arg0
* @return
*/
@Override
public boolean apply( R arg0 ) {
try {
this.fire( arg0 );
return true;
} catch ( Exception ex ) {
return false;
}
}
}
/**
* Invoked only when the associated operation fails. The method {@link Callback.Checked#fireException(Throwable)} will be called with the cause of the
* failure.
*
* @author decker
*/
public abstract class Failure<R> implements Checked<R> {
/**
* @see com.eucalyptus.util.async.Callback#fire(java.lang.Object)
* @param response
*/
@Override
public final void fire( R response ) {}
/**
* @see com.eucalyptus.util.async.Callback.Checked#fireException(java.lang.Throwable)
* @param t
*/
public abstract void fireException( Throwable t );
}
public abstract class Completion<R> implements Checked<R>, Predicate<R> {
/**
* @see com.eucalyptus.util.async.Callback#fire(java.lang.Object)
* @param r
*/
@Override
public final void fire( R r ) {
this.fire( );
}
/**
* @see com.google.common.base.Predicate#apply(java.lang.Object)
* @param arg0
* @return
*/
@Override
public boolean apply( R arg0 ) {
try {
this.fire( );
return true;
} catch ( Exception ex ) {
return false;
}
}
public abstract void fire( );
public abstract void fireException( Throwable t );
}
}