/*************************************************************************
* Copyright 2009-2012 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; version 3 of the License.
*
* 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, see http://www.gnu.org/licenses/.
*
* Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
* CA 93117, 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.
************************************************************************/
package com.eucalyptus.util;
import com.google.common.base.Predicate;
@FunctionalInterface
public interface Callback<R> {
/**
* The operation completed. Guaranteed to be called only once per corresponding dispatch.
*
* @param t
*/
public void fire( R input );
/**
* 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 input ) {
try {
this.fire( input );
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.Callback#fire(java.lang.Object)
* @param response
*/
@Override
public final void fire( R response ) {}
/**
* @see com.eucalyptus.util.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.Callback#fire(java.lang.Object)
* @param r
*/
@Override
public final void fire( R input ) {
this.fire( );
}
/**
* @see com.google.common.base.Predicate#apply(java.lang.Object)
* @param arg0
* @return
*/
@Override
public boolean apply( R input ) {
try {
this.fire( );
return true;
} catch ( Exception ex ) {
return false;
}
}
public abstract void fire( );
public abstract boolean isDone( );
}
}