/*************************************************************************
* Copyright 2009-2013 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.
************************************************************************/
package com.eucalyptus.autoscaling.common.internal.instances;
import javax.annotation.Nullable;
import com.google.common.base.Predicate;
/**
*
*/
public enum ConfigurationState implements Predicate<AutoScalingInstance> {
/**
* No related external configuration
*/
Nihil,
/**
* Related EC2 instance exists
*/
Instantiated,
/**
* Registered with ELB(s)
*/
Registered,
;
/**
* State matching predicate.
*
* @param instance The instance to match
* @return True if the instance is in this state
*/
@Override
public boolean apply( @Nullable final AutoScalingInstance instance ) {
return instance != null && this == instance.getConfigurationState();
}
/**
* Get a Predicate for view matching.
*/
public Predicate<AutoScalingInstanceCoreView> forView() {
return new Predicate<AutoScalingInstanceCoreView>() {
@Override
public boolean apply( @Nullable final AutoScalingInstanceCoreView instance ) {
return instance != null && ConfigurationState.this == instance.getConfigurationState();
}
};
}
/**
* A predicate to transition from one state to another.
*
* <p>The state of a given instance is transitioned if the state of the
* instance matches this configuration state. The predicate returns true if
* the state was changed.</p>
*
* @param to The state to transition to
* @return The transition function
*/
public Predicate<AutoScalingInstance> transitionTo( final ConfigurationState to ) {
return new ConfigurationStateTransition( this, to );
}
private static final class ConfigurationStateTransition implements Predicate<AutoScalingInstance> {
private final ConfigurationState from;
private final ConfigurationState to;
private ConfigurationStateTransition( final ConfigurationState from,
final ConfigurationState to ) {
this.from = from;
this.to = to;
}
@Override
public boolean apply( final AutoScalingInstance instance ) {
boolean transitioned = false;
if ( from.apply( instance ) ) {
instance.setConfigurationState( to );
instance.setRegistrationAttempts( 0 );
transitioned = true;
}
return transitioned;
}
}
}