org.drools.core.rule.Behavior Maven / Gradle / Ivy
/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Licensed 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.
*/
package org.drools.core.rule;
import org.drools.core.common.EventFactHandle;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.common.InternalWorkingMemory;
import org.drools.core.spi.PropagationContext;
import org.drools.core.spi.RuleComponent;
import java.util.Collection;
/**
* An interface for all behavior implementations
*/
public interface Behavior extends RuleComponent, Cloneable {
interface Context {
Collection getFactHandles();
}
enum BehaviorType {
TIME_WINDOW( "time" ),
LENGTH_WINDOW( "length" );
private final String id;
BehaviorType( String id ) {
this.id = id;
}
public boolean matches( String id ) {
return this.id.equalsIgnoreCase( id );
}
}
/**
* Returns the type of the behavior
*/
BehaviorType getType();
/**
* Creates the context object associated with this behavior.
* The object is given as a parameter in all behavior call backs.
*/
Context createContext();
/**
* Makes the behavior aware of the new fact entering behavior's scope
*
* @param context The behavior context object
* @param fact The new fact entering behavior's scope
* @param workingMemory The working memory session reference
*
* @return true if the propagation should continue, false otherwise. I.e.,
* the behaviour has veto power over the fact propagation, and prevents
* the propagation to continue if returns false on this method.
*/
boolean assertFact(Object context,
InternalFactHandle fact,
PropagationContext pctx,
InternalWorkingMemory workingMemory);
/**
* Removes a right tuple from the behavior's scope
*
* @param context The behavior context object
* @param fact The fact leaving the behavior's scope
* @param workingMemory The working memory session reference
*/
void retractFact(Object context,
InternalFactHandle fact,
PropagationContext pctx,
InternalWorkingMemory workingMemory);
/**
* A callback method that allows behaviors to expire facts
*/
void expireFacts(Object context,
PropagationContext pctx,
InternalWorkingMemory workingMemory);
/**
* Some behaviors might change the expiration offset for the
* associated fact type. Example: time sliding windows.
*
* For these behaviors, this method must return the expiration
* offset associated to them.
*
* @return the expiration offset for this behavior or -1 if
* they don't have a time based expiration offset.
*/
long getExpirationOffset();
}