package org.drools.common;
/*
* Copyright 2005 JBoss Inc
*
* 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.
*/
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.PriorityQueue;
import org.drools.spi.Activation;
import org.drools.util.BinaryHeapQueue;
import org.drools.util.Queueable;
/**
* <code>AgendaGroup</code> implementation that uses a <code>PriorityQueue</code> to prioritise the evaluation of added
* <code>ActivationQueue</code>s. The <code>AgendaGroup</code> also maintains a <code>Map</code> of <code>ActivationQueues</code>
* for requested salience values.
*
* @see PriorityQueue
* @see ActivationQueue
*
* @author <a href="mailto:mark.proctor@jboss.com">Mark Proctor</a>
* @author <a href="mailto:bob@werken.com">Bob McWhirter</a>
*
*/
public class BinaryHeapQueueAgendaGroup
implements
InternalAgendaGroup {
private static final long serialVersionUID = 400L;
private String name;
/** Items in the agenda. */
private BinaryHeapQueue queue;
private boolean active;
/**
* Construct an <code>AgendaGroup</code> with the given name.
*
* @param name
* The <AgendaGroup> name.
*/
public BinaryHeapQueueAgendaGroup() {
}
public BinaryHeapQueueAgendaGroup(final String name, final InternalRuleBase ruleBase) {
this.name = name;
this.queue = new BinaryHeapQueue( ruleBase.getConfiguration().getConflictResolver() );
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
name = (String)in.readObject();
queue = (BinaryHeapQueue)in.readObject();
active = in.readBoolean();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject(name);
out.writeObject(queue);
out.writeBoolean(active);
}
/* (non-Javadoc)
* @see org.drools.spi.AgendaGroup#getName()
*/
public String getName() {
return this.name;
}
public void clear() {
this.queue.clear();
}
/* (non-Javadoc)
* @see org.drools.spi.AgendaGroup#size()
*/
public int size() {
return this.queue.size();
}
public void add(final Activation activation) {
this.queue.enqueue( (Queueable) activation );
}
public Activation getNext() {
return (Activation) this.queue.dequeue();
}
public boolean isActive() {
return this.active;
}
public void setActive(final boolean activate) {
this.active = activate;
}
/**
* Iterates a PriorityQueue removing empty entries until it finds a populated entry and return true,
* otherwise it returns false;
*
* @param priorityQueue
* @return
*/
public boolean isEmpty() {
return this.queue.isEmpty();
}
public Activation[] getActivations() {
return (Activation[]) this.queue.toArray( new AgendaItem[this.queue.size()] );
}
public Activation[] getQueue() {
return this.queue.getQueueable();
}
public String toString() {
return "AgendaGroup '" + this.name + "'";
}
public boolean equal(final Object object) {
if ( (object == null) || !(object instanceof BinaryHeapQueueAgendaGroup) ) {
return false;
}
if ( ((BinaryHeapQueueAgendaGroup) object).name.equals( this.name ) ) {
return true;
}
return false;
}
public int hashCode() {
return this.name.hashCode();
}
public void setFocus() {
throw new UnsupportedOperationException();
}
}