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.Iterator;
import org.drools.util.LinkedList;
import org.drools.util.LinkedListEntry;
/**
* <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 ArrayAgendaGroup
implements
InternalAgendaGroup {
private static final long serialVersionUID = 400L;
private String name;
/** Items in the agenda. */
private LinkedList[] array;
private boolean active;
private int size;
private int index;
private int lastIndex;
public ArrayAgendaGroup() {
}
/**
* Construct an <code>AgendaGroup</code> with the given name.
*
* @param name
* The <AgendaGroup> name.
*/
public ArrayAgendaGroup(final String name,
final InternalRuleBase ruleBase) {
this.name = name;
Integer integer = (Integer) ruleBase.getAgendaGroupRuleTotals().get( name );
if ( integer == null ) {
this.array = new LinkedList[0];
} else {
this.array = new LinkedList[integer.intValue()];
}
this.index = this.array.length-1;
this.lastIndex = 0;
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
name = (String)in.readObject();
array = (LinkedList[])in.readObject();
active = in.readBoolean();
size = in.readInt();
index = in.readInt();
lastIndex = in.readInt();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject(name);
out.writeObject(array);
out.writeBoolean(active);
out.writeInt(size);
out.writeInt(index);
out.writeInt(lastIndex);
}
/* (non-Javadoc)
* @see org.drools.spi.AgendaGroup#getName()
*/
public String getName() {
return this.name;
}
public void clear() {
this.lastIndex = 0;
this.array = new LinkedList[ this.array.length ];
}
/* (non-Javadoc)
* @see org.drools.spi.AgendaGroup#size()
*/
public int size() {
return this.size;
}
public void add(final Activation activation) {
AgendaItem item = (AgendaItem) activation;
this.size++;
int seq = item.getSequenence();
if ( seq < this.index ) {
this.index = seq;
}
if ( seq > this.lastIndex ) {
this.lastIndex = seq;
}
LinkedList list = this.array[seq];
if ( list == null ) {
list = new LinkedList();
this.array[item.getSequenence()] = list;
}
list.add( new LinkedListEntry( activation ) );
}
public Activation getNext() {
Activation activation = null;
while ( this.index <= lastIndex ) {
LinkedList list = this.array[this.index];
if ( list != null ) {
activation = (Activation) ((LinkedListEntry)list.removeFirst()).getObject();
if ( list.isEmpty()) {
this.array[this.index++] = null;
}
this.size--;
break;
}
this.index++;
}
return (Activation) activation;
}
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.size == 0;
}
public Activation[] getActivations() {
Activation[] activations = new Activation[this.size];
int j = 0;
for ( int i = 0; i < this.array.length; i++ ) {;
LinkedList list = this.array[i];
if ( list != null ) {
Iterator it = list.iterator();
Activation activation = ( Activation ) ((LinkedListEntry)it.next()).getObject();
while ( activation != null) {
activations[j++] = activation;
activation = ( Activation ) it.next();
}
}
}
return activations;
}
public Activation[] getQueue() {
return getActivations();
}
public String toString() {
return "AgendaGroup '" + this.name + "'";
}
public boolean equal(final Object object) {
if ( (object == null) || !(object instanceof ArrayAgendaGroup) ) {
return false;
}
if ( ((ArrayAgendaGroup) object).name.equals( this.name ) ) {
return true;
}
return false;
}
public int hashCode() {
return this.name.hashCode();
}
public void setFocus() {
throw new UnsupportedOperationException();
}
}