/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.optimizer.relational;
import java.util.LinkedList;
public class RuleStack {
private RelationalPlanner planner;
private LinkedList<OptimizerRule> rules = new LinkedList<OptimizerRule>();
public void push(OptimizerRule rule) {
rules.addFirst(rule);
}
public void addLast(OptimizerRule rule) {
rules.addLast(rule);
}
public OptimizerRule pop() {
if(rules.isEmpty()) {
return null;
}
return rules.removeFirst();
}
public boolean isEmpty() {
return rules.isEmpty();
}
public int size() {
return rules.size();
}
/**
* Remove all occurrences of this rule in the stack
* @param rule The rule to remove
* @since 4.2
*/
public void remove(OptimizerRule rule) {
while(rules.remove(rule)) {}
}
public boolean contains(OptimizerRule rule) {
return rules.contains(rule);
}
public void setPlanner(RelationalPlanner planner) {
this.planner = planner;
}
public RelationalPlanner getPlanner() {
return planner;
}
public RuleStack clone() {
RuleStack clone = new RuleStack();
clone.rules.addAll(this.rules);
clone.planner = this.planner;
return clone;
}
}