/*
* 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.processor.xml;
import java.util.List;
import java.util.Map;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidProcessingException;
import org.teiid.query.QueryPlugin;
import org.teiid.query.sql.lang.Criteria;
/**
* This special condition handles recursive XML processing. If it evaluates
* to true, the Program it returns is a Program which is already on the program
* stack of the Processor Environment.
*/
public class RecurseProgramCondition extends CriteriaCondition {
private static final int NO_LIMIT = -1;
private static final boolean NO_EXCEPTION = false;
private int recursionLimit;
private boolean exceptionOnRecursionLimit;
public RecurseProgramCondition(Program subProgramToRecurse, Criteria terminationCriteria){
this(subProgramToRecurse, terminationCriteria, NO_LIMIT, NO_EXCEPTION);
}
public RecurseProgramCondition(Program subProgramToRecurse, Criteria terminationCriteria, int recursionLimit, boolean exceptionOnRecursionLimit){
super(terminationCriteria, subProgramToRecurse);
this.recursionLimit = recursionLimit;
this.exceptionOnRecursionLimit = exceptionOnRecursionLimit;
}
/**
* @see org.teiid.query.processor.xml.Condition#isProgramRecursive()
*/
public boolean isProgramRecursive() {
return true;
}
/**
* Evaluates to true, unless the termination criteria is true, or unless the recursion
* count limit has been reached
* @throws TeiidComponentException if it was indicated in the constructor that an
* exception should be thrown because the recursion count limit was reached, OR if there
* was a problem evaluating the termination condition relational criteria
* @see org.teiid.query.processor.xml.Condition#evaluate(Map, List, ProcessorEnvironment)
*/
public boolean evaluate(XMLProcessorEnvironment env, XMLContext context)
throws TeiidComponentException, TeiidProcessingException{
boolean terminate = false;
if (criteria != null) {
terminate = super.evaluate(env, context);
}
if (!terminate && this.recursionLimit != NO_LIMIT){
// Recursion limit (from model) is 1-based.
// The recursion count is also 1-based, with zero meaning the program is not
// recursive, 1 meaning the program is on it's first recursive iteration, etc.
// At this point, the condition is about to check the recursion count of the
// program on the PREVIOUS iteration. If that count is GREATER THAN or even
// EQUAL TO the recursion limit, we don't want to push the program onto the
// stack another time, so terminate.
terminate = env.getProgramRecursionCount(this.getThenProgram()) >= this.recursionLimit;
//handle the case of exception on recursion limit reached
if (terminate && this.exceptionOnRecursionLimit){
throw new TeiidComponentException("ERR.015.006.0039", QueryPlugin.Util.getString("ERR.015.006.0039")); //$NON-NLS-1$ //$NON-NLS-2$
}
}
return !terminate;
}
public String toString(){
StringBuffer s = new StringBuffer("RECURSE "); //$NON-NLS-1$
s.append("termination Criteria "); //$NON-NLS-1$
s.append(criteria);
s.append(", recursion limit "); //$NON-NLS-1$
if (this.recursionLimit == NO_LIMIT){
s.append("none"); //$NON-NLS-1$
} else {
s.append(this.recursionLimit);
}
s.append(", exception on limit "); //$NON-NLS-1$
s.append(this.exceptionOnRecursionLimit);
return s.toString();
}
}