/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.POStatus;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.Result;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor;
import org.apache.pig.data.DataType;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.NodeIdGenerator;
import org.apache.pig.impl.plan.VisitorException;
/**
* Boolean or operator.
*/
public class POOr extends BinaryComparisonOperator {
/**
*
*/
private static final long serialVersionUID = 1L;
public POOr(OperatorKey k) {
this(k, -1);
}
public POOr(OperatorKey k, int rp) {
super(k, rp);
resultType = DataType.BOOLEAN;
}
@Override
public void visit(PhyPlanVisitor v) throws VisitorException {
v.visitOr(this);
}
@Override
public String name() {
return "Or" + "[" + DataType.findTypeName(resultType) + "]" +" - " + mKey.toString();
}
@Override
public Result getNextBoolean() throws ExecException {
Result r = accumChild(null, DataType.BOOLEAN);
if (r != null) {
return r;
}
Result left;
left = lhs.getNextBoolean();
// pass on ERROR and EOP
if(left.returnStatus != POStatus.STATUS_OK && left.returnStatus != POStatus.STATUS_NULL) {
return left;
}
// truth table for OR
// t = true, n = null, f = false
// OR t n f
// 1) t t t t
// 2) n t n n
// 3) f t n f
// Short circuit. if lhs is true, return true - ROW 1 above is handled with this
boolean returnLeft = false;
if (left.result != null && ((Boolean)left.result).booleanValue()) {
if (illustrator == null)
return left;
illustratorMarkup(null, left.result, 0);
returnLeft = true;;
}
Result right = rhs.getNextBoolean();
if (returnLeft)
return left;
// pass on ERROR and EOP
if(right.returnStatus != POStatus.STATUS_OK && right.returnStatus != POStatus.STATUS_NULL) {
return right;
}
// if the lhs is null and rhs is false - return null , in all other cases, we can
// just return rhs - ROW 2 and ROW 3 above
if(left.result == null && right.result != null && !((Boolean)right.result).booleanValue()) {
return left;
}
// No matter what, what we get from the right side is what we'll
// return, null, true, or false.
if (right.result != null)
illustratorMarkup(null, right.result, (Boolean) right.result ? 0 : 1);
return right;
}
@Override
public POOr clone() throws CloneNotSupportedException {
POOr clone = new POOr(new OperatorKey(mKey.scope,
NodeIdGenerator.getGenerator().getNextNodeId(mKey.scope)));
clone.cloneHelper(this);
return clone;
}
}