/*
* 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 and operator.
*/
public class POAnd extends BinaryComparisonOperator {
/**
*
*/
private static final long serialVersionUID = 1L;
public POAnd(OperatorKey k) {
this(k, -1);
}
public POAnd(OperatorKey k, int rp) {
super(k, rp);
resultType = DataType.BOOLEAN;
}
@Override
public void visit(PhyPlanVisitor v) throws VisitorException {
v.visitAnd(this);
}
@Override
public String name() {
return "And" + "[" + DataType.findTypeName(resultType) + "]" +" - " + mKey.toString();
}
@Override
public Result getNext(Boolean b) throws ExecException {
Result r = accumChild(null, dummyBool);
if (r != null) {
return r;
}
Result left;
left = lhs.getNext(dummyBool);
// pass on ERROR and EOP
if(left.returnStatus != POStatus.STATUS_OK && left.returnStatus != POStatus.STATUS_NULL) {
return left;
}
// truth table for AND
// t = true, n = null, f = false
// AND t n f
// 1) t t n f
// 2) n n n f
// 3) f f f f
// Short circuit - if lhs is false, return false; ROW 3 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, 1);
returnLeft = true;
}
Result right = rhs.getNext(dummyBool);
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 true - return null, in all other cases
// we can just return the rhs - ROW 1 and ROW 2 of table 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 POAnd clone() throws CloneNotSupportedException {
POAnd clone = new POAnd(new OperatorKey(mKey.scope,
NodeIdGenerator.getGenerator().getNextNodeId(mKey.scope)));
clone.cloneHelper(this);
return clone;
}
}