/*
* 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;
public class Subtract extends BinaryExpressionOperator {
/**
*
*/
private static final long serialVersionUID = 1L;
public Subtract(OperatorKey k) {
super(k);
}
public Subtract(OperatorKey k, int rp) {
super(k, rp);
}
@Override
public void visit(PhyPlanVisitor v) throws VisitorException {
v.visitSubtract(this);
}
@Override
public String name() {
return "Subtract" + "[" + DataType.findTypeName(resultType) + "]" +" - " + mKey.toString();
}
/*
* This method is used to invoke the appropriate subtraction method, as Java does not provide generic
* dispatch for it.
*/
@SuppressWarnings("unchecked")
protected <T extends Number> T subtract(T a, T b, byte dataType) throws ExecException {
switch(dataType) {
case DataType.DOUBLE:
return (T) Double.valueOf((Double) a - (Double) b);
case DataType.INTEGER:
return (T) Integer.valueOf((Integer) a - (Integer) b);
case DataType.LONG:
return (T) Long.valueOf((Long) a - (Long) b);
case DataType.FLOAT:
return (T) Float.valueOf((Float) a - (Float) b);
default:
throw new ExecException("called on unsupported Number class " + DataType.findTypeName(dataType));
}
}
@SuppressWarnings("unchecked")
protected <T extends Number> Result genericGetNext(T number, byte dataType) throws ExecException {
Result r = accumChild(null, number, dataType);
if (r != null) {
return r;
}
byte status;
Result res;
T left = null, right = null;
res = lhs.getNext(left, dataType);
status = res.returnStatus;
if(status != POStatus.STATUS_OK || res.result == null) {
return res;
}
left = (T) res.result;
res = rhs.getNext(right, dataType);
status = res.returnStatus;
if(status != POStatus.STATUS_OK || res.result == null) {
return res;
}
right = (T) res.result;
res.result = subtract(left, right, dataType);
return res;
}
@Override
public Result getNext(Double d) throws ExecException {
return genericGetNext(d, DataType.DOUBLE);
}
@Override
public Result getNext(Float f) throws ExecException {
return genericGetNext(f, DataType.FLOAT);
}
@Override
public Result getNext(Integer i) throws ExecException {
return genericGetNext(i, DataType.INTEGER);
}
@Override
public Result getNext(Long l) throws ExecException {
return genericGetNext(l, DataType.LONG);
}
@Override
public Subtract clone() throws CloneNotSupportedException {
Subtract clone = new Subtract(new OperatorKey(mKey.scope,
NodeIdGenerator.getGenerator().getNextNodeId(mKey.scope)));
clone.cloneHelper(this);
return clone;
}
}