/*
* 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.stratosphere.executionengine.pactLayer.expressionOperators;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.backend.stratosphere.executionengine.pactLayer.PactOperator;
import org.apache.pig.backend.stratosphere.executionengine.pactLayer.Result;
import org.apache.pig.backend.stratosphere.executionengine.pactLayer.SOStatus;
import org.apache.pig.backend.stratosphere.executionengine.pactLayer.plans.PactPlanVisitor;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.DataByteArray;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.pen.Illustrator;
/**
* A base class for all types of expressions. All expression
* operators must extend this class.
*
*/
public abstract class ExpressionOperator extends PactOperator {
private static final Log log = LogFactory.getLog(ExpressionOperator.class);
private static final long serialVersionUID = 1L;
public ExpressionOperator(OperatorKey k) {
this(k,-1);
}
public ExpressionOperator(OperatorKey k, int rp) {
super(k, rp);
}
@Override
public void setIllustrator(Illustrator illustrator) {
this.illustrator = illustrator;
}
@Override
public boolean supportsMultipleOutputs() {
return false;
}
@Override
public Result getNext(DataBag db) throws ExecException {
return new Result();
}
@Override
public abstract void visit(PactPlanVisitor v) throws VisitorException;
/**
* Make a deep copy of this operator. This is declared here to make it
* possible to call clone on ExpressionOperators.
* @throws CloneNotSupportedException
*/
@Override
public ExpressionOperator clone() throws CloneNotSupportedException {
String s = "This expression operator does not implement clone.";
log.error(s);
throw new CloneNotSupportedException(s);
}
/**
* Get the sub-expressions of this expression.
* This is called if reducer is run as accumulative mode, all the child
* expression must be called if they have any UDF to drive the UDF.accumulate()
*/
protected abstract List<ExpressionOperator> getChildExpressions();
/** check whether this expression contains any UDF
* this is called if reducer is run as accumulative mode
* in this case, all UDFs must be called
*/
public boolean containUDF() {
if (this instanceof POUserFunc) {
return true;
}
List<ExpressionOperator> l = getChildExpressions();
if (l != null) {
for(ExpressionOperator e: l) {
if (e.containUDF()) {
return true;
}
}
}
return false;
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Object o, byte dataType) throws ExecException {
if (isAccumStarted()) {
if (child == null) {
child = getChildExpressions();
}
Result res = null;
if (child != null) {
for(ExpressionOperator e: child) {
if (e.containUDF()) {
res = e.getNext(o, dataType);
if (res.returnStatus != SOStatus.STATUS_BATCH_OK) {
return res;
}
}
}
}
res = new Result();
res.returnStatus = SOStatus.STATUS_BATCH_OK;
return res;
}
return null;
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Double d) throws ExecException {
return accumChild(child, d, DataType.DOUBLE);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Integer v) throws ExecException {
return accumChild(child, v, DataType.INTEGER);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Long l) throws ExecException {
return accumChild(child, l, DataType.LONG);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Float f) throws ExecException {
return accumChild(child, f, DataType.FLOAT);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Boolean b) throws ExecException {
return accumChild(child, b, DataType.BOOLEAN);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, String s) throws ExecException {
return accumChild(child, s, DataType.CHARARRAY);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, DataByteArray dba) throws ExecException {
return accumChild(child, dba, DataType.BYTEARRAY);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Map map) throws ExecException {
return accumChild(child, map, DataType.MAP);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, Tuple t) throws ExecException {
return accumChild(child, t, DataType.TUPLE);
}
/**
* Drive all the UDFs in accumulative mode
*/
protected Result accumChild(List<ExpressionOperator> child, DataBag db) throws ExecException {
return accumChild(child, db, DataType.BAG);
}
}