/*
* 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.impl.logicalLayer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.pig.PigException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.plan.Operator;
import org.apache.pig.impl.plan.OperatorKey;
import org.apache.pig.impl.plan.PlanException;
import org.apache.pig.impl.plan.PlanVisitor;
import org.apache.pig.impl.plan.ProjectionMap;
import org.apache.pig.impl.plan.RequiredFields;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.impl.util.Pair;
import org.apache.pig.data.DataType;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class LOSplit extends RelationalOperator {
private static final long serialVersionUID = 2L;
private ArrayList<LogicalOperator> mOutputs;
private static Log log = LogFactory.getLog(LOSplit.class);
/**
* @param plan
* LogicalPlan this operator is a part of.
* @param key
* OperatorKey for this operator
* @param outputs
* list of aliases that are the output of the split
*/
public LOSplit(LogicalPlan plan, OperatorKey key,
ArrayList<LogicalOperator> outputs) {
super(plan, key);
mOutputs = outputs;
}
public List<LogicalOperator> getOutputs() {
return mOutputs;
}
public void setOutputs(ArrayList<LogicalOperator> outputs) {
mOutputs = outputs;
}
public void addOutput(LogicalOperator lOp) {
mOutputs.add(lOp);
}
@Override
public String name() {
return getAliasString() + "Split " + mKey.scope + "-" + mKey.id;
}
@Override
public Schema getSchema() throws FrontendException {
if (!mIsSchemaComputed) {
// get our parent's schema
Collection<LogicalOperator> s = mPlan.getPredecessors(this);
try {
LogicalOperator op = s.iterator().next();
if (null == op) {
int errCode = 1006;
String msg = "Could not find operator in plan";
throw new FrontendException(msg, errCode, PigException.INPUT, false, null);
}
LogicalOperator input = s.iterator().next();
if (input.getSchema()!=null) {
mSchema = Schema.copyAndLink(input.getSchema(), input);
}
else
mSchema = null;
mIsSchemaComputed = true;
} catch (FrontendException ioe) {
mSchema = null;
mIsSchemaComputed = false;
throw ioe;
}
}
return mSchema;
}
@Override
public boolean supportsMultipleInputs() {
return false;
}
@Override
public boolean supportsMultipleOutputs() {
return true;
}
public void visit(LOVisitor v) throws VisitorException {
v.visit(this);
}
@Override
public byte getType() {
return DataType.BAG;
}
/**
* @see org.apache.pig.impl.logicalLayer.LogicalOperator#clone()
* Do not use the clone method directly. Operators are cloned when logical plans
* are cloned using {@link LogicalPlanCloner}
*/
@Override
protected Object clone() throws CloneNotSupportedException {
LOSplit splitClone = (LOSplit)super.clone();
return splitClone;
}
@Override
public ProjectionMap getProjectionMap() {
if(mIsProjectionMapComputed) return mProjectionMap;
mIsProjectionMapComputed = true;
Schema outputSchema;
try {
outputSchema = getSchema();
} catch (FrontendException fee) {
mProjectionMap = null;
return mProjectionMap;
}
Schema inputSchema = null;
List<LogicalOperator> predecessors = (ArrayList<LogicalOperator>)mPlan.getPredecessors(this);
if(predecessors != null) {
try {
inputSchema = predecessors.get(0).getSchema();
} catch (FrontendException fee) {
mProjectionMap = null;
return mProjectionMap;
}
} else {
mProjectionMap = null;
return mProjectionMap;
}
if(Schema.equals(inputSchema, outputSchema, false, true)) {
//there is a one is to one mapping between input and output schemas
mProjectionMap = new ProjectionMap(false);
return mProjectionMap;
} else {
//problem - input and output schemas for a distinct have to match!
mProjectionMap = null;
return mProjectionMap;
}
}
@Override
public List<RequiredFields> getRequiredFields() {
List<RequiredFields> requiredFields = new ArrayList<RequiredFields>();
requiredFields.add(new RequiredFields(false, true));
return requiredFields;
}
/* (non-Javadoc)
* @see org.apache.pig.impl.plan.Operator#rewire(org.apache.pig.impl.plan.Operator, org.apache.pig.impl.plan.Operator)
*/
@Override
public void rewire(Operator<LOVisitor> oldPred, int oldPredIndex, Operator<LOVisitor> newPred, boolean useOldPred) throws PlanException {
for(LogicalOperator output: mPlan.getSuccessors(this)) {
output.rewire(oldPred, oldPredIndex, newPred, useOldPred);
}
}
@Override
public List<RequiredFields> getRelevantInputs(int output, int column) throws FrontendException {
if (!mIsSchemaComputed)
getSchema();
if (output<0)
return null;
List<LogicalOperator> successors = mPlan.getSuccessors(this);
if (output>=successors.size())
return null;
if (column<0)
return null;
// if we have schema information, check if output column is valid
if (mSchema!=null)
{
if (column >= mSchema.size())
return null;
}
ArrayList<Pair<Integer, Integer>> inputList = new ArrayList<Pair<Integer, Integer>>();
inputList.add(new Pair<Integer, Integer>(0, column));
List<RequiredFields> result = new ArrayList<RequiredFields>();
result.add(new RequiredFields(inputList));
return result;
}
}