/*
* 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.validators;
import org.apache.pig.PigException;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.logicalLayer.LOCogroup;
import org.apache.pig.impl.logicalLayer.LOCross;
import org.apache.pig.impl.logicalLayer.LODistinct;
import org.apache.pig.impl.logicalLayer.LOFilter;
import org.apache.pig.impl.logicalLayer.LOForEach;
import org.apache.pig.impl.logicalLayer.LOJoin;
import org.apache.pig.impl.logicalLayer.LOLimit;
import org.apache.pig.impl.logicalLayer.LOLoad;
import org.apache.pig.impl.logicalLayer.LONative;
import org.apache.pig.impl.logicalLayer.LOSort;
import org.apache.pig.impl.logicalLayer.LOSplit;
import org.apache.pig.impl.logicalLayer.LOSplitOutput;
import org.apache.pig.impl.logicalLayer.LOStore;
import org.apache.pig.impl.logicalLayer.LOStream;
import org.apache.pig.impl.logicalLayer.LOUnion;
import org.apache.pig.impl.logicalLayer.LOVisitor;
import org.apache.pig.impl.logicalLayer.LogicalOperator;
import org.apache.pig.impl.logicalLayer.LogicalPlan;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.plan.DepthFirstWalker;
import org.apache.pig.impl.plan.PlanValidationException;
public class SchemaAliasVisitor extends LOVisitor {
public SchemaAliasVisitor(LogicalPlan plan) {
super(plan, new DepthFirstWalker<LogicalOperator, LogicalPlan>(plan));
}
/***
* The logic here is to check if we have duplicate alias in each schema
*/
protected void validate(LogicalOperator lo) throws PlanValidationException {
try {
Schema schema = lo.getSchema();
if (schema != null) {
for (int i = 0; i < schema.size(); i++)
for (int j = i + 1; j < schema.size(); j++) {
if (schema.getField(i) != null
&& schema.getField(j) != null
&& schema.getField(i).alias != null
&& schema.getField(j).alias != null
&& schema.getField(i).alias.equals(schema
.getField(j).alias)) {
int errCode = 1108;
String msg = "Duplicate schema alias: "
+ schema.getField(i).alias;
if (lo.getAlias()!=null)
msg = msg + " in \"" + lo.getAlias()+"\"";
throw new PlanValidationException(msg, errCode,
PigException.INPUT);
}
}
}
} catch (PlanValidationException e) {
throw e;
} catch (FrontendException e) {
int errCode = 2201;
String msg = "Could not validate schema alias";
throw new PlanValidationException(msg, errCode, PigException.INPUT);
}
}
@Override
protected void visit(LOLoad load) throws PlanValidationException {
validate(load);
}
@Override
protected void visit(LOCogroup cogroup) throws PlanValidationException {
validate(cogroup);
}
@Override
protected void visit(LOCross cross) throws PlanValidationException {
validate(cross);
}
@Override
protected void visit(LODistinct distinct) throws PlanValidationException {
validate(distinct);
}
@Override
protected void visit(LOFilter filter) throws PlanValidationException {
validate(filter);
}
@Override
protected void visit(LOForEach foreach) throws PlanValidationException {
validate(foreach);
}
@Override
protected void visit(LOJoin join) throws PlanValidationException {
validate(join);
}
@Override
protected void visit(LOLimit limit) throws PlanValidationException {
validate(limit);
}
@Override
protected void visit(LOSort sort) throws PlanValidationException {
validate(sort);
}
@Override
protected void visit(LOSplit split) throws PlanValidationException {
validate(split);
}
@Override
protected void visit(LOSplitOutput splitoutput)
throws PlanValidationException {
validate(splitoutput);
}
@Override
protected void visit(LOStore store) throws PlanValidationException {
validate(store);
return;
}
@Override
protected void visit(LOStream stream) throws PlanValidationException {
validate(stream);
return;
}
@Override
protected void visit(LOUnion union) throws PlanValidationException {
validate(union);
return;
}
@Override
protected void visit(LONative nativeMR) throws PlanValidationException {
validate(nativeMR);
return;
}
}