/*
* 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.newplan.logical.optimizer;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.newplan.OperatorPlan;
import org.apache.pig.newplan.optimizer.PlanTransformListener;
/**
* A PlanTransformListener for the logical optimizer that will patch up schemas
* after a plan has been transformed.
*
*/
public class SchemaPatcher implements PlanTransformListener {
/**
* @throws FrontendException
* @link org.apache.pig.newplan.optimizer.PlanTransformListener#transformed(org.apache.pig.newplan.OperatorPlan, org.apache.pig.newplan.OperatorPlan)
*/
@Override
public void transformed(OperatorPlan fp, OperatorPlan tp) throws FrontendException {
// Walk the transformed plan and clean out the schemas and call
// getSchema again on each node. This will cause each node
// to regenerate its schema from its parent.
SchemaResetter schemaResetter = new SchemaResetter(tp);
schemaResetter.visit();
}
}