com.dataartisans.flink.cascading.planner.rules.BoundaryBeforeGroupByRemovalTransformer Maven / Gradle / Ivy
/*
* Copyright 2015 data Artisans GmbH
*
* Licensed 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 com.dataartisans.flink.cascading.planner.rules;
import cascading.flow.planner.iso.expression.ElementCapture;
import cascading.flow.planner.iso.expression.ExpressionGraph;
import cascading.flow.planner.iso.expression.ScopeExpression;
import cascading.flow.planner.iso.expression.TypeExpression;
import cascading.flow.planner.rule.PlanPhase;
import cascading.flow.planner.rule.RuleExpression;
import cascading.flow.planner.rule.transformer.RuleReplaceTransformer;
import cascading.pipe.Boundary;
import cascading.pipe.GroupBy;
/**
* Removes Boundaries in front of GroupBys
*/
public class BoundaryBeforeGroupByRemovalTransformer extends RuleReplaceTransformer {
public BoundaryBeforeGroupByRemovalTransformer() {
super(PlanPhase.PostResolveAssembly, new BoundaryGroupByMatcher());
}
public static class BoundaryGroupByMatcher extends RuleExpression {
public BoundaryGroupByMatcher() {
super(
(new ExpressionGraph()).
arc(
new TypeExpression(ElementCapture.Primary, Boundary.class, TypeExpression.Topo.LinearOut),
ScopeExpression.ALL,
new TypeExpression(ElementCapture.Secondary, GroupBy.class, TypeExpression.Topo.LinearIn)
)
);
}
}
}