com.dataartisans.flink.cascading.planner.rules.BoundaryAfterMergeTransformer 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.FlowElementExpression;
import cascading.flow.planner.iso.finder.SearchOrder;
import cascading.flow.planner.iso.transformer.InsertionGraphTransformer;
import cascading.flow.planner.rule.RuleExpression;
import cascading.flow.planner.rule.transformer.RuleInsertionTransformer;
import cascading.pipe.Merge;
import static cascading.flow.planner.rule.PlanPhase.BalanceAssembly;
/**
* Injects a Boundary after a Merge in order to split of the Merge as a separate node.
*/
public class BoundaryAfterMergeTransformer extends RuleInsertionTransformer
{
public BoundaryAfterMergeTransformer() {
super(
BalanceAssembly,
new MergeMatcher(),
BoundaryElementFactory.BOUNDARY_FACTORY,
InsertionGraphTransformer.Insertion.After
);
}
public static class MergeMatcher extends RuleExpression
{
public MergeMatcher()
{
super( new MergeGraph() );
}
}
public static class MergeGraph extends ExpressionGraph {
public MergeGraph() {
super(SearchOrder.ReverseTopological, new FlowElementExpression(ElementCapture.Primary, Merge.class));
}
}
}