runners/direct-java/src/main/java/org/apache/beam/runners/direct/ExecutableGraph.java

/*
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 * distributed with this work for additional information
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 * 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,
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package org.apache.beam.runners.direct;

import java.util.Collection;
import org.apache.beam.runners.core.construction.graph.QueryablePipeline;

/**
 * The interface that enables querying of a graph of independently executable stages and the inputs
 * and outputs of those stages.
 *
 * <p>Similar to {@link QueryablePipeline}. This exists primarily for legacy reasons, as an adapter
 * interface between the 'native' and 'portable' execution models that the DirectRunner supports.
 */
public interface ExecutableGraph<ExecutableT, CollectionT> {
  Collection<ExecutableT> getRootTransforms();

  Collection<ExecutableT> getExecutables();

  ExecutableT getProducer(CollectionT collection);

  Collection<CollectionT> getProduced(ExecutableT producer);

  Collection<CollectionT> getPerElementInputs(ExecutableT transform);

  Collection<ExecutableT> getPerElementConsumers(CollectionT pCollection);
}