content: /*
   * 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.beam.runners.direct;
  
  import java.util.Collection;
  import org.apache.beam.sdk.util.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);
  }
  