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.sdk;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkNotNull;
  
  import org.apache.beam.sdk.io.FileSystems;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.options.PipelineOptionsValidator;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.util.InstanceBuilder;
  import org.apache.beam.sdk.values.PBegin;
  
  /**
   * A {@link PipelineRunner} runs a {@link Pipeline}.
   *
   * @param <ResultT> the type of the result of {@link #run}, often a handle to a running job.
   */
  public abstract class PipelineRunner<ResultT extends PipelineResult> {
  
    /**
     * Constructs a runner from the provided {@link PipelineOptions}.
     *
     * @return The newly created runner.
     */
    public static PipelineRunner<? extends PipelineResult> fromOptions(PipelineOptions options) {
      checkNotNull(options);
      PipelineOptionsValidator.validate(PipelineOptions.class, options);
  
      // (Re-)register standard FileSystems. Clobbers any prior credentials.
      FileSystems.setDefaultPipelineOptions(options);
  
      @SuppressWarnings("unchecked")
      PipelineRunner<? extends PipelineResult> result =
          InstanceBuilder.ofType(PipelineRunner.class)
              .fromClass(options.getRunner())
              .fromFactoryMethod("fromOptions")
              .withArg(PipelineOptions.class, options)
              .build();
      return result;
    }
  
    /**
     * Creates a runner from the default app {@link PipelineOptions}.
     *
     * @return The newly created runner.
     */
    public static PipelineRunner<? extends PipelineResult> create() {
      return fromOptions(PipelineOptionsFactory.create());
    }
  
    /**
     * Processes the given {@link Pipeline}, potentially asynchronously, returning a runner-specific
     * type of result.
     */
    public abstract ResultT run(Pipeline pipeline);
  
    /** Creates a {@link Pipeline} out of a single {@link PTransform} step, and executes it. */
    public ResultT run(PTransform<PBegin, ?> pTransform, PipelineOptions options) {
      Pipeline p = Pipeline.create(options);
      p.apply(pTransform);
      return run(p);
    }
  
    /**
     * Overloaded {@link PTransform} runner that runs with the default app {@link PipelineOptions}.
     */
    public ResultT run(PTransform<PBegin, ?> pTransform) {
      return run(pTransform, PipelineOptionsFactory.create());
    }
  }
  