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.dataflow.worker;
  
  import com.google.auto.value.AutoValue;
  import org.apache.beam.runners.dataflow.worker.counters.NameContext;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ComparisonChain;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Ordering;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * Execution states are uniquely identified by the step name, the state name, and for states
   * representing IO operations, also their requesting step name, and input index.
   */
  @AutoValue
  public abstract class DataflowExecutionStateKey implements Comparable<DataflowExecutionStateKey> {
  
    /** Return the {@link NameContext} identifying the step associated with this key. */
    public abstract NameContext getStepName();
  
    /** Return the activity within the step this key represents. */
    public abstract String getStateName();
  
    /**
     * Return the step that is associated to some IO operation, such as reading of Shuffle or side
     * inputs.
     */
    public abstract @Nullable String getRequestingStepName();
  
    /**
     * Return the collection index that is associated to some operation, such as reading side inputs.
     */
    public abstract @Nullable Integer getInputIndex();
  
    /**
     * Create a new {@link DataflowExecutionStateKey} representing the given step and activity.
     *
     * @param nameContext names describing the step associated with this state key.
     * @param stateName additional string identifying the activity within that step.
     * @param requestingStepName for states representing IO activity, this is the currently-running
     *     step name.
     * @param inputIndex for states representing IO activities related to a PCollection, this is the
     *     index of the PCollection that they represent. This is mainly used to represent side inputs
     *     (e.g. index 1, 2, etc).
     */
    public static DataflowExecutionStateKey create(
        NameContext nameContext,
        String stateName,
        @Nullable String requestingStepName,
        @Nullable Integer inputIndex) {
      return new AutoValue_DataflowExecutionStateKey(
          nameContext, stateName, requestingStepName, inputIndex);
    }
  
    @Override
    public int compareTo(DataflowExecutionStateKey o) {
      return ComparisonChain.start()
          .compare(getStateName(), o.getStateName())
          .compare(
              getStepName().originalName(),
              o.getStepName().originalName(),
              Ordering.natural().nullsFirst())
          .compare(
              getStepName().stageName(), o.getStepName().stageName(), Ordering.natural().nullsFirst())
          .compare(
              getRequestingStepName(), o.getRequestingStepName(), Ordering.natural().nullsFirst())
          .compare(getInputIndex(), o.getInputIndex(), Ordering.natural().nullsFirst())
          .result();
    }
  }
  