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 org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.util.DoFnInfo;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /** Contains methods for obtaining and clearing {@link DoFnInfo} instances. t */
  public interface DoFnInstanceManager {
    /**
     * Get the {@link DoFnInfo} contained by this {@link DoFnInstanceManager} without obtaining
     * ownership of that {@link DoFnInfo}. {@link DoFn} processing methods should not be called on the
     * {@link DoFn} contained within the {@link DoFnInfo} returned by this call.
     */
    DoFnInfo<?, ?> peek() throws Exception;
  
    /**
     * Get the {@link DoFnInfo} contained by this {@link DoFnInstanceManager}, and obtain ownership of
     * the returned {@link DoFnInfo}.
     */
    DoFnInfo<?, ?> get() throws Exception;
  
    /**
     * Relinquish ownership of the provided {@link DoFnInfo} after successfully completing a bundle.
     */
    void complete(DoFnInfo<?, ?> fnInfo) throws Exception;
  
    /** Relinquish ownership of the provided {@link DoFnInfo} after aborting a bundle. */
    void abort(@Nullable DoFnInfo<?, ?> fnInfo) throws Exception;
  }
  