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.distributedlog.io;
  
  import java.util.concurrent.CompletableFuture;
  import java.util.function.Function;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  
  /**
   * A {@code AsyncCloseable} is a source or destination of data that can be closed asynchronously.
   * The close method is invoked to release resources that the object is
   * holding (such as open files).
   */
  public interface AsyncCloseable {
  
      Function<AsyncCloseable, CompletableFuture<Void>> CLOSE_FUNC = closeable -> closeable.asyncClose();
  
      Function<AsyncCloseable, CompletableFuture<Void>> CLOSE_FUNC_IGNORE_ERRORS =
          closeable -> FutureUtils.ignore(closeable.asyncClose());
  
      AsyncCloseable NULL = () -> FutureUtils.Void();
  
      /**
       * Closes this source and releases any system resources associated
       * with it. If the source is already closed then invoking this
       * method has no effect.
       *
       * @return future representing the close result.
       */
      CompletableFuture<Void> asyncClose();
  }
  