samza-core/src/main/java/org/apache/samza/table/batching/GetOperation.java

/*
 * 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.samza.table.batching;

import com.google.common.base.Preconditions;
import java.util.concurrent.CompletableFuture;


/**
 * Get operation.
 *
 * @param <K> The type of the key.
 */
public class GetOperation<K, V> implements Operation<K, V> {
  final K key;
  final Object[] args;
  final CompletableFuture<V> completableFuture = new CompletableFuture<>();

  public GetOperation(K key, Object ... args) {
    Preconditions.checkNotNull(key);
    Preconditions.checkNotNull(args);

    this.key = key;
    this.args = args;
  }

  /**
   * @return The key of the operation.
   */
  @Override
  public K getKey() {
    Preconditions.checkNotNull(key);

    return key;
  }

  /**
   * @return null.
   */
  @Override
  public V getValue() {
    return null;
  }

  /**
   * @return The extra arguments associated with the table.
   */
  @Override
  public Object[] getArgs() {
    return args;
  }

  CompletableFuture<V> getCompletableFuture() {
    return completableFuture;
  }

  void complete(V val) {
    completableFuture.complete(val);
  }

  void completeExceptionally(Throwable ex) {
    completableFuture.completeExceptionally(ex);
  }
}