Source code

001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.io.network;
020
021import org.apache.reef.exception.evaluator.NetworkException;
022
023import java.util.concurrent.Callable;
024import java.util.concurrent.ExecutionException;
025
026/**
027 * Cache for network and naming services
028 */
029public interface Cache<K, V> {
030  /**
031   *  Constructs with timeout
032   *  key is evicted when it's not used for timeout milli-seconds
033   */
034
035  /**
036   * Returns a value for the key if cached; otherwise creates, caches and returns
037   * When it creates a value for a key, only one callable for the key is executed
038   *
039   * @param key      a key
040   * @param callable a value fetcher
041   * @return a value
042   * @throws NetworkException
043   */
044  public V get(K key, Callable<V> valueFetcher) throws ExecutionException;
045
046  /**
047   * Invalidates a key from the cache
048   *
049   * @param key a key
050   */
051  public void invalidate(K key);
052
053}