| /** |
| * 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.storm.utils; |
| |
| import java.util.Map; |
| import java.util.Map.Entry; |
| |
| /** |
| * Expires keys that have not been updated in the configured number of seconds. The algorithm used will take between expirationSecs and |
| * expirationSecs * (1 + 1 / (numBuckets-1)) to actually expire the message. |
| * |
| * <p>get, put, remove, containsKey, and size take O(numBuckets) time to run. |
| * |
| * <p>The advantage of this design is that the expiration thread only locks the object for O(1) time, meaning the object |
| * is essentially always available for gets/puts. |
| */ |
| //deprecated in favor of non-threaded RotatingMap |
| @Deprecated |
| public class TimeCacheMap<K, V> { |
| //this default ensures things expire at most 50% past the expiration time |
| private static final int DEFAULT_NUM_BUCKETS = 3; |
| private final RotatingMap<K, V> rotatingMap; |
| private final Object lock = new Object(); |
| private final Thread cleaner; |
| private ExpiredCallback<K, V> callback; |
| |
| public TimeCacheMap(int expirationSecs, int numBuckets, ExpiredCallback<K, V> callback) { |
| |
| rotatingMap = new RotatingMap<>(numBuckets); |
| |
| this.callback = callback; |
| final long expirationMillis = expirationSecs * 1000L; |
| final long sleepTime = expirationMillis / (numBuckets - 1); |
| cleaner = new Thread(new Runnable() { |
| @Override |
| public void run() { |
| try { |
| while (true) { |
| Map<K, V> dead = null; |
| Time.sleep(sleepTime); |
| synchronized (lock) { |
| dead = rotatingMap.rotate(); |
| } |
| if (TimeCacheMap.this.callback != null) { |
| for (Entry<K, V> entry : dead.entrySet()) { |
| TimeCacheMap.this.callback.expire(entry.getKey(), entry.getValue()); |
| } |
| } |
| } |
| } catch (InterruptedException ex) { |
| //ignore |
| } |
| } |
| }); |
| cleaner.setDaemon(true); |
| cleaner.start(); |
| } |
| |
| public TimeCacheMap(int expirationSecs, ExpiredCallback<K, V> callback) { |
| this(expirationSecs, DEFAULT_NUM_BUCKETS, callback); |
| } |
| |
| public TimeCacheMap(int expirationSecs) { |
| this(expirationSecs, DEFAULT_NUM_BUCKETS); |
| } |
| |
| public TimeCacheMap(int expirationSecs, int numBuckets) { |
| this(expirationSecs, numBuckets, null); |
| } |
| |
| public boolean containsKey(K key) { |
| synchronized (lock) { |
| return rotatingMap.containsKey(key); |
| } |
| } |
| |
| public V get(K key) { |
| synchronized (lock) { |
| return rotatingMap.get(key); |
| } |
| } |
| |
| public void put(K key, V value) { |
| synchronized (lock) { |
| rotatingMap.put(key, value); |
| } |
| } |
| |
| public Object remove(K key) { |
| synchronized (lock) { |
| return rotatingMap.remove(key); |
| } |
| } |
| |
| public int size() { |
| synchronized (lock) { |
| return rotatingMap.size(); |
| } |
| } |
| |
| public void cleanup() { |
| cleaner.interrupt(); |
| } |
| |
| public interface ExpiredCallback<K, V> { |
| void expire(K key, V val); |
| } |
| } |