001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.util;
018
019import java.util.concurrent.atomic.AtomicBoolean;
020
021import org.apache.camel.util.concurrent.ThreadHelper;
022import org.slf4j.Logger;
023import org.slf4j.LoggerFactory;
024
025/**
026 * Factory to create {@link LRUCache} instances.
027 */
028public final class LRUCacheFactory {
029
030    private static final Logger LOG = LoggerFactory.getLogger(LRUCacheFactory.class);
031
032    private static final AtomicBoolean INIT = new AtomicBoolean();
033
034    private LRUCacheFactory() {
035    }
036
037    /**
038     * Warm-up the LRUCache to startup Apache Camel faster.
039     */
040    public static void warmUp() {
041        // create a dummy map in a separate thread to warm-up the Caffeine cache concurrently
042        // while Camel is starting up. This allows us to overall startup Camel a bit faster
043        // as Caffeine takes 150+ millis to initialize.
044        if (INIT.compareAndSet(false, true)) {
045            // only need to init Caffeine once in the JVM/classloader
046            Runnable task = () -> {
047                StopWatch watch = new StopWatch();
048                LOG.debug("Warming up LRUCache ...");
049                newLRUCache(16);
050                LOG.debug("Warming up LRUCache complete in {} millis", watch.taken());
051            };
052
053            String threadName = ThreadHelper.resolveThreadName(null, "LRUCacheFactory");
054
055            Thread thread = new Thread(task, threadName);
056            thread.start();
057        }
058    }
059
060    /**
061     * Constructs an empty <tt>LRUCache</tt> instance with the
062     * specified maximumCacheSize, and will stop on eviction.
063     *
064     * @param maximumCacheSize the max capacity.
065     * @throws IllegalArgumentException if the initial capacity is negative
066     */
067    public static LRUCache newLRUCache(int maximumCacheSize) {
068        LOG.trace("Creating LRUCache with maximumCacheSize: {}", maximumCacheSize);
069        return new LRUCache(maximumCacheSize);
070    }
071
072    /**
073     * Constructs an empty <tt>LRUCache</tt> instance with the
074     * specified initial capacity, maximumCacheSize, and will stop on eviction.
075     *
076     * @param initialCapacity  the initial capacity.
077     * @param maximumCacheSize the max capacity.
078     * @throws IllegalArgumentException if the initial capacity is negative
079     */
080    public static LRUCache newLRUCache(int initialCapacity, int maximumCacheSize) {
081        LOG.trace("Creating LRUCache with initialCapacity: {}, maximumCacheSize: {}", initialCapacity, maximumCacheSize);
082        return new LRUCache(initialCapacity, maximumCacheSize);
083    }
084
085    /**
086     * Constructs an empty <tt>LRUCache</tt> instance with the
087     * specified initial capacity, maximumCacheSize,load factor and ordering mode.
088     *
089     * @param initialCapacity  the initial capacity.
090     * @param maximumCacheSize the max capacity.
091     * @param stopOnEviction   whether to stop service on eviction.
092     * @throws IllegalArgumentException if the initial capacity is negative
093     */
094    public static LRUCache newLRUCache(int initialCapacity, int maximumCacheSize, boolean stopOnEviction) {
095        LOG.trace("Creating LRUCache with initialCapacity: {}, maximumCacheSize: {}, stopOnEviction: {}", initialCapacity, maximumCacheSize, stopOnEviction);
096        return new LRUCache(initialCapacity, maximumCacheSize, stopOnEviction);
097    }
098
099    /**
100     * Constructs an empty <tt>LRUSoftCache</tt> instance with the
101     * specified maximumCacheSize, and will stop on eviction.
102     *
103     * @param maximumCacheSize the max capacity.
104     * @throws IllegalArgumentException if the initial capacity is negative
105     */
106    public static LRUSoftCache newLRUSoftCache(int maximumCacheSize) {
107        LOG.trace("Creating LRUSoftCache with maximumCacheSize: {}", maximumCacheSize);
108        return new LRUSoftCache(maximumCacheSize);
109    }
110
111    /**
112     * Constructs an empty <tt>LRUWeakCache</tt> instance with the
113     * specified maximumCacheSize, and will stop on eviction.
114     *
115     * @param maximumCacheSize the max capacity.
116     * @throws IllegalArgumentException if the initial capacity is negative
117     */
118    public static LRUWeakCache newLRUWeakCache(int maximumCacheSize) {
119        LOG.trace("Creating LRUWeakCache with maximumCacheSize: {}", maximumCacheSize);
120        return new LRUWeakCache(maximumCacheSize);
121    }
122}