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.impl;
018
019import java.util.ArrayList;
020import java.util.Collection;
021import java.util.Map;
022import java.util.concurrent.ArrayBlockingQueue;
023import java.util.concurrent.BlockingQueue;
024
025import org.apache.camel.spi.ServicePool;
026import org.apache.camel.support.ServiceSupport;
027import org.apache.camel.util.LRUCacheFactory;
028import org.apache.camel.util.ServiceHelper;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * Default implementation to inherit for a basic service pool.
034 *
035 * @version 
036 */
037@Deprecated
038public abstract class DefaultServicePool<Key, Service> extends ServiceSupport implements ServicePool<Key, Service> {
039    protected final Logger log = LoggerFactory.getLogger(getClass());
040    protected final Map<Key, BlockingQueue<Service>> pool;
041    protected int capacity = 100;
042
043    protected DefaultServicePool() {
044        this.pool = LRUCacheFactory.newLRUCache(capacity);
045    }
046
047    public DefaultServicePool(int capacity) {
048        this.capacity = capacity;
049        this.pool = LRUCacheFactory.newLRUCache(capacity);
050    }
051
052    public int getCapacity() {
053        return capacity;
054    }
055
056    public void setCapacity(int capacity) {
057        this.capacity = capacity;
058    }
059
060    public synchronized int size() {
061        int size = 0;
062        for (BlockingQueue<Service> entry : pool.values()) {
063            size += entry.size();
064        }
065        return size;
066    }
067
068    public synchronized Service addAndAcquire(Key key, Service service) {
069        BlockingQueue<Service> entry = pool.get(key);
070        if (entry == null) {
071            entry = new ArrayBlockingQueue<>(capacity);
072            pool.put(key, entry);
073        }
074        log.trace("AddAndAcquire key: {} service: {}", key, service);
075
076        // test if queue will be full
077        if (entry.size() >= capacity) {
078            throw new IllegalStateException("Queue full");
079        }
080        return service;
081    }
082
083    public synchronized Service acquire(Key key) {
084        BlockingQueue<Service> services = pool.get(key);
085        if (services == null || services.isEmpty()) {
086            log.trace("No free services in pool to acquire for key: {}", key);
087            return null;
088        }
089
090        Service answer = services.poll();
091        log.trace("Acquire: {} service: {}", key, answer);
092        return answer;
093    }
094
095    public synchronized void release(Key key, Service service) {
096        log.trace("Release: {} service: {}", key, service);
097        BlockingQueue<Service> services = pool.get(key);
098        if (services != null) {
099            services.add(service);
100        }
101    }
102
103    public void purge() {
104        pool.clear();
105    }
106
107    protected void doStart() throws Exception {
108        log.debug("Starting service pool: {}", this);
109    }
110
111    protected void doStop() throws Exception {
112        log.debug("Stopping service pool: {}", this);
113        for (BlockingQueue<Service> entry : pool.values()) {
114            Collection<Service> values = new ArrayList<>();
115            entry.drainTo(values);
116            ServiceHelper.stopServices(values);
117            entry.clear();
118        }
119        pool.clear();
120    }
121
122}