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