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