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.component.directvm;
018    
019    import java.util.Map;
020    import java.util.concurrent.ConcurrentHashMap;
021    import java.util.concurrent.ConcurrentMap;
022    import java.util.concurrent.atomic.AtomicInteger;
023    
024    import org.apache.camel.Endpoint;
025    import org.apache.camel.impl.DefaultComponent;
026    
027    /**
028     * Represents the component that manages {@link DirectVmEndpoint}. It holds the
029     * list of named direct-vm endpoints.
030     */
031    public class DirectVmComponent extends DefaultComponent {
032    
033        private static final AtomicInteger START_COUNTER = new AtomicInteger();
034    
035        // must keep a map of consumers on the component to ensure endpoints can lookup old consumers
036        // later in case the DirectVmEndpoint was re-created due the old was evicted from the endpoints LRUCache
037        // on DefaultCamelContext
038        private static final ConcurrentMap<String, DirectVmConsumer> CONSUMERS = new ConcurrentHashMap<String, DirectVmConsumer>();
039    
040        @Override
041        protected Endpoint createEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception {
042            DirectVmEndpoint answer = new DirectVmEndpoint(uri, this);
043            answer.configureProperties(parameters);
044            return answer;
045        }
046    
047        public DirectVmConsumer getConsumer(DirectVmEndpoint endpoint) {
048            String key = getConsumerKey(endpoint.getEndpointUri());
049            return CONSUMERS.get(key);
050        }
051    
052        public void addConsumer(DirectVmEndpoint endpoint, DirectVmConsumer consumer) {
053            String key = getConsumerKey(endpoint.getEndpointUri());
054            DirectVmConsumer existing = CONSUMERS.putIfAbsent(key, consumer);
055            if (existing != null) {
056                String contextId = existing.getEndpoint().getCamelContext().getName();
057                throw new IllegalStateException("A consumer " + existing + " already exists from CamelContext: " + contextId + ". Multiple consumers not supported");
058            }
059        }
060    
061        public void removeConsumer(DirectVmEndpoint endpoint, DirectVmConsumer consumer) {
062            String key = getConsumerKey(endpoint.getEndpointUri());
063            CONSUMERS.remove(key);
064        }
065    
066        private static String getConsumerKey(String uri) {
067            if (uri.contains("?")) {
068                // strip parameters
069                uri = uri.substring(0, uri.indexOf('?'));
070            }
071            return uri;
072        }
073    
074        @Override
075        protected void doStart() throws Exception {
076            super.doStart();
077            START_COUNTER.incrementAndGet();
078        }
079    
080        @Override
081        protected void doStop() throws Exception {
082            if (START_COUNTER.decrementAndGet() <= 0) {
083                // clear queues when no more direct-vm components in use
084                CONSUMERS.clear();
085            }
086            super.doStop();
087        }
088    
089    }