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.cluster; 018 019import java.util.ArrayList; 020import java.util.List; 021import java.util.Optional; 022import java.util.concurrent.locks.StampedLock; 023import java.util.function.Consumer; 024 025import org.apache.camel.CamelContext; 026import org.apache.camel.cluster.CamelClusterEventListener; 027import org.apache.camel.cluster.CamelClusterMember; 028import org.apache.camel.cluster.CamelClusterService; 029import org.apache.camel.cluster.CamelClusterView; 030import org.apache.camel.support.ServiceSupport; 031import org.apache.camel.util.concurrent.LockHelper; 032 033public abstract class AbstractCamelClusterView extends ServiceSupport implements CamelClusterView { 034 private final CamelClusterService clusterService; 035 private final String namespace; 036 private final List<CamelClusterEventListener> listeners; 037 private final StampedLock lock; 038 private CamelContext camelContext; 039 040 protected AbstractCamelClusterView(CamelClusterService cluster, String namespace) { 041 this.clusterService = cluster; 042 this.namespace = namespace; 043 this.listeners = new ArrayList<>(); 044 this.lock = new StampedLock(); 045 } 046 047 @Override 048 public void setCamelContext(CamelContext camelContext) { 049 this.camelContext = camelContext; 050 } 051 052 @Override 053 public CamelContext getCamelContext() { 054 return camelContext; 055 } 056 057 @Override 058 public CamelClusterService getClusterService() { 059 return this.clusterService; 060 } 061 062 @Override 063 public String getNamespace() { 064 return this.namespace; 065 } 066 067 @Override 068 public void addEventListener(CamelClusterEventListener listener) { 069 if (listener == null) { 070 return; 071 } 072 073 LockHelper.doWithWriteLock( 074 lock, 075 () -> { 076 listeners.add(listener); 077 078 if (isRunAllowed()) { 079 // if the view has already been started, fire known events so 080 // the consumer can catch up. 081 082 if (CamelClusterEventListener.Leadership.class.isInstance(listener)) { 083 CamelClusterEventListener.Leadership.class.cast(listener).leadershipChanged(this, getLeader()); 084 } 085 086 if (CamelClusterEventListener.Membership.class.isInstance(listener)) { 087 CamelClusterEventListener.Membership ml = CamelClusterEventListener.Membership.class.cast(listener); 088 089 for (CamelClusterMember member: getMembers()) { 090 ml.memberAdded(this, member); 091 } 092 } 093 } 094 } 095 ); 096 } 097 098 @Override 099 public void removeEventListener(CamelClusterEventListener listener) { 100 if (listener == null) { 101 return; 102 } 103 104 LockHelper.doWithWriteLock(lock, () -> listeners.removeIf(l -> l == listener)); 105 } 106 107 // ************************************** 108 // Events 109 // ************************************** 110 111 private <T extends CamelClusterEventListener> void doWithListener(Class<T> type, Consumer<T> consumer) { 112 LockHelper.doWithReadLock( 113 lock, 114 () -> { 115 for (int i = 0; i < listeners.size(); i++) { 116 CamelClusterEventListener listener = listeners.get(i); 117 118 if (type.isInstance(listener)) { 119 consumer.accept(type.cast(listener)); 120 } 121 } 122 } 123 ); 124 } 125 126 protected void fireLeadershipChangedEvent(Optional<CamelClusterMember> leader) { 127 doWithListener( 128 CamelClusterEventListener.Leadership.class, 129 listener -> listener.leadershipChanged(this, leader) 130 ); 131 } 132 133 protected void fireMemberAddedEvent(CamelClusterMember member) { 134 doWithListener( 135 CamelClusterEventListener.Membership.class, 136 listener -> listener.memberAdded(this, member) 137 ); 138 } 139 140 protected void fireMemberRemovedEvent(CamelClusterMember member) { 141 doWithListener( 142 CamelClusterEventListener.Membership.class, 143 listener -> listener.memberRemoved(this, member) 144 ); 145 } 146}