Java tutorial
/************************************************************************* * Copyright 2009-2012 Eucalyptus Systems, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 3 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see http://www.gnu.org/licenses/. * * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need * additional information or have any questions. * * This file may incorporate work covered under the following copyright * and permission notice: * * Software License Agreement (BSD License) * * Copyright (c) 2008, Regents of the University of California * All rights reserved. * * Redistribution and use of this software in source and binary forms, * with or without modification, are permitted provided that the * following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer * in the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE * THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL, * COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE, * AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING * IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, * SANTA BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, * WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION, * REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO * IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT * NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS. ************************************************************************/ package com.eucalyptus.event; import java.util.Collection; import java.util.List; import java.util.Map; import java.util.NoSuchElementException; import java.util.Set; import java.util.concurrent.ConcurrentNavigableMap; import java.util.concurrent.ConcurrentSkipListMap; import java.util.concurrent.locks.ReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock; import com.eucalyptus.util.HasFullName; import com.eucalyptus.util.HasName; import com.google.common.base.Predicate; import com.google.common.collect.Lists; import com.google.common.collect.Maps; @SuppressWarnings("rawtypes") public abstract class AbstractNamedRegistry<TYPE extends HasFullName> { protected ReadWriteLock canHas = new ReentrantReadWriteLock(); private ConcurrentNavigableMap<String, TYPE> activeMap; private ConcurrentNavigableMap<String, TYPE> disabledMap; protected AbstractNamedRegistry() { this.activeMap = new ConcurrentSkipListMap<String, TYPE>(); this.disabledMap = new ConcurrentSkipListMap<String, TYPE>(); } public void deregister(String key) { this.canHas.writeLock().lock(); try { this.disabledMap.remove(key); this.activeMap.remove(key); } finally { this.canHas.writeLock().unlock(); } } public void register(TYPE obj) { TYPE tempObj = null; this.canHas.writeLock().lock(); try { if ((tempObj = this.disabledMap.remove(obj.getName())) == null) { tempObj = obj; } this.activeMap.putIfAbsent(tempObj.getName(), tempObj); } finally { this.canHas.writeLock().unlock(); } } public void registerDisabled(TYPE obj) { TYPE tempObj = null; this.canHas.writeLock().lock(); try { if ((tempObj = this.activeMap.remove(obj.getName())) == null) { tempObj = obj; } this.disabledMap.putIfAbsent(tempObj.getName(), tempObj); } finally { this.canHas.writeLock().unlock(); } } public List<TYPE> listDisabledValues() { this.canHas.readLock().lock(); try { return Lists.newArrayList(this.disabledMap.values()); } finally { this.canHas.readLock().unlock(); } } public List<TYPE> listValues() { this.canHas.readLock().lock(); try { return Lists.newArrayList(this.activeMap.values()); } finally { this.canHas.readLock().unlock(); } } public TYPE lookupDisabled(String name) throws NoSuchElementException { this.canHas.readLock().lock(); try { if (!this.disabledMap.containsKey(name)) { throw new NoSuchElementException( "Can't find registered object: " + name + " in " + this.getClass().getSimpleName()); } else { return this.disabledMap.get(name); } } finally { this.canHas.readLock().unlock(); } } public TYPE lookup(String name) throws NoSuchElementException { this.canHas.readLock().lock(); try { if (!this.activeMap.containsKey(name)) { throw new NoSuchElementException( "Can't find registered object: " + name + " in " + this.getClass().getSimpleName()); } else { return this.activeMap.get(name); } } finally { this.canHas.readLock().unlock(); } } public void disable(TYPE that) throws NoSuchElementException { this.disable(that.getName()); } public void disable(String name) { this.canHas.writeLock().lock(); try { TYPE obj = null; if ((obj = this.activeMap.remove(name)) == null && ((obj = this.disabledMap.remove(name)) == null)) { throw new NoSuchElementException( "Can't find registered object: " + name + " in " + this.getClass().getSimpleName()); } else { this.disabledMap.putIfAbsent(obj.getName(), obj); } } finally { this.canHas.writeLock().unlock(); } } public void enable(TYPE that) throws NoSuchElementException { this.enable(that.getName()); } public void enable(String name) throws NoSuchElementException { this.canHas.writeLock().lock(); try { TYPE obj = null; if ((obj = this.disabledMap.remove(name)) == null && ((obj = this.activeMap.remove(name)) == null)) { throw new NoSuchElementException( "Can't find registered object: " + name + " in " + this.getClass().getSimpleName()); } else { this.activeMap.putIfAbsent(obj.getName(), obj); } } finally { this.canHas.writeLock().unlock(); } } public boolean contains(TYPE obj) { return this.contains(obj.getName()); } public boolean contains(String name) { this.canHas.readLock().lock(); try { return this.activeMap.containsKey(name) || this.disabledMap.containsKey(name); } finally { this.canHas.readLock().unlock(); } } public TYPE enableFirst(Predicate<TYPE> filter) throws NoSuchElementException { this.canHas.writeLock().lock(); try { TYPE first = Maps.filterValues(this.disabledMap, filter).values().iterator().next(); if (first == null) { throw new NoSuchElementException("Disabled map is empty."); } this.activeMap.put(first.getName(), first); return first; } finally { this.canHas.writeLock().unlock(); } } @Override public String toString() { return String.format("%s [activeMap=%s, disabledMap=%s]", this.getClass().getSimpleName(), this.activeMap, this.disabledMap); } }