/*************************************************************************
* Copyright 2009-2015 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
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* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* 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.List;
import java.util.NoSuchElementException;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import com.eucalyptus.util.HasFullName;
import com.eucalyptus.util.LockResource;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
@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 deregisterDisabled( String key ) {
try ( final LockResource lockResource = LockResource.lock( this.canHas.writeLock( ) ) ) {
this.disabledMap.remove( key );
}
}
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 final 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 {
final List<TYPE> selection = Lists.newArrayList(
Iterables.limit( Iterables.filter( this.disabledMap.values( ), filter ), 10_000 ) );
TYPE first = selection.isEmpty( ) ?
null :
selection.get( ThreadLocalRandom.current( ).nextInt( 0, selection.size( ) ) );
if ( first == null ) {
throw new NoSuchElementException( "Disabled map is empty." );
}
this.activeMap.put( first.getName( ), first );
this.disabledMap.remove( first.getName( ) );
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 );
}
}