/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
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 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
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 * its licensees as provided above.  However, if you add GPL Version 2 code
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/*
 * $Header: /cvs/glassfish/admin/mbeans/src/java/com/sun/enterprise/admin/dottedname/DottedNameServerInfoCache.java,v 1.4 2007/05/05 05:24:07 tcfujii Exp $
 * $Revision: 1.4 $
 * $Date: 2007/05/05 05:24:07 $
 */
package com.sun.enterprise.admin.dottedname;

import java.util.HashMap;
import java.util.Set;
import java.util.Iterator;
import java.util.Collections;

import javax.management.ObjectName;

/*
	This class maintains a cache of the current server info as an optimization.
	
	The user should call refresh() prior to first use, and when wishing to get
	the current state.
	
 */
public class DottedNameServerInfoCache implements DottedNameServerInfo
{
	final DottedNameServerInfo	mSrc;
	
	Set			mConfigNames;
	Set			mServerNames;
	HashMap		mServerToConfig;
	HashMap		mConfigToServers;
	
		public
	DottedNameServerInfoCache( final DottedNameServerInfo src )
	{
		mSrc	= src;
		
		// underlying source may or may not be ready yet, so it's up
		// to the caller to call refresh() before first use.
		mConfigNames	= Collections.EMPTY_SET;
		mServerNames	= Collections.EMPTY_SET;
		mServerToConfig	= mConfigToServers	= new HashMap();
	}
	
		public synchronized Set
	getConfigNames()
		throws DottedNameServerInfo.UnavailableException
	{
		return( mConfigNames );
	}
	
		public synchronized Set
	getServerNames()
		throws DottedNameServerInfo.UnavailableException
	{
		return( mServerNames );
	}
	
		public synchronized String
	getConfigNameForServer( String serverName )
		throws DottedNameServerInfo.UnavailableException
	{
		return( (String)mServerToConfig.get( serverName ) );
	}
	
		public synchronized String []
	getServerNamesForConfig( String configName )
		throws DottedNameServerInfo.UnavailableException
	{
		return( (String [])mConfigToServers.get( configName ) );
	}
	
		void
	_refresh()
		throws DottedNameServerInfo.UnavailableException
	{
		mConfigNames	= mSrc.getConfigNames();
		mServerNames	= mSrc.getServerNames();
		
		// create mapping from server to config
		Iterator	iter	= mServerNames.iterator();
		while ( iter.hasNext() )
		{
			final String	serverName	= (String)iter.next();
			
			final String	configName	= mSrc.getConfigNameForServer( serverName );
			
			if ( configName != null )
			{
				mServerToConfig.put( serverName, configName );
			}
		}
		
		// create mapping from config to servers
		iter	= mConfigNames.iterator();
		while ( iter.hasNext() )
		{
			final String	configName	= (String)iter.next();
			
			final String [] serverNames	= mSrc.getServerNamesForConfig( configName );
			
			if ( serverNames != null )
			{
				mConfigToServers.put( configName, serverNames );
			}
		}
	}
	
		public synchronized void
	refresh()
	{
		try
		{
			_refresh();
		}
		catch( DottedNameServerInfo.UnavailableException e )
		{
			DottedNameLogger.logException( e );
		}
	}
}