EndpointQueue.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011, Red Hat, Inc. and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.restcomm.media.control.mgcp.controller.naming;

import java.util.ArrayList;

import org.apache.log4j.Logger;
import org.restcomm.media.concurrent.ConcurrentCyclicFIFO;
import org.restcomm.media.control.mgcp.controller.MgcpEndpoint;
import org.restcomm.media.control.mgcp.controller.MgcpEndpointStateListener;
import org.restcomm.media.spi.EndpointInstaller;
import org.restcomm.media.spi.utils.Text;


/**
 * Storage for endpoints of same type with search and reordering functions.
 * 
 * @author yulian oifa
 */
public class EndpointQueue implements MgcpEndpointStateListener {
    //reserved space for endpoint queue
    private final static int SIZE = 100;
    
    //wildcards
    private final static Text ANY = new Text("$");
    private final static Text ALL = new Text("*");
    
    //queue of endpoints
    private ArrayList<Holder> completeList=new ArrayList<Holder>(SIZE);
    private ConcurrentCyclicFIFO<MgcpEndpoint> queue = new ConcurrentCyclicFIFO<MgcpEndpoint>();
    
    //reference for just found endpoind
    //private Holder holder;
    
    //index
    private int k;
    
    private EndpointInstaller installer;
    
    public  Logger logger = Logger.getLogger(EndpointQueue.class);
    
    public void setInstaller(EndpointInstaller installer)
    {
    	this.installer=installer;
    }
    
    /**
     * Adds new endpoint to the queue.
     * 
     * @param endpoint the endpoint to be added
     */
    public void add(MgcpEndpoint endpoint) {
    	Holder holder=new Holder(endpoint);
    	endpoint.setMgcpEndpointStateListener(this);
    	completeList.add(holder);
        queue.offer(endpoint);
    }
    
    /**
     * Removes endpoint from the queue.
     * 
     * @param endpoint the endpoint to be removed.
     */
    /*public void remove(MgcpEndpoint endpoint) {
    	for(int i=0;i<completeList.size();i++)
    		if(completeList.get(i).endpoint==endpoint)
    		{
    			completeList.remove(i);
    			break;
    		}    	    	
    }*/
     
    /**
     * Finds endpoints matching to name pattern.
     * 
     * If "any" endpoint was requested, then first matching endpoint will be locked
     * and not available for search in future until this endpoint will be explicitly unlocked.
     * 
     * @param name the name pattern for search
     * @param endpoints collection which will be filled by found endpoints
     * @return the number of found endpoints.
     */
    public int find(Text name, MgcpEndpoint[] endpoints) {
    	//return all endpoint if all requested
        if (name.equals(ALL)) {
            k = 0;
            for(int i=0;i<completeList.size();i++) {
                endpoints[k++] = completeList.get(i).endpoint;
            }
            
            return completeList.size();
        }
        
        //return first free if ANY endpoint requested
        if (name.equals(ANY)) {        	        	
        	MgcpEndpoint endp=queue.poll();
        	while(endp==null && installer!=null && installer.canExpand())
        	{
        		if(logger.isDebugEnabled())    	
            		logger.debug("No free endpoints,expanding");            		
            	
        		synchronized(installer)
        		{
        			installer.newEndpoint();
        		}
        		
        		endp=queue.poll();
        	}
        		
        	if(endp!=null) {
        		endp.lock();
        		endpoints[0] = endp;
        		if(logger.isDebugEnabled())    	
            	{
            		logger.debug("Endpoint " + endp.getName() + " taken (free="+queue.size()+")");
            	}
        		return 1;        		            
        	}
        	        	
            return 0;
        }
               
        int value=name.toInteger();
        if(value>0 && value<=completeList.size())
        {
        	endpoints[0] = completeList.get(value-1).endpoint;
        	return 1;
        }
        
        return 0;
    }
    
    @Override
    public void onFreed(MgcpEndpoint endpoint)
    {
    	queue.offer(endpoint);    
    	if(logger.isDebugEnabled())    	
    	{
    	    logger.debug("Endpoint " + endpoint.getName() + " released (free="+queue.size()+")");
    	}
    }
    
    private class Holder {
        protected MgcpEndpoint endpoint;
        protected Text name;
        
        protected Holder(MgcpEndpoint endpoint) {
            this.endpoint = endpoint;
            String[] tokens = endpoint.getName().split("/");
            this.name = new Text(tokens[tokens.length - 1]);            
        }
    }
}