// ----------------------------------------------------------------------
   // This code is developed as part of the Java CoG Kit project
   // The terms of the license can be found at http://www.cogkit.org/license
   // This message may not be removed or altered.
   // ----------------------------------------------------------------------
   
   package fr.in2p3.jsaga.adaptor.job;
   
   import org.globus.common.CoGProperties;
  import org.globus.io.gass.server.GassServer;
  import org.ietf.jgss.GSSCredential;
  
  import java.util.*;
  
  public class GassServerFactory {
      private static Map mapping = new HashMap();
      private static Map count = new HashMap();
      private static String cogIP = CoGProperties.getDefault().getIPAddress();
  
      public synchronized static GassServer getGassServer(GSSCredential credential) throws Exception {
          if (cogIP == null) {
              if (CoGProperties.getDefault().getIPAddress() == null) {
                  throw new Exception("Could not determine this host's IP address. Please set an IP address in cog.properties");
              } else {
                  cogIP = CoGProperties.getDefault().getIPAddress();
              }
          } else if (!cogIP.equalsIgnoreCase(CoGProperties.getDefault().getIPAddress())) {
              cogIP = CoGProperties.getDefault().getIPAddress();
              shutdownGassServers();
          }
          GassServer server;
          if (mapping.containsKey(credential)) {
              server = (GassServer) mapping.get(credential);
          } else {
              try {
                  server = new GassServer(credential, 0);
              } catch (Exception e) {
                  throw new Exception("Cannot start a gass server", e);
              }
              mapping.put(credential, server);
          }
          increaseUsageCount(server);
          return server;
      }
  
      private static synchronized void increaseUsageCount(GassServer server) {
          Integer i = (Integer) count.get(server);
          if (i == null) {
              i = new Integer(1);
          } else {
              i = new Integer(i.intValue() + 1);
          }
          count.put(server, i);
      }
  
      public static synchronized void decreaseUsageCount(GassServer server) {
          Integer i = (Integer) count.get(server);
          if (i == null) {
              throw new IllegalStateException("No registered usage for server ("
                      + server + ")");
          } else if (i.intValue() == 1) {
              count.remove(server);
              mapping.remove(server.getCredentials());
              server.shutdown();
          } else {
              count.put(server, new Integer(i.intValue() - 1));
          }
      }
  
      private static synchronized void shutdownGassServers() {
          Iterator iterator = mapping.values().iterator();
          while (iterator.hasNext()) {
              GassServer gs = (GassServer) iterator.next();
              gs.shutdown();
          }
          mapping.clear();
          count.clear();
      }
  }