ChannelInfo.java

/*
 * ALMA - Atacama Large Millimiter Array (c) European Southern Observatory, 2004
 * Copyright by ESO (in the framework of the ALMA collaboration), All rights
 * reserved
 * 
 * This library 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 library 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 library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

package alma.acs.nc;

import java.util.HashMap;
import java.util.logging.Logger;

import com.cosylab.CDB.DAO;

import alma.acs.container.ContainerServicesBase;

/**
 * ChannelInfo is intended to provide various tidbits on information on CORBA
 * Notification Channels to the ACS NC APIs. Currently this information comes from the Configuration Database.
 * <p>
 * @TODO think about joining this class with {@link ChannelProperties}.
 * 
 * @author dfugate
 * @version $Id$
 */
public class ChannelInfo {

   /**
	 * standard logger
	 */
	private final Logger m_logger;

	/**
	 * our own private copy of the container services. used to access the ACS CDB among other things
	 */
	private final ContainerServicesBase m_services;

	/**
	 * Constructor.
	 */
	public ChannelInfo(ContainerServicesBase services) {
		m_services = services;
		// immediately grab a logger
		m_logger = m_services.getLogger();
	}

   /**
	 * The following returns a map where each key is the name of an event and the value is the maximum amount of time
	 * (in floating point seconds) an event receiver has to process the event before a warning message is logged.
	 * 
	 * @param channelName
	 *            name of the channel
	 * @return HashMap described above
	 */
   public HashMap<String, Double> getEventHandlerTimeoutMap(String channelName) {
      // initialize the return value
      HashMap<String, Double> retVal = new HashMap<String, Double>();

      // data access object to traverse the ACS CDB
      DAO dao = null;

      // keys into the DAO
      String[] keys = null;

      // get the dao for the channel...
      // ...if this fails, just return.
      try {
         dao = m_services.getCDB().get_DAO_Servant("MACI/Channels/" + channelName);
      }
      catch (Exception e) {
         m_logger.finer("No CDB entry found for '" + channelName + "' channel");
         return retVal;
      }

      // names of all the events
      try {
         keys = dao.get_string_seq("Events");
      }
      catch (Exception e) {
         m_logger.finer("CDB entry found for '" + channelName
               + "' but no Events element.");
         return retVal;
      }

      // sanity check on the number of events
      if (keys.length == 0) {
         m_logger.finer("No event definitions found for the '" + channelName
               + "' within the CDB.");
         return retVal;
      }

      // populate the hashmap
      for (int i = 0; i < keys.length; i++) {
         // determine the value location
         String timeoutLocation = "Events/" + keys[i] + "/MaxProcessTime";
         // get the value (floating point seconds)
         try {
            double value = dao.get_double(timeoutLocation);
            retVal.put(keys[i], new Double(value));
         }
         catch (Exception e) {
            e.printStackTrace();
            m_logger.severe("Could not convert 'MaxProcessTime' to floating "
                  + "point seconds for the '" + channelName + "' channel and '"
                  + keys[i] + "' event type.");
         }
      }

      return retVal;
   }
}