MCStatistics.java

/*******************************************************************************
 * ALMA - Atacama Large Millimeter Array
 * Copyright (c) ESO - European Southern Observatory, 2011
 * (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.nsstatistics;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang.StringUtils;

import Monitor.UData;

import gov.sandia.CosNotification.NotificationServiceMonitorControlPackage.InvalidName;

public abstract class MCStatistics {
	
	private final ChannelData parent;
	protected final String mcStatName;
	protected final List<ChannelParticipantName> children = new ArrayList<ChannelParticipantName>();

	private String mcStatFullName;
	
	public MCStatistics(ChannelData parent, String mcStatName) {
		this.parent = parent;
		this.mcStatName = mcStatName;
	}
	
	/**
	 * Subclass implementations retrieve notify service statistics from {@link #mc}. 
	 */
	public abstract String getStatistics();
	
	/**
	 * This should be used by implementations of {@link #getStatistics()}.
	 */
	protected UData getMcData() {
		if (mcStatFullName == null) {
			mcStatFullName = getChannelPrefix(true) + mcStatName;
		}
		try {
			NotifyServiceData notifyServiceData = parent.getParent();
			if (notifyServiceData.isReachable()) {
				return notifyServiceData.getMc().get_statistic(mcStatFullName).data_union;
			}
			else {
				// This is a shortcut to not wait for a TRANSIENT or TIMEOUT in case of an unreachable notify service.
				// It produces an ugly log, and should never happen if we have enough "if (notifyService.isReachable())" checks higher up in the call stack.
				throw new RuntimeException("Failed to get statistics from unreachable notify service " + notifyServiceData.getName());
			}
		} catch (InvalidName ex) {
			// Try again with channel Id instead of channel name (no TAO extensions used when creating this NC)
			String mcStatFullNameTmp = getChannelPrefix(false) + mcStatName;
			try {
				 UData ret = parent.getParent().getMc().get_statistic(mcStatFullNameTmp).data_union;
				 // next time use this ID-based stat name right away 
				 mcStatFullName = mcStatFullNameTmp;
				 return ret;
			} catch (InvalidName ex2) {
				// nothing else. It is enough to report on the first ex
			}
			// Todo: deal better with this error. Could be wrong channel name (including NC missing after notify service restart)
			// or an unsupported (misspelled etc) statistics name.
			System.out.println("Invalid name: '" + mcStatFullName + 
					"'; valid names are " + StringUtils.join(parent.getParent().getMc().get_statistic_names(), ' '));
			mcStatFullName = null; // not sure if trying again next time will help, but let's try
			throw new RuntimeException(ex);
		}
	}
	
	public ChannelData getParent() {
		return parent;
	}

	/**
	 * The NC prefix must be computed "on the fly", because at least in case of the NC ID 
	 * not all data is available when this MCStatistics is created.
	 * @param useNcName <code>true</code> means to use the NC name if available, <code>false</code> means to use the NC ID.
	 */
	private String getChannelPrefix(boolean useNcName) {
		String channelPrefix = null;
		String factoryName = getParent().getParent().getFactoryName();
		if (useNcName) {
			String channelName = getParent().getName();
			channelPrefix = factoryName + "/" + channelName + "/";
		}
		else {
			int channelId = getParent().getNcId();
			channelPrefix = factoryName + "/" + channelId + "/";
		}
		return channelPrefix;
	}
	
	/**
	 * Gets the (possibly empty) {@link #children} list an Object[], which becomes tree node children.
	 */
	public Object[] getChildren() {
		return children.toArray();
	}

	/**
	 * TODO: unify MC path handling with class MCProxy
	 * @param sc
	 * @param i
	 * @return
	 */
	protected String toSimpleName(String fullMcName, int i) {
		String[] nameParts = fullMcName.split("/");
		String nameSimple = nameParts[nameParts.length-1];
		return nameSimple;
	}

}