aggregates.java

jrobin,使用纯java实现的RRD数据库,使用RRD数据库来统计数据.

/* ============================================================
 * JRobin : Pure java implementation of RRDTool's functionality
 * ============================================================
 *
 * Project Info:  http://www.jrobin.org
 * Project Lead:  Sasa Markovic ([e-mail]);
 *
 * (C) Copyright 2003-2005, by Sasa Markovic.
 *
 * Developers:    Sasa Markovic ([e-mail])
 *
 *
 * 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 org.jrobin.data;

import org.jrobin.core.ConsolFuns;
import org.jrobin.core.RrdException;
import org.jrobin.core.Util;

/**
 * Simple class which holds aggregated values (MIN, MAX, FIRST, LAST, AVERAGE and TOTAL). You
 * don't need to create objects of this class directly. Objects of this class are returned from
 * <code>getAggregates()</code> method in
 * {@link org.jrobin.core.FetchData#getAggregates(String) FetchData} and
 * {@link DataProcessor#getAggregates(String)} DataProcessor} classes.
 */
public class Aggregates implements ConsolFuns {
	double min = Double.NaN, max = Double.NaN;
	double first = Double.NaN, last = Double.NaN;
	double average = Double.NaN, total = Double.NaN;

	Aggregates() {
		// NOP;
	}

	/**
	 * Returns the minimal value
	 *
	 * @return Minimal value
	 */
	public double getMin() {
		return min;
	}

	/**
	 * Returns the maximum value
	 *
	 * @return Maximum value
	 */
	public double getMax() {
		return max;
	}

	/**
	 * Returns the first falue
	 *
	 * @return First value
	 */
	public double getFirst() {
		return first;
	}

	/**
	 * Returns the last value
	 *
	 * @return Last value
	 */
	public double getLast() {
		return last;
	}

	/**
	 * Returns average
	 *
	 * @return Average value
	 */
	public double getAverage() {
		return average;
	}

	/**
	 * Returns total value
	 *
	 * @return Total value
	 */
	public double getTotal() {
		return total;
	}

	/**
	 * Returns single aggregated value for the give consolidation function
	 *
	 * @param consolFun Consolidation function: MIN, MAX, FIRST, LAST, AVERAGE, TOTAL. These constanst
	 *                  are conveniently defined in the {@link org.jrobin.core.ConsolFuns ConsolFuns} interface.
	 * @return Aggregated value
	 * @throws RrdException Thrown if unsupported consolidation function is supplied
	 */
	public double getAggregate(String consolFun) throws RrdException {
		if (consolFun.equals(CF_AVERAGE)) {
			return average;
		}
		else if (consolFun.equals(CF_FIRST)) {
			return first;
		}
		else if (consolFun.equals(CF_LAST)) {
			return last;
		}
		else if (consolFun.equals(CF_MAX)) {
			return max;
		}
		else if (consolFun.equals(CF_MIN)) {
			return min;
		}
		else if (consolFun.equals(CF_TOTAL)) {
			return total;
		}
		else {
			throw new RrdException("Unknown consolidation function: " + consolFun);
		}
	}

	/**
	 * Returns String representing all aggregated values. Just for debugging purposes.
	 *
	 * @return String containing all aggregated values
	 */
	public String dump() {
		return "MIN=" + Util.formatDouble(min) + ", MAX=" + Util.formatDouble(max) + "\n" +
				"FIRST=" + Util.formatDouble(first) + ", LAST=" + Util.formatDouble(last) + "\n" +
				"AVERAGE=" + Util.formatDouble(average) + ", TOTAL=" + Util.formatDouble(total);
	}
}