rrdtoolkit.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.core;

import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.LinkedList;
import java.util.Arrays;

/**
 * <p>Class used to perform various complex operations on RRD files. Use an instance of the
 * RrdToolkit class to:</p>
 * <ul>
 * <li>add datasource to a RRD file.
 * <li>add archive to a RRD file.
 * <li>remove datasource from a RRD file.
 * <li>remove archive from a RRD file.
 * </ul>
 * <p>All these operations can be performed on the copy of the original RRD file, or on the
 * original file itself (with possible backup file creation)</p>
 * <p/>
 * <p><b><u>IMPORTANT</u></b>: NEVER use methods found in this class on 'live' RRD files
 * (files which are currently in use).</p>
 */
public class RrdToolkit {
	/**
	 * Creates a new RRD file with one more datasource in it. RRD file is created based on the
	 * existing one (the original RRD file is not modified at all). All data from
	 * the original RRD file is copied to the new one.
	 *
	 * @param sourcePath	path to a RRD file to import data from (will not be modified)
	 * @param destPath	  path to a new RRD file (will be created)
	 * @param newDatasource Datasource definition to be added to the new RRD file
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void addDatasource(String sourcePath, String destPath, DsDef newDatasource)
			throws IOException, RrdException {
		if (Util.sameFilePath(sourcePath, destPath)) {
			throw new RrdException("Source and destination paths are the same");
		}
		RrdDb rrdSource = new RrdDb(sourcePath);
		try {
			RrdDef rrdDef = rrdSource.getRrdDef();
			rrdDef.setPath(destPath);
			rrdDef.addDatasource(newDatasource);
			RrdDb rrdDest = new RrdDb(rrdDef);
			try {
				rrdSource.copyStateTo(rrdDest);
			}
			finally {
				rrdDest.close();
			}
		}
		finally {
			rrdSource.close();
		}
	}

	/**
	 * <p>Adds one more datasource to a RRD file.</p>
	 * <p>WARNING: This method is potentialy dangerous! It will modify your RRD file.
	 * It is highly recommended to preserve the original RRD file (<i>saveBackup</i>
	 * should be set to <code>true</code>). The backup file will be created in the same
	 * directory as the original one with <code>.bak</code> extension added to the
	 * original name.</p>
	 * <p>Before applying this method, be sure that the specified RRD file is not in use
	 * (not open)</p>
	 *
	 * @param sourcePath	path to a RRD file to add datasource to.
	 * @param newDatasource Datasource definition to be added to the RRD file
	 * @param saveBackup	true, if backup of the original file should be created;
	 *                      false, otherwise
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void addDatasource(String sourcePath, DsDef newDatasource, boolean saveBackup)
			throws IOException, RrdException {
		String destPath = Util.getTmpFilename();
		addDatasource(sourcePath, destPath, newDatasource);
		copyFile(destPath, sourcePath, saveBackup);
	}

	/**
	 * Creates a new RRD file with one datasource removed. RRD file is created based on the
	 * existing one (the original RRD file is not modified at all). All remaining data from
	 * the original RRD file is copied to the new one.
	 *
	 * @param sourcePath path to a RRD file to import data from (will not be modified)
	 * @param destPath   path to a new RRD file (will be created)
	 * @param dsName	 Name of the Datasource to be removed from the new RRD file
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void removeDatasource(String sourcePath, String destPath, String dsName)
			throws IOException, RrdException {
		if (Util.sameFilePath(sourcePath, destPath)) {
			throw new RrdException("Source and destination paths are the same");
		}
		RrdDb rrdSource = new RrdDb(sourcePath);
		try {
			RrdDef rrdDef = rrdSource.getRrdDef();
			rrdDef.setPath(destPath);
			rrdDef.removeDatasource(dsName);
			RrdDb rrdDest = new RrdDb(rrdDef);
			try {
				rrdSource.copyStateTo(rrdDest);
			}
			finally {
				rrdDest.close();
			}
		}
		finally {
			rrdSource.close();
		}
	}

	/**
	 * <p>Removes single datasource from a RRD file.</p>
	 * <p>WARNING: This method is potentialy dangerous! It will modify your RRD file.
	 * It is highly recommended to preserve the original RRD file (<i>saveBackup</i>
	 * should be set to <code>true</code>). The backup file will be created in the same
	 * directory as the original one with <code>.bak</code> extension added to the
	 * original name.</p>
	 * <p>Before applying this method, be sure that the specified RRD file is not in use
	 * (not open)</p>
	 *
	 * @param sourcePath path to a RRD file to remove datasource from.
	 * @param dsName	 Name of the Datasource to be removed from the RRD file
	 * @param saveBackup true, if backup of the original file should be created;
	 *                   false, otherwise
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void removeDatasource(String sourcePath, String dsName, boolean saveBackup)
			throws IOException, RrdException {
		String destPath = Util.getTmpFilename();
		removeDatasource(sourcePath, destPath, dsName);
		copyFile(destPath, sourcePath, saveBackup);
	}

	/**
	 * Renames single datasource in the given RRD file.
	 *
	 * @param sourcePath Path to a RRD file
	 * @param oldDsName  Old datasource name
	 * @param newDsName  New datasource name
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error (invalid path or datasource names,
	 *                      for example)
	 */
	public static void renameDatasource(String sourcePath, String oldDsName, String newDsName)
			throws IOException, RrdException {
		RrdDb rrd = new RrdDb(sourcePath);
		try {
			if (rrd.containsDs(oldDsName)) {
				Datasource datasource = rrd.getDatasource(oldDsName);
				datasource.setDsName(newDsName);
			}
			else {
				throw new RrdException("Could not find datasource [" + oldDsName + "] in file " + sourcePath);
			}
		}
		finally {
			rrd.close();
		}
	}

	/**
	 * Updates single or all datasource names in the specified RRD file
	 * by appending '!' (if not already present). Datasources with names ending with '!'
	 * will never store NaNs in RRA archives (zero value will be used instead). Might be useful
	 * from time to time
	 *
	 * @param sourcePath Path to a RRD file
	 * @param dsName	 Datasource name or null if you want to rename all datasources
	 * @return Number of datasources successfully renamed
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error (invalid path or datasource name,
	 *                      for example)
	 */
	public static int forceZerosForNans(String sourcePath, String dsName) throws IOException, RrdException {
		RrdDb rrd = new RrdDb(sourcePath);
		try {
			Datasource[] datasources;
			if (dsName == null) {
				datasources = rrd.getDatasources();
			}
			else {
				if (rrd.containsDs(dsName)) {
					datasources = new Datasource[] {rrd.getDatasource(dsName)};
				}
				else {
					throw new RrdException("Could not find datasource [" + dsName + "] in file " + sourcePath);
				}
			}
			int count = 0;
			for (Datasource datasource : datasources) {
				String currentDsName = datasource.getDsName();
				if (!currentDsName.endsWith(DsDef.FORCE_ZEROS_FOR_NANS_SUFFIX)) {
					datasource.setDsName(currentDsName + DsDef.FORCE_ZEROS_FOR_NANS_SUFFIX);
					count++;
				}
			}
			return count;
		}
		finally {
			rrd.close();
		}
	}

	/**
	 * Creates a new RRD file with one more archive in it. RRD file is created based on the
	 * existing one (the original RRD file is not modified at all). All data from
	 * the original RRD file is copied to the new one.
	 *
	 * @param sourcePath path to a RRD file to import data from (will not be modified)
	 * @param destPath   path to a new RRD file (will be created)
	 * @param newArchive Archive definition to be added to the new RRD file
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void addArchive(String sourcePath, String destPath, ArcDef newArchive)
			throws IOException, RrdException {
		if (Util.sameFilePath(sourcePath, destPath)) {
			throw new RrdException("Source and destination paths are the same");
		}
		RrdDb rrdSource = new RrdDb(sourcePath);
		try {
			RrdDef rrdDef = rrdSource.getRrdDef();
			rrdDef.setPath(destPath);
			rrdDef.addArchive(newArchive);
			RrdDb rrdDest = new RrdDb(rrdDef);
			try {
				rrdSource.copyStateTo(rrdDest);
			}
			finally {
				rrdDest.close();
			}
		}
		finally {
			rrdSource.close();
		}
	}

	/**
	 * <p>Adds one more archive to a RRD file.</p>
	 * <p>WARNING: This method is potentialy dangerous! It will modify your RRD file.
	 * It is highly recommended to preserve the original RRD file (<i>saveBackup</i>
	 * should be set to <code>true</code>). The backup file will be created in the same
	 * directory as the original one with <code>.bak</code> extension added to the
	 * original name.</p>
	 * <p>Before applying this method, be sure that the specified RRD file is not in use
	 * (not open)</p>
	 *
	 * @param sourcePath path to a RRD file to add datasource to.
	 * @param newArchive Archive definition to be added to the RRD file
	 * @param saveBackup true, if backup of the original file should be created;
	 *                   false, otherwise
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void addArchive(String sourcePath, ArcDef newArchive, boolean saveBackup)
			throws IOException, RrdException {
		String destPath = Util.getTmpFilename();
		addArchive(sourcePath, destPath, newArchive);
		copyFile(destPath, sourcePath, saveBackup);
	}

	/**
	 * Creates a new RRD file with one archive removed. RRD file is created based on the
	 * existing one (the original RRD file is not modified at all). All relevant data from
	 * the original RRD file is copied to the new one.
	 *
	 * @param sourcePath path to a RRD file to import data from (will not be modified)
	 * @param destPath   path to a new RRD file (will be created)
	 * @param consolFun  Consolidation function of Archive which should be removed
	 * @param steps	  Number of steps for Archive which should be removed
	 * @throws IOException  Thrown in case of I/O error
	 * @throws RrdException Thrown in case of JRobin specific error
	 */
	public static void removeArchive(String sourcePath, String destPath, String consolFun, int steps)
			throws IOException, RrdException {
		if (Util.sameFilePath(sourcePath, destPath)) {
			throw new RrdException("Source and destination paths are the same");
		}
		RrdDb rrdSource = new RrdDb(sourcePath);
		try {
			RrdDef rrdDef = rrdSource.getRrdDef();
			rrdDef.setPath(destPath);
			rrdDef.removeArchive(consolFun, steps);
			RrdDb rrdDest = new RrdDb(rrdDef);
			try {
				rrdSource.copyStateTo(rrdDest);
			}
			finally {
				rrdDest.close();
			}
		}
		finally {
			rrdSource.close();
		}
	}

	/**
	 * <p>Removes one archive from a RRD file.</p>
	 * <p>WARNING: This method is potentialy dangerous! It will modify your RRD file.
	 * It is highly recommended to preserve the original RRD file (<i>saveBackup</i>
	 * should be set to <code>true</code>). The backup file will be created in the same