be.e_contract.jwatchdog.datasource.rrd.RRDDatasource.java Source code

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Here is the source code for be.e_contract.jwatchdog.datasource.rrd.RRDDatasource.java

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/*
 * Java Watchdog Project.
 * Copyright (C) 2013 Frank Cornelis.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version
 * 3.0 as published by the Free Software Foundation.
 *
 * This software 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 software; if not, see 
 * http://www.gnu.org/licenses/.
 */

package be.e_contract.jwatchdog.datasource.rrd;

import java.io.File;
import java.io.IOException;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.joda.time.DateTime;
import org.rrd4j.core.jrrd.ConsolidationFunctionType;
import org.rrd4j.core.jrrd.DataChunk;
import org.rrd4j.core.jrrd.DataSource;
import org.rrd4j.core.jrrd.Header;
import org.rrd4j.core.jrrd.RRDatabase;

import be.e_contract.jwatchdog.Context;
import be.e_contract.jwatchdog.datasource.Datasource;

public class RRDDatasource implements Datasource {

    private static final Log LOG = LogFactory.getLog(RRDDatasource.class);

    private final File rrdFile;

    private final String datasourceName;

    public RRDDatasource(String rrdFilename, String datasourceName) throws Exception {
        this.rrdFile = new File(rrdFilename);
        this.datasourceName = datasourceName;
    }

    @Override
    public double[] getValues(int minutes) {
        LOG.debug("RRD file: " + this.rrdFile);
        RRDatabase rrd;
        try {
            rrd = new RRDatabase(this.rrdFile);
        } catch (IOException e) {
            throw new RuntimeException("RRD IO error: " + e.getMessage());
        }
        try {

            DateTime lastUpdate = new DateTime(rrd.getLastUpdate());
            LOG.debug("last update: " + lastUpdate);
            DateTime now = new DateTime();
            if (lastUpdate.isBefore(now.minusMinutes(minutes))) {
                LOG.warn("RRD outdated");
            }

            Header header = rrd.getHeader();
            int primaryDataPointInterval = header.getPDPStep();
            DateTime endDateTime = lastUpdate.minusSeconds(primaryDataPointInterval);
            DateTime startDateTime = endDateTime.minusMinutes(minutes);
            DataChunk dataChunk;
            try {
                dataChunk = rrd.getData(ConsolidationFunctionType.AVERAGE, startDateTime.toDate(),
                        endDateTime.toDate(), primaryDataPointInterval);
            } catch (IOException e) {
                throw new RuntimeException("RRD IO error: " + e.getMessage());
            }
            double[][] data = dataChunk.getData();
            Set<String> dataSourceNames = rrd.getDataSourcesName();
            LOG.debug("RRD datasources: " + dataSourceNames);

            int dsIdx;
            if (null != this.datasourceName) {
                if (!dataSourceNames.contains(this.datasourceName)) {
                    LOG.warn("RRD datasource name not found: " + this.datasourceName);
                    return new double[] {};
                }
                int size = dataSourceNames.size();
                for (dsIdx = 0; dsIdx < size; dsIdx++) {
                    DataSource dataSource = rrd.getDataSource(dsIdx);
                    if (dataSource.getName().equals(this.datasourceName)) {
                        break;
                    }
                }
            } else {
                dsIdx = 0;
            }

            double[] values = new double[data.length];
            for (int idx = 0; idx < data.length; idx++) {
                values[data.length - idx - 1] = data[idx][dsIdx];
            }
            return values;
        } finally {
            try {
                rrd.close();
            } catch (IOException e) {
                LOG.error("error closing RRD: " + e.getMessage());
            }
        }
    }

    @Override
    public void init(Context context) {
        // empty
    }
}