com.linuxbox.enkive.statistics.gathering.GatheringScheduler.java Source code

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Here is the source code for com.linuxbox.enkive.statistics.gathering.GatheringScheduler.java

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/*******************************************************************************
 * Copyright 2013 The Linux Box Corporation.
 * 
 * This file is part of Enkive CE (Community Edition).
 * Enkive CE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 * 
 * Enkive CE 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public
 * License along with Enkive CE. If not, see
 * <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package com.linuxbox.enkive.statistics.gathering;

import java.text.ParseException;
import java.util.Calendar;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.CronExpression;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.springframework.scheduling.quartz.CronTriggerBean;
import org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean;

public class GatheringScheduler {
    protected List<Gatherer> gatherers = new LinkedList<Gatherer>();
    protected CronExpression schedule;
    protected int interval;
    protected Scheduler scheduler;
    protected MethodInvokingJobDetailFactoryBean jobDetail;
    protected CronTriggerBean trigger;
    protected final static Log LOGGER = LogFactory
            .getLog("com.linuxbox.enkive.statistics.gathering.GatheringScheduler");

    protected Date lastFireTime = null;

    private void setCronExpression() throws ParseException {
        if (interval < 60) {
            this.schedule = new CronExpression("0 0/" + interval + " * * * ?");
        } else if (interval == 60) {
            this.schedule = new CronExpression("0 0 * * * ?");
        } else {
            interval = 15;
            LOGGER.warn("Interval exceeds 60--reverting to 15min default interval");
            this.schedule = new CronExpression("0 0/15 * * * ?");
        }
    }

    public GatheringScheduler(String name, List<Gatherer> gatherers, Scheduler scheduler, int interval) {
        this.interval = interval;
        this.gatherers = gatherers;
        this.scheduler = scheduler;
        try {
            setCronExpression();

            // define factory
            jobDetail = new MethodInvokingJobDetailFactoryBean();
            jobDetail.setTargetObject(this);
            jobDetail.setName(name + "job");
            jobDetail.setTargetMethod("gatherAndStoreStats");
            jobDetail.setConcurrent(false);
            jobDetail.afterPropertiesSet();

            // define trigger
            this.trigger = new CronTriggerBean();
            trigger.setBeanName(name + "TrigBean");
            trigger.setJobDetail((JobDetail) jobDetail.getObject());
            trigger.setCronExpression(schedule);
            trigger.afterPropertiesSet();

            // add to schedule defined in spring xml
            scheduler.scheduleJob((JobDetail) jobDetail.getObject(), trigger);
        } catch (SchedulerException e) {
            LOGGER.error("Schedule Exception in " + name, e);
        } catch (ClassNotFoundException e) {
            LOGGER.error("ClassNotFound Exception in " + name, e);
        } catch (NoSuchMethodException e) {
            LOGGER.error("NoSuchMethod Exception in " + name, e);
        } catch (ParseException e) {
            LOGGER.error("Could not parse schedule in " + name + " (" + schedule + ")", e);
        } catch (Exception e) {
            LOGGER.error("Exception in " + name, e);
        }
    }

    private Date getEndTime() {
        Date endTime = new Date();
        long intervalMS = interval * 60 * 1000;
        if (lastFireTime != null) {
            endTime.setTime(lastFireTime.getTime() + intervalMS);
        } else {
            long r = endTime.getTime() % intervalMS;
            endTime.setTime(endTime.getTime() - r);
        }
        return endTime;
    }

    private Date getStartTime(Date endDate) {
        Calendar c = Calendar.getInstance();
        c.setTime(endDate);
        c.add(Calendar.MINUTE, -interval);
        return c.getTime();
    }

    public void gatherAndStoreStats() {
        Date endDate = getEndTime();
        Date startDate = getStartTime(endDate);
        lastFireTime = endDate;

        for (Gatherer gatherer : gatherers) {
            try {
                gatherer.storeStats(gatherer.getStatistics(startDate, endDate));
            } catch (GathererException e) {
                LOGGER.error("GathererException in GatheringScheduler for " + gatherer.getAttributes().getName(),
                        e);
            }
        }
    }
}