/*
* The MIT License
*
* Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.model;
import hudson.triggers.SafeTimerTask;
import hudson.triggers.Trigger;
import hudson.ExtensionPoint;
import hudson.Extension;
import hudson.ExtensionList;
import java.util.logging.Logger;
import java.util.Random;
import java.util.Timer;
/**
* Extension point to perform a periodic task in Hudson (through {@link Timer}.)
*
* <p>
* This extension point is useful if your plugin needs to perform some work in the background periodically
* (for example, monitoring, batch processing, garbage collection, etc.)
*
* <p>
* Put {@link Extension} on your class to have it picked up and registered automatically, or
* manually insert this to {@link Trigger#timer}.
*
* <p>
* This class is designed to run a short task. Implementations whose periodic work takes a long time
* to run should extend from {@link AsyncPeriodicWork} instead.
*
* @author Kohsuke Kawaguchi
* @see AsyncPeriodicWork
*/
public abstract class PeriodicWork extends SafeTimerTask implements ExtensionPoint {
protected final Logger logger = Logger.getLogger(getClass().getName());
/**
* Gets the number of milliseconds between successive executions.
*
* <p>
* Hudson calls this method once to set up a recurring timer, instead of
* calling this each time after the previous execution completed. So this class cannot be
* used to implement a non-regular recurring timer.
*
* <p>
* IOW, the method should always return the same value.
*/
public abstract long getRecurrencePeriod();
/**
* Gets the number of milliseconds til the first execution.
*
* <p>
* By default it chooses the value randomly between 0 and {@link #getRecurrencePeriod()}
*/
public long getInitialDelay() {
return Math.abs(new Random().nextLong())%getRecurrencePeriod();
}
/**
* Returns all the registered {@link PeriodicWork}s.
*/
public static ExtensionList<PeriodicWork> all() {
return Hudson.getInstance().getExtensionList(PeriodicWork.class);
}
// time constants
protected static final long MIN = 1000*60;
protected static final long HOUR =60*MIN;
protected static final long DAY = 24*HOUR;
}