/*******************************************************************************
* Copyright (c) 2004, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM - Initial API and implementation
*******************************************************************************/
package org.eclipse.core.internal.utils;
import java.util.*;
import org.eclipse.core.runtime.*;
import org.eclipse.core.runtime.jobs.*;
import org.osgi.framework.Bundle;
/**
* Performs string sharing passes on all string pool participants registered with the platform.
*/
public class StringPoolJob extends Job {
private static final long INITIAL_DELAY= 10000;//ten seconds
private static final long RESCHEDULE_DELAY= 300000;//five minutes
private long lastDuration;
/**
* Stores all registered string pool participants, along with the scheduling rule required when
* running it.
*/
private Map participants= Collections.synchronizedMap(new HashMap(10));
private final Bundle systemBundle= Platform.getBundle("org.eclipse.osgi"); //$NON-NLS-1$
public StringPoolJob() {
super(Messages.utils_stringJobName);
setSystem(true);
setPriority(DECORATE);
}
/**
* Adds a string pool participant. The job periodically builds a string pool and asks all
* registered participants to share their strings in the pool. Once all participants have added
* their strings to the pool, the pool is discarded to avoid additional memory overhead.
*
* Adding a participant that is equal to a participant already registered will replace the
* scheduling rule associated with the participant, but will otherwise be ignored.
*
* @param participant The participant to add
* @param rule The scheduling rule that must be owned at the time the participant is called.
* This allows a participant to protect their data structures against access at
* unsafe times.
*
* @see #removeStringPoolParticipant(IStringPoolParticipant)
* @since 3.1
*/
public void addStringPoolParticipant(IStringPoolParticipant participant, ISchedulingRule rule) {
participants.put(participant, rule);
if (getState() == Job.SLEEPING)
wakeUp(INITIAL_DELAY);
else
schedule(INITIAL_DELAY);
}
/**
* Removes the indicated log listener from the set of registered string pool participants. If no
* such participant is registered, no action is taken.
*
* @param participant the participant to deregister
* @see #addStringPoolParticipant(IStringPoolParticipant, ISchedulingRule)
* @since 3.1
*/
public void removeStringPoolParticipant(IStringPoolParticipant participant) {
participants.remove(participant);
}
/* (non-Javadoc)
* Method declared on Job
*/
protected IStatus run(IProgressMonitor monitor) {
//if the system is shutting down, don't build
if (systemBundle.getState() == Bundle.STOPPING)
return Status.OK_STATUS;
//copy current participants to handle concurrent additions and removals to map
Map.Entry[] entries= (Map.Entry[])participants.entrySet().toArray(new Map.Entry[0]);
ISchedulingRule[] rules= new ISchedulingRule[entries.length];
IStringPoolParticipant[] toRun= new IStringPoolParticipant[entries.length];
for (int i= 0; i < toRun.length; i++) {
toRun[i]= (IStringPoolParticipant)entries[i].getKey();
rules[i]= (ISchedulingRule)entries[i].getValue();
}
final ISchedulingRule rule= MultiRule.combine(rules);
long start= -1;
int savings= 0;
final IJobManager jobManager= Job.getJobManager();
try {
jobManager.beginRule(rule, monitor);
start= System.currentTimeMillis();
savings= shareStrings(toRun, monitor);
} finally {
jobManager.endRule(rule);
}
if (start > 0) {
lastDuration= System.currentTimeMillis() - start;
if (Policy.DEBUG_STRINGS)
Policy.debug("String sharing saved " + savings + " bytes in: " + lastDuration); //$NON-NLS-1$ //$NON-NLS-2$
}
//throttle frequency if it takes too long
long scheduleDelay= Math.max(RESCHEDULE_DELAY, lastDuration * 100);
if (Policy.DEBUG_STRINGS)
Policy.debug("Rescheduling string sharing job in: " + scheduleDelay); //$NON-NLS-1$
schedule(scheduleDelay);
return Status.OK_STATUS;
}
private int shareStrings(IStringPoolParticipant[] toRun, IProgressMonitor monitor) {
final StringPool pool= new StringPool();
for (int i= 0; i < toRun.length; i++) {
if (monitor.isCanceled())
break;
final IStringPoolParticipant current= toRun[i];
SafeRunner.run(new ISafeRunnable() {
public void handleException(Throwable exception) {
//exceptions are already logged, so nothing to do
}
public void run() {
current.shareStrings(pool);
}
});
}
return pool.getSavedStringCount();
}
}