Package org.apache.activemq.store.kahadb.scheduler

Class JobSchedulerImpl

java.lang.Object

org.apache.activemq.util.ServiceSupport

org.apache.activemq.store.kahadb.scheduler.JobSchedulerImpl

All Implemented Interfaces:

Runnable, JobScheduler, org.apache.activemq.Service

public class JobSchedulerImpl
extends ServiceSupport
implements Runnable, JobScheduler

Method Summary

Modifier and Type	Method	Description
void	addListener(JobListener l)
protected void	doStart()
protected void	doStop(ServiceStopper stopper)
List<Job>	getAllJobs()
List<Job>	getAllJobs(long start, long finish)
protected Iterator<org.apache.activemq.store.kahadb.scheduler.JobLocation>	getAllScheduledJobs(Transaction tx)	Walks the Scheduled Job Tree and collects the add location and last update location for all scheduled jobs.
String	getName()
List<Job>	getNextScheduleJobs()
long	getNextScheduleTime()
protected void	mainLoop()
protected void	process(Transaction tx, KahaAddScheduledJobCommand command, Location location)	Adds a new Scheduled job to the index.
protected void	process(Transaction tx, KahaRemoveScheduledJobsCommand command, Location location)	Removes all scheduled jobs within a given time range.
protected void	process(Transaction tx, KahaRescheduleJobCommand command, Location location)	Reschedules a Job after it has be fired.
void	remove(long time)
void	remove(String jobId)
protected void	removeAll(Transaction tx)	Removes all jobs from the schedulers index.
void	removeAllJobs()
void	removeAllJobs(long start, long finish)
protected void	removeInRange(Transaction tx, long start, long finish, Location location)	Removes all scheduled jobs within the target range.
protected boolean	removeJobAtTime(Transaction tx, String jobId, long executionTime)	Removes a Job from the index using it's Id value and the time it is currently set to be executed.
void	removeListener(JobListener l)
void	run()
void	schedule(String jobId, ByteSequence payload, long delay)
void	schedule(String jobId, ByteSequence payload, String cronEntry)
void	schedule(String jobId, ByteSequence payload, String cronEntry, long delay, long period, int repeat)
void	setName(String name)
void	startDispatching()
void	stopDispatching()
String	toString()
void	write(DataOutput out)

Methods inherited from class org.apache.activemq.util.ServiceSupport

addServiceListener, dispose, isStarted, isStopped, isStopping, postStop, preStart, removeServiceListener, start, stop

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

setName

public void setName(String name)

getName

public String getName()

Specified by:

getName in interface JobScheduler

addListener

public void addListener(JobListener l)

Specified by:

addListener in interface JobScheduler

removeListener

public void removeListener(JobListener l)

Specified by:

removeListener in interface JobScheduler

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     long delay)
              throws IOException

Specified by:

schedule in interface JobScheduler

Throws:

IOException

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     String cronEntry)
              throws Exception

Specified by:

schedule in interface JobScheduler

Throws:

Exception

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     String cronEntry,
                     long delay,
                     long period,
                     int repeat)
              throws IOException

Specified by:

schedule in interface JobScheduler

Throws:

IOException

remove

public void remove(long time)
            throws IOException

Specified by:

remove in interface JobScheduler

Throws:

IOException

remove

public void remove(String jobId)
            throws IOException

Specified by:

remove in interface JobScheduler

Throws:

IOException

removeAllJobs

public void removeAllJobs()
                   throws IOException

Specified by:

removeAllJobs in interface JobScheduler

Throws:

IOException

removeAllJobs

public void removeAllJobs(long start,
                          long finish)
                   throws IOException

Specified by:

removeAllJobs in interface JobScheduler

Throws:

IOException

getNextScheduleTime

public long getNextScheduleTime()
                         throws IOException

Specified by:

getNextScheduleTime in interface JobScheduler

Throws:

IOException

getNextScheduleJobs

public List<Job> getNextScheduleJobs()
                              throws IOException

Specified by:

getNextScheduleJobs in interface JobScheduler

Throws:

IOException

getAllJobs

public List<Job> getAllJobs()
                     throws IOException

Specified by:

getAllJobs in interface JobScheduler

Throws:

IOException

getAllJobs

public List<Job> getAllJobs(long start,
                            long finish)
                     throws IOException

Specified by:

getAllJobs in interface JobScheduler

Throws:

IOException

process

protected void process(Transaction tx,
                       KahaAddScheduledJobCommand command,
                       Location location)
                throws IOException

Adds a new Scheduled job to the index. Must be called under index lock. This method must ensure that a duplicate add is not processed into the scheduler. On index recover some adds may be replayed and we don't allow more than one instance of a JobId to exist at any given scheduled time, so filter these out to ensure idempotence.

Parameters:

tx - Transaction in which the update is performed.

command - The new scheduled job command to process.

location - The location where the add command is stored in the journal.

Throws:

IOException - if an error occurs updating the index.

process

protected void process(Transaction tx,
                       KahaRescheduleJobCommand command,
                       Location location)
                throws IOException

Reschedules a Job after it has be fired. For jobs that are repeating this method updates the job in the index by adding it to the jobs list for the new execution time. If the job is not a cron type job then this method will reduce the repeat counter if the job has a fixed number of repeats set. The Job will be removed from the jobs list it just executed on. This method must also update the value of the last update location in the JobLocation instance so that the checkpoint worker doesn't drop the log file in which that command lives. This method must ensure that an reschedule command that references a job that doesn't exist does not cause an error since it's possible that on recover the original add might be gone and so the job should not reappear in the scheduler.

Parameters:

tx - The TX under which the index is updated.

command - The reschedule command to process.

location - The location in the index where the reschedule command was stored.

Throws:

IOException - if an error occurs during the reschedule.

process

protected void process(Transaction tx,
                       KahaRemoveScheduledJobsCommand command,
                       Location location)
                throws IOException

Removes all scheduled jobs within a given time range. The method can be used to clear the entire scheduler index by specifying a range that encompasses all time [0...Long.MAX_VALUE] or a single execution time can be removed by setting start and end time to the same value.

Parameters:

tx - The transaction under which the index is updated.

command - The remove command to process.

location - The location of the remove command in the Journal.

Throws:

IOException - if an error occurs while updating the scheduler index.

removeAll

protected void removeAll(Transaction tx)
                  throws IOException

Removes all jobs from the schedulers index. Must be called with the index locked.

Parameters:

tx - The transaction under which the index entries for this scheduler are removed.

Throws:

IOException - if an error occurs removing the jobs from the scheduler index.

removeInRange

protected void removeInRange(Transaction tx,
                             long start,
                             long finish,
                             Location location)
                      throws IOException

Removes all scheduled jobs within the target range. This method can be used to remove all the stored jobs by passing a range of [0...Long.MAX_VALUE] or it can be used to remove all jobs at a given scheduled time by passing the same time value for both start and end. If the optional location parameter is set then this method will update the store's remove location tracker with the location value and the Jobs that are being removed. This method must be called with the store index locked for writes.

Parameters:

tx - The transaction under which the index is to be updated.

start - The start time for the remove operation.

finish - The end time for the remove operation.

location - (optional) The location of the remove command that triggered this remove.

Throws:

IOException - if an error occurs during the remove operation.

removeJobAtTime

protected boolean removeJobAtTime(Transaction tx,
                                  String jobId,
                                  long executionTime)
                           throws IOException

Removes a Job from the index using it's Id value and the time it is currently set to be executed. This method will only remove the Job if it is found at the given execution time. This method must be called under index lock.

Parameters:

tx - the transaction under which this method is being executed.

jobId - the target Job Id to remove.

executionTime - the scheduled time that for the Job Id that is being removed.

Throws:

IOException - if an error occurs while removing the Job.

getAllScheduledJobs

protected Iterator<org.apache.activemq.store.kahadb.scheduler.JobLocation> getAllScheduledJobs(Transaction tx)
                                                                                        throws IOException

Walks the Scheduled Job Tree and collects the add location and last update location for all scheduled jobs. This method must be called with the index locked.

Parameters:

tx - the transaction under which this operation was invoked.

Returns:

a iterator of all referenced Location values for this JobSchedulerImpl

Throws:

IOException - if an error occurs walking the scheduler tree.

run

public void run()

Specified by:

run in interface Runnable

toString

public String toString()

Overrides:

toString in class Object

mainLoop

protected void mainLoop()

startDispatching

public void startDispatching()
                      throws Exception

Specified by:

startDispatching in interface JobScheduler

Throws:

Exception

stopDispatching

public void stopDispatching()
                     throws Exception

Specified by:

stopDispatching in interface JobScheduler

Throws:

Exception

doStart

protected void doStart()
                throws Exception

Specified by:

doStart in class ServiceSupport

Throws:

Exception

doStop

protected void doStop(ServiceStopper stopper)
               throws Exception

Specified by:

doStop in class ServiceSupport

Throws:

Exception

write

public void write(DataOutput out)
           throws IOException

Throws:

IOException