com.espertech.esper.schedule

Interface SchedulingService

All Superinterfaces:

TimeProvider

All Known Subinterfaces:

SchedulingServiceSPI

All Known Implementing Classes:

SchedulingServiceAudit, SchedulingServiceImpl, SupportSchedulingServiceImpl

public interface SchedulingService
extends TimeProvider

Interface for a service that allows to add and remove handles (typically storing callbacks) for a certain time which are returned when the evaluate method is invoked and the current time is on or after the handle's registered time. It is the expectation that the setTime method is called with same or ascending values for each subsequent call. Handles with are triggered are automatically removed by implementations.

Method Summary

Modifier and Type	Method and Description
void	add(long afterMSec, ScheduleHandle handle, long scheduleSlot) Add a callback for after the given milliseconds from the current time.
void	destroy() Destroy the service.
void	evaluate(Collection<ScheduleHandle> handles) Evaluate the current time and add to the collection any handles scheduled for execution.
Long	getFurthestTimeHandle() Returns furthest in the future handle.
int	getScheduleHandleCount() Returns count of handles.
int	getTimeHandleCount() Returns time handle count.
boolean	isScheduled(ScheduleHandle handle) Returns true if the handle has been scheduled already.
void	remove(ScheduleHandle handle, long scheduleSlot) Remove a handle.
void	setTime(long timestamp) Set the time based upon which the evaluation of events invokes callbacks.

Methods inherited from interface com.espertech.esper.schedule.TimeProvider

getTime

Method Detail

add

void add(long afterMSec,
         ScheduleHandle handle,
         long scheduleSlot)
  throws ScheduleServiceException

Add a callback for after the given milliseconds from the current time. If the same callback (equals) was already added before, the method will not add a new callback or change the existing callback to a new time, but throw an exception.

Parameters:

afterMSec - number of millisec to get a callback

handle - to add

scheduleSlot - allows ordering of concurrent callbacks

Throws:

ScheduleServiceException - thrown if the add operation did not complete

remove

void remove(ScheduleHandle handle,
            long scheduleSlot)
     throws ScheduleServiceException

Remove a handle. If the handle to be removed was not found an exception is thrown.

Parameters:

handle - to remove

scheduleSlot - for which the callback was added

Throws:

ScheduleServiceException - thrown if the callback was not located

setTime

void setTime(long timestamp)

Set the time based upon which the evaluation of events invokes callbacks.

Parameters:

timestamp - to set

evaluate

void evaluate(Collection<ScheduleHandle> handles)

Evaluate the current time and add to the collection any handles scheduled for execution.

Parameters:

handles - is a collection of handles populated by the service with any callbacks due for the current time

destroy

void destroy()

Destroy the service.

getTimeHandleCount

int getTimeHandleCount()

Returns time handle count.

Returns:

count

getFurthestTimeHandle

Long getFurthestTimeHandle()

Returns furthest in the future handle.

Returns:

future handle

getScheduleHandleCount

int getScheduleHandleCount()

Returns count of handles.

Returns:

count

isScheduled

boolean isScheduled(ScheduleHandle handle)

Returns true if the handle has been scheduled already.

Parameters:

handle - to check

Returns:

indicator whether the handle is in use