org.alfresco.bm.event
Interface EventService

All Known Implementing Classes:

AbstractEventService, MongoEventService

public interface EventService

Interface for classes that handle persistence and retrieval of events.

Note that the next event is the event that should be processed next and not necessarily the event at the head of the queue.

Since:

1.0

Author:

Derek Hulley

Method Summary

long	count()
boolean	deleteEvent(Event event) Delete an event from the provider.
List<Event>	findEvents(String name, int skip, int limit) Find any event matching the given name, using the paging criteria
Event	getEvent(String id) Fetch a specific event by unique ID
Event	lockEvent(Event event, String lockOwner) Lock an event for processing by the given owner
Event	nextEvent(String dataOwner, long latestScheduledTime, long latestQueueTime) Retrieve the next event in the queue.
Event	putEvent(Event event) Adds an event to the provider.

Method Detail

count

long count()

Returns:

Returns the number of events in the queue

findEvents

List<Event> findEvents(String name,
                       int skip,
                       int limit)

Find any event matching the given name, using the paging criteria

Parameters:

name - find events with the given name

skip - the number of results to skip

limit - the maximum number of results to retrieve

Returns:

an event or null if not found

nextEvent

Event nextEvent(String dataOwner,
                long latestScheduledTime,
                long latestQueueTime)

Retrieve the next event in the queue.

This method must update the event queue time to the current time atomically.

Parameters:

dataOwner - the identifier of the client queuing events

latestQueueTime - the event scheduled time must not be greater than this

Returns:

Returns the next event in the queue or null

lockEvent

Event lockEvent(Event event,
                String lockOwner)

Lock an event for processing by the given owner

Parameters:

event - the event to lock

lockOwner - the lock owner

Returns:

Returns the locked event or null if it could not be locked.

getEvent

Event getEvent(String id)

Fetch a specific event by unique ID

Parameters:

id - the event ID

Returns:

the event or null if not found

deleteEvent

boolean deleteEvent(Event event)

Delete an event from the provider. This can be done after the event has been fully processed and there is no further requirement for it.

NOTE: The data cannot be accessed after this event.

Parameters:

event - the event to delete

Returns:

true if the event was deleted otherwise false

putEvent

Event putEvent(Event event)

Adds an event to the provider. This is done to populate the queue with a new event to be processed.

Parameters:

event - the event to add (the event ID must be null