com.espertech.esper.filter

Interface FilterService

All Known Subinterfaces:

FilterServiceSPI

All Known Implementing Classes:

FilterServiceBase, FilterServiceLockCoarse, FilterServiceLockFine

public interface FilterService

Interface for filtering events by event type and event property values. Allows adding and removing filters.

Filters are defined by a FilterSpecCompiled and are associated with a FilterHandle callback. Implementations may decide if the same filter callback can be registered twice for different or some filter specifications.

The performance of an implementation of this service is crucial in achieving a high overall event throughput.

Method Summary

Modifier and Type	Method and Description
FilterServiceEntry	add(FilterValueSet filterValueSet, FilterHandle callback) Add a filter for events as defined by the filter specification, and register a callback to be invoked upon evaluation of an event that matches the filter spec.
void	destroy() Destroy the service.
long	evaluate(EventBean theEvent, Collection<FilterHandle> matches) Finds matching filters to the event passed in and collects their associated callback method.
long	evaluate(EventBean theEvent, Collection<FilterHandle> matches, int statementId) Finds matching filters to the event passed in and collects their associated callback method, for a particular statement only
long	getFiltersVersion() Returns filter version.
long	getNumEventsEvaluated() Return a count of the number of events evaluated by this service.
void	remove(FilterHandle callback, FilterServiceEntry filterServiceEntry) Remove a filter callback.
void	removeType(EventType type)
void	resetStats() Reset the number of events evaluated

Method Detail

evaluate

long evaluate(EventBean theEvent,
              Collection<FilterHandle> matches)

Finds matching filters to the event passed in and collects their associated callback method.

Parameters:

theEvent - is the event to be matched against filters

matches - is a collection that is populated via add method with any handles for matching filters

Returns:

filter current version

evaluate

long evaluate(EventBean theEvent,
              Collection<FilterHandle> matches,
              int statementId)

Finds matching filters to the event passed in and collects their associated callback method, for a particular statement only

Parameters:

theEvent - is the event to be matched against filters

matches - is a collection that is populated via add method with any handles for matching filters

statementId - statement for which to return results for

Returns:

filter current version

add

FilterServiceEntry add(FilterValueSet filterValueSet,
                       FilterHandle callback)

Add a filter for events as defined by the filter specification, and register a callback to be invoked upon evaluation of an event that matches the filter spec.

Parameters:

filterValueSet - is a specification of filter parameters, contains event type information, event property values and operators

callback - is the callback to be invoked when the filter matches an event

Returns:

entry

remove

void remove(FilterHandle callback,
            FilterServiceEntry filterServiceEntry)

Remove a filter callback.

Parameters:

callback - is the callback to be removed

filterServiceEntry - entry

getNumEventsEvaluated

long getNumEventsEvaluated()

Return a count of the number of events evaluated by this service.

Returns:

count of invocations of evaluate method

resetStats

void resetStats()

Reset the number of events evaluated

destroy

void destroy()

Destroy the service.

getFiltersVersion

long getFiltersVersion()

Returns filter version.

Returns:

filter version

removeType

void removeType(EventType type)