com.espertech.esper.epl.join.base

Interface JoinSetComposer

All Known Implementing Classes:

JoinSetComposerAllUnidirectionalOuter, JoinSetComposerFAFImpl, JoinSetComposerHistoricalImpl, JoinSetComposerImpl, JoinSetComposerStreamToWinImpl

public interface JoinSetComposer

Interface for populating a join tuple result set from new data and old data for each stream.

Method Summary

Modifier and Type	Method and Description
boolean	allowsInit() Returns true whether initialization events per stream to populate join indexes can be processed (init method).
void	destroy() Destroy stateful index tables, if any.
void	init(EventBean[][] eventsPerStream, ExprEvaluatorContext exprEvaluatorContext) Provides initialization events per stream to composer to populate join indexes, if required
UniformPair<Set<MultiKey<EventBean>>>	join(EventBean[][] newDataPerStream, EventBean[][] oldDataPerStream, ExprEvaluatorContext exprEvaluatorContext) Return join tuple result set from new data and old data for each stream.
Set<MultiKey<EventBean>>	staticJoin() For use in iteration over join statements, this must build a join tuple result set from all events in indexes, executing query strategies for each.
void	visitIndexes(StatementAgentInstancePostLoadIndexVisitor visitor)

Method Detail

allowsInit

boolean allowsInit()

Returns true whether initialization events per stream to populate join indexes can be processed (init method).

Returns:

whether init is supported

init

void init(EventBean[][] eventsPerStream,
          ExprEvaluatorContext exprEvaluatorContext)

Provides initialization events per stream to composer to populate join indexes, if required

Parameters:

eventsPerStream - is an array of events for each stream, with null elements to indicate no events for a stream

exprEvaluatorContext - evaluator context

join

UniformPair<Set<MultiKey<EventBean>>> join(EventBean[][] newDataPerStream,
                                           EventBean[][] oldDataPerStream,
                                           ExprEvaluatorContext exprEvaluatorContext)

Return join tuple result set from new data and old data for each stream.

Parameters:

newDataPerStream - - for each stream the event array (can be null).

oldDataPerStream - - for each stream the event array (can be null).

exprEvaluatorContext - expression evaluation context

Returns:

join tuples

staticJoin

Set<MultiKey<EventBean>> staticJoin()

For use in iteration over join statements, this must build a join tuple result set from all events in indexes, executing query strategies for each.

Returns:

static join result

destroy

void destroy()

Destroy stateful index tables, if any.

visitIndexes

void visitIndexes(StatementAgentInstancePostLoadIndexVisitor visitor)