com.espertech.esper.epl.core
Interface OrderByProcessor

All Known Implementing Classes:

OrderByProcessorImpl, OrderByProcessorOrderedLimit, OrderByProcessorRowLimitOnly

public interface OrderByProcessor

A processor for ordering output events according to the order specified in the order-by clause.

Method Summary

java.lang.Object	getSortKey(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Returns the sort key for a given row.
java.lang.Object	getSortKey(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext, OrderByElement[] elementsForLevel)
java.lang.Object[]	getSortKeyPerRow(EventBean[] generatingEvents, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Returns the sort key for a each row where a row is a single event (no join, single stream).
EventBean[]	sort(EventBean[] outgoingEvents, EventBean[][] generatingEvents, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Sort the output events.
EventBean[]	sort(EventBean[] outgoingEvents, EventBean[][] generatingEvents, java.lang.Object[] groupByKeys, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Sort the output events, using the provided group-by keys for evaluating grouped aggregation functions, and avoiding the cost of recomputing the keys.
EventBean[]	sort(EventBean[] outgoingEvents, java.util.List<GroupByRollupKey> currentGenerators, boolean newData, AgentInstanceContext agentInstanceContext, OrderByElement[][] elementsPerLevel)
EventBean[]	sort(EventBean[] outgoingEvents, java.lang.Object[] orderKeys, ExprEvaluatorContext exprEvaluatorContext) Sort a given array of outgoing events using the sort keys returning a sorted outgoing event array.

Method Detail

sort

EventBean[] sort(EventBean[] outgoingEvents,
                 EventBean[][] generatingEvents,
                 boolean isNewData,
                 ExprEvaluatorContext exprEvaluatorContext)

Sort the output events. If the order-by processor needs group-by keys to evaluate the expressions in the order-by clause, these will be computed from the generating events.

Parameters:

outgoingEvents - - the events to be sorted

generatingEvents - - the events that generated the output events (each event has a corresponding array of generating events per different event streams)

isNewData - - indicates whether we are dealing with new data (istream) or old data (rstream)

exprEvaluatorContext - context for expression evalauation

Returns:

an array containing the output events in sorted order

sort

EventBean[] sort(EventBean[] outgoingEvents,
                 EventBean[][] generatingEvents,
                 java.lang.Object[] groupByKeys,
                 boolean isNewData,
                 ExprEvaluatorContext exprEvaluatorContext)

Sort the output events, using the provided group-by keys for evaluating grouped aggregation functions, and avoiding the cost of recomputing the keys.

Parameters:

outgoingEvents - - the events to sort

generatingEvents - - the events that generated the output events (each event has a corresponding array of generating events per different event streams)

groupByKeys - - the keys to use for determining the group-by group of output events

isNewData - - indicates whether we are dealing with new data (istream) or old data (rstream)

exprEvaluatorContext - context for expression evalauation

Returns:

an array containing the output events in sorted order

sort

EventBean[] sort(EventBean[] outgoingEvents,
                 java.util.List<GroupByRollupKey> currentGenerators,
                 boolean newData,
                 AgentInstanceContext agentInstanceContext,
                 OrderByElement[][] elementsPerLevel)

getSortKey

java.lang.Object getSortKey(EventBean[] eventsPerStream,
                            boolean isNewData,
                            ExprEvaluatorContext exprEvaluatorContext)

Returns the sort key for a given row.

Parameters:

eventsPerStream - is the row consisting of one event per stream

isNewData - is true for new data

exprEvaluatorContext - context for expression evalauation

Returns:

sort key

getSortKey

java.lang.Object getSortKey(EventBean[] eventsPerStream,
                            boolean isNewData,
                            ExprEvaluatorContext exprEvaluatorContext,
                            OrderByElement[] elementsForLevel)

getSortKeyPerRow

java.lang.Object[] getSortKeyPerRow(EventBean[] generatingEvents,
                                    boolean isNewData,
                                    ExprEvaluatorContext exprEvaluatorContext)

Returns the sort key for a each row where a row is a single event (no join, single stream).

Parameters:

generatingEvents - is the rows consisting of one event per row

isNewData - is true for new data

exprEvaluatorContext - context for expression evalauation

Returns:

sort key for each row

sort

EventBean[] sort(EventBean[] outgoingEvents,
                 java.lang.Object[] orderKeys,
                 ExprEvaluatorContext exprEvaluatorContext)

Sort a given array of outgoing events using the sort keys returning a sorted outgoing event array.

Parameters:

outgoingEvents - is the events to sort

orderKeys - is the keys to sort by

exprEvaluatorContext - context for expression evalauation

Returns:

sorted events