com.espertech.esper.common.internal.epl.resultset.order

Interface OrderByProcessor

public interface OrderByProcessor

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

Method Summary

Modifier and Type	Method and Description
Object	getSortKey(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Returns the sort key for a given row.
Object	getSortKeyRollup(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext, AggregationGroupByRollupLevel level) Returns the sort key for a given row for rollup.
EventBean[]	sortPlain(EventBean[] outgoingEvents, EventBean[][] generatingEvents, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext, AggregationService aggregationService) Sort the output events.
EventBean[]	sortRollup(EventBean[] outgoingEvents, List<GroupByRollupKey> currentGenerators, boolean newData, AgentInstanceContext agentInstanceContext, AggregationService aggregationService) Sort the output events, using the provided group-by keys for evaluating grouped aggregation functions, and avoiding the cost of recomputing the keys.
EventBean[]	sortTwoKeys(EventBean first, Object sortKeyFirst, EventBean second, Object sortKeySecond) Sort two keys and events
EventBean[]	sortWGroupKeys(EventBean[] outgoingEvents, EventBean[][] generatingEvents, Object[] groupByKeys, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext, AggregationService aggregationService) Sort the output events, using the provided group-by keys for evaluating grouped aggregation functions, and avoiding the cost of recomputing the keys.
EventBean[]	sortWOrderKeys(EventBean[] outgoingEvents, Object[] orderKeys, ExprEvaluatorContext exprEvaluatorContext) Sort a given array of outgoing events using the sort keys returning a sorted outgoing event array.

Method Detail

sortPlain

EventBean[] sortPlain(EventBean[] outgoingEvents,
                      EventBean[][] generatingEvents,
                      boolean isNewData,
                      ExprEvaluatorContext exprEvaluatorContext,
                      AggregationService aggregationService)

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

aggregationService - aggregation svc

Returns:

an array containing the output events in sorted order

sortWGroupKeys

EventBean[] sortWGroupKeys(EventBean[] outgoingEvents,
                           EventBean[][] generatingEvents,
                           Object[] groupByKeys,
                           boolean isNewData,
                           ExprEvaluatorContext exprEvaluatorContext,
                           AggregationService aggregationService)

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 evaluation

aggregationService - aggregation svc

Returns:

an array containing the output events in sorted order

sortRollup

EventBean[] sortRollup(EventBean[] outgoingEvents,
                       List<GroupByRollupKey> currentGenerators,
                       boolean newData,
                       AgentInstanceContext agentInstanceContext,
                       AggregationService aggregationService)

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

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

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

agentInstanceContext - context for expression evaluation

aggregationService - aggregation svc

Returns:

an array containing the output events in sorted order

getSortKey

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

getSortKeyRollup

Object getSortKeyRollup(EventBean[] eventsPerStream,
                        boolean isNewData,
                        ExprEvaluatorContext exprEvaluatorContext,
                        AggregationGroupByRollupLevel level)

Returns the sort key for a given row for rollup.

Parameters:

eventsPerStream - is the row consisting of one event per stream

isNewData - is true for new data

exprEvaluatorContext - context for expression evalauation

level - rollup level

Returns:

sort key

sortWOrderKeys

EventBean[] sortWOrderKeys(EventBean[] outgoingEvents,
                           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

sortTwoKeys

EventBean[] sortTwoKeys(EventBean first,
                        Object sortKeyFirst,
                        EventBean second,
                        Object sortKeySecond)

Sort two keys and events

Parameters:

first - first

sortKeyFirst - sort key first

second - second

sortKeySecond - sort key seconds

Returns:

sorted