com.espertech.esper.epl.core
Class OrderByProcessorImpl

java.lang.Object
  com.espertech.esper.epl.core.OrderByProcessorImpl

All Implemented Interfaces:

OrderByProcessor

public class OrderByProcessorImpl
extends java.lang.Object
implements OrderByProcessor

An order-by processor that sorts events according to the expressions in the order_by clause.

Constructor Summary

OrderByProcessorImpl(OrderByProcessorFactoryImpl factory, AggregationService aggregationService)

Method Summary

EventBean	determineLocalMinMax(EventBean[] outgoingEvents, EventBean[][] generatingEvents, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext)
EventBean	determineLocalMinMax(EventBean[] outgoingEvents, java.lang.Object[] orderKeys)
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 isNewData, AgentInstanceContext exprEvaluatorContext, 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.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OrderByProcessorImpl

public OrderByProcessorImpl(OrderByProcessorFactoryImpl factory,
                            AggregationService aggregationService)

Method Detail

getSortKey

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

Description copied from interface: OrderByProcessor

Returns the sort key for a given row.

Specified by:

getSortKey in interface OrderByProcessor

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

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

Specified by:

getSortKey in interface OrderByProcessor

getSortKeyPerRow

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

Description copied from interface: OrderByProcessor

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

Specified by:

getSortKeyPerRow in interface OrderByProcessor

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

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

Description copied from interface: OrderByProcessor

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.

Specified by:

sort in interface OrderByProcessor

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

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

Specified by:

sort in interface OrderByProcessor

sort

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

Description copied from interface: OrderByProcessor

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

Specified by:

sort in interface OrderByProcessor

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

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

Description copied from interface: OrderByProcessor

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

Specified by:

sort in interface OrderByProcessor

Parameters:

outgoingEvents - is the events to sort

orderKeys - is the keys to sort by

exprEvaluatorContext - context for expression evalauation

Returns:

sorted events

determineLocalMinMax

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

determineLocalMinMax

public EventBean determineLocalMinMax(EventBean[] outgoingEvents,
                                      java.lang.Object[] orderKeys)