com.espertech.esper.common.internal.epl.historical.common

Class HistoricalEventViewableBase

java.lang.Object

com.espertech.esper.common.internal.epl.historical.common.HistoricalEventViewableBase

All Implemented Interfaces:

AgentInstanceMgmtCallback, HistoricalEventViewable, Viewable, Iterable<EventBean>

Direct Known Subclasses:

HistoricalEventViewableDatabase, HistoricalEventViewableMethod

public abstract class HistoricalEventViewableBase
extends Object
implements Viewable, HistoricalEventViewable

Implements a poller viewable that uses a polling strategy, a cache and some input parameters extracted from event streams to perform the polling.

Field Summary

Fields

Modifier and Type	Field and Description
protected View	child
protected HistoricalDataCache	dataCache
protected ExprEvaluatorContext	exprEvaluatorContext
protected HistoricalEventViewableFactoryBase	factory
protected static EventBean[][]	NULL_ROWS
protected PollExecStrategy	pollExecStrategy

Fields inherited from interface com.espertech.esper.common.internal.view.core.Viewable

EPTYPE

Fields inherited from interface com.espertech.esper.common.internal.context.util.AgentInstanceMgmtCallback

INSTANCE_NO_ACTION

Constructor Summary

Constructors

Constructor and Description
HistoricalEventViewableBase(HistoricalEventViewableFactoryBase factory, PollExecStrategy pollExecStrategy, ExprEvaluatorContext exprEvaluatorContext)

Method Summary

Modifier and Type	Method and Description
View	getChild()
ThreadLocal<HistoricalDataCache>	getDataCacheThreadLocal()
EventType	getEventType() Provides metadata information about the type of object the event collection contains.
HistoricalDataCache	getOptionalDataCache()
boolean	hasRequiredStreams() Returns true if the parameters expressions to the historical require other stream's data, or false if there are no parameters or all parameter expressions are only contants and variables without properties of other stream events.
Iterator<EventBean>	iterator() Allows iteration through all elements in this viewable.
EventTable[][]	poll(EventBean[][] lookupEventsPerStream, PollResultIndexingStrategy indexingStrategy, ExprEvaluatorContext exprEvaluatorContext) Poll for stored historical or reference data using events per stream and returing for each event-per-stream row a separate list with events representing the poll result.
void	setChild(View view)
void	stop(AgentInstanceStopServices services)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface com.espertech.esper.common.internal.context.util.AgentInstanceMgmtCallback

transfer

Field Detail

factory

protected final HistoricalEventViewableFactoryBase factory

pollExecStrategy

protected final PollExecStrategy pollExecStrategy

exprEvaluatorContext

protected final ExprEvaluatorContext exprEvaluatorContext

dataCache

protected HistoricalDataCache dataCache

child

protected View child

NULL_ROWS

protected static final EventBean[][] NULL_ROWS

Constructor Detail

HistoricalEventViewableBase

public HistoricalEventViewableBase(HistoricalEventViewableFactoryBase factory,
                                   PollExecStrategy pollExecStrategy,
                                   ExprEvaluatorContext exprEvaluatorContext)

Method Detail

stop

public void stop(AgentInstanceStopServices services)

Specified by:

stop in interface AgentInstanceMgmtCallback

setChild

public void setChild(View view)

Specified by:

setChild in interface Viewable

getChild

public View getChild()

Specified by:

getChild in interface Viewable

poll

public EventTable[][] poll(EventBean[][] lookupEventsPerStream,
                           PollResultIndexingStrategy indexingStrategy,
                           ExprEvaluatorContext exprEvaluatorContext)

Description copied from interface: HistoricalEventViewable

Poll for stored historical or reference data using events per stream and returing for each event-per-stream row a separate list with events representing the poll result.

Specified by:

poll in interface HistoricalEventViewable

Parameters:

lookupEventsPerStream - is the events per stream where the first dimension is a number of rows (often 1 depending on windows used) and the second dimension is the number of streams participating in a join.

indexingStrategy - the strategy to use for converting poll results into a indexed table for fast lookup

exprEvaluatorContext - context for expression evalauation

Returns:

array of lists with one list for each event-per-stream row

getEventType

public EventType getEventType()

Description copied from interface: Viewable

Provides metadata information about the type of object the event collection contains.

Specified by:

getEventType in interface HistoricalEventViewable

Specified by:

getEventType in interface Viewable

Returns:

metadata for the objects in the collection

iterator

public Iterator<EventBean> iterator()

Description copied from interface: Viewable

Allows iteration through all elements in this viewable. The iterator will return the elements in the collection in their natural order, or, if there is no natural ordering, in some unpredictable order.

Specified by:

iterator in interface Viewable

Specified by:

iterator in interface Iterable<EventBean>

Returns:

an iterator which will go through all current elements in the collection.

getDataCacheThreadLocal

public ThreadLocal<HistoricalDataCache> getDataCacheThreadLocal()

Specified by:

getDataCacheThreadLocal in interface HistoricalEventViewable

hasRequiredStreams

public boolean hasRequiredStreams()

Description copied from interface: HistoricalEventViewable

Returns true if the parameters expressions to the historical require other stream's data, or false if there are no parameters or all parameter expressions are only contants and variables without properties of other stream events.

Specified by:

hasRequiredStreams in interface HistoricalEventViewable

Returns:

indicator whether properties are required for parameter evaluation

getOptionalDataCache

public HistoricalDataCache getOptionalDataCache()

Specified by:

getOptionalDataCache in interface HistoricalEventViewable