com.espertech.esper.view.ext

Class TimeOrderView

java.lang.Object

com.espertech.esper.view.ViewSupport

com.espertech.esper.view.ext.TimeOrderView

All Implemented Interfaces:

StopCallback, CloneableView, DataWindowView, EventCollection, GroupableView, StoppableView, View, Viewable, ViewDataVisitable, Iterable<EventBean>

public class TimeOrderView
extends ViewSupport
implements DataWindowView, CloneableView, StoppableView, StopCallback

Window retaining timestamped events up to a given number of seconds such that older events that arrive later are sorted into the window and released in timestamp order.

The insert stream consists of all arriving events. The remove stream consists of events in order of timestamp value as supplied by each event.

Timestamp values on events should match engine time. The window compares engine time to timestamp value and releases events when the event's timestamp is less then engine time minus interval size (the event is older then the window tail).

The view accepts 2 parameters. The first parameter is the field name to get the event timestamp value from, the second parameter defines the interval size.

Field Summary

Fields

Modifier and Type	Field and Description
protected AgentInstanceViewFactoryChainContext	agentInstanceContext
protected int	eventCount
protected EPStatementHandleCallback	handle
protected boolean	isCallbackScheduled
protected IStreamSortRankRandomAccess	optionalSortedRandomAccess
protected long	scheduleSlot
protected TreeMap<Object,Object>	sortedEvents
protected ExprTimePeriodEvalDeltaConst	timeDeltaComputation

Fields inherited from class com.espertech.esper.view.ViewSupport

EMPTY_VIEW_ARRAY, parent

Constructor Summary

Constructors

Constructor and Description
TimeOrderView(AgentInstanceViewFactoryChainContext agentInstanceContext, ViewFactory viewFactory, ExprNode timestampExpr, ExprEvaluator timestampEvaluator, ExprTimePeriodEvalDeltaConst timeDeltaComputation, IStreamSortRankRandomAccess optionalSortedRandomAccess)

Method Summary

Modifier and Type	Method and Description
View	cloneView() Duplicates the view.
protected void	expire() This method removes (expires) objects from the window and schedules a new callback for the time when the next oldest message would expire from the window.
EventType	getEventType() Provides metadata information about the type of object the event collection contains.
ExprTimePeriodEvalDeltaConst	getTimeDeltaComputation()
protected Long	getTimestamp(EventBean newEvent)
ExprNode	getTimestampExpression() Returns the timestamp property name.
ViewFactory	getViewFactory()
void	internalHandleAdd(Object sortValues, EventBean newDataItem)
void	internalHandleExpired(Object sortValues, EventBean oldDataItem)
void	internalHandleExpired(Object sortValues, List<EventBean> oldDataItems)
void	internalHandleRemoved(Object sortValues, EventBean oldDataItem)
boolean	isEmpty() True to indicate the sort window is empty, or false if not empty.
Iterator<EventBean>	iterator() Allows iteration through all elements in this event collection.
void	stop() Stops the underlying resources.
void	stopSchedule()
void	stopView()
String	toString()
void	update(EventBean[] newData, EventBean[] oldData) Notify that data has been added or removed from the Viewable parent.
void	visitView(ViewDataVisitor viewDataVisitor)

Methods inherited from class com.espertech.esper.view.ViewSupport

addView, addView, dumpChildViews, dumpUpdateParams, dumpUpdateParams, findDescendent, findViewIndex, getParent, getViews, hasViews, removeAllViews, removeView, removeView, setParent, updateChildren, updateChildren

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.espertech.esper.view.View

getParent, setParent

Methods inherited from interface com.espertech.esper.view.Viewable

addView, getViews, hasViews, removeAllViews, removeView

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

agentInstanceContext

protected final AgentInstanceViewFactoryChainContext agentInstanceContext

timeDeltaComputation

protected final ExprTimePeriodEvalDeltaConst timeDeltaComputation

optionalSortedRandomAccess

protected final IStreamSortRankRandomAccess optionalSortedRandomAccess

scheduleSlot

protected final long scheduleSlot

handle

protected final EPStatementHandleCallback handle

sortedEvents

protected TreeMap<Object,Object> sortedEvents

isCallbackScheduled

protected boolean isCallbackScheduled

eventCount

protected int eventCount

Constructor Detail

TimeOrderView

public TimeOrderView(AgentInstanceViewFactoryChainContext agentInstanceContext,
                     ViewFactory viewFactory,
                     ExprNode timestampExpr,
                     ExprEvaluator timestampEvaluator,
                     ExprTimePeriodEvalDeltaConst timeDeltaComputation,
                     IStreamSortRankRandomAccess optionalSortedRandomAccess)

Method Detail

getTimestampExpression

public ExprNode getTimestampExpression()

Returns the timestamp property name.

Returns:

property name supplying timestamp values

getTimeDeltaComputation

public ExprTimePeriodEvalDeltaConst getTimeDeltaComputation()

cloneView

public View cloneView()

Description copied from interface: CloneableView

Duplicates the view.

Expected to return a same view in initialized state for grouping.

Specified by:

cloneView in interface CloneableView

Returns:

cloned view

getEventType

public final EventType getEventType()

Description copied from interface: EventCollection

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

Specified by:

getEventType in interface EventCollection

Returns:

metadata for the objects in the collection

update

public final void update(EventBean[] newData,
                         EventBean[] oldData)

Description copied from interface: View

Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view.

If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification.

When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

Specified by:

update in interface View

Parameters:

newData - is the new data that has been added to the parent view

oldData - is the old data that has been removed from the parent view

internalHandleAdd

public void internalHandleAdd(Object sortValues,
                              EventBean newDataItem)

internalHandleRemoved

public void internalHandleRemoved(Object sortValues,
                                  EventBean oldDataItem)

internalHandleExpired

public void internalHandleExpired(Object sortValues,
                                  EventBean oldDataItem)

internalHandleExpired

public void internalHandleExpired(Object sortValues,
                                  List<EventBean> oldDataItems)

getTimestamp

protected Long getTimestamp(EventBean newEvent)

isEmpty

public boolean isEmpty()

True to indicate the sort window is empty, or false if not empty.

Returns:

true if empty sort window

iterator

public final Iterator<EventBean> iterator()

Description copied from interface: EventCollection

Allows iteration through all elements in this event collection. 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 EventCollection

Specified by:

iterator in interface Iterable<EventBean>

Returns:

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

toString

public final String toString()

Overrides:

toString in class Object

visitView

public void visitView(ViewDataVisitor viewDataVisitor)

Specified by:

visitView in interface ViewDataVisitable

expire

protected final void expire()

This method removes (expires) objects from the window and schedules a new callback for the time when the next oldest message would expire from the window.

stopView

public void stopView()

stop

public void stop()

Description copied from interface: StopCallback

Stops the underlying resources.

Specified by:

stop in interface StopCallback

stopSchedule

public void stopSchedule()

getViewFactory

public ViewFactory getViewFactory()

Specified by:

getViewFactory in interface GroupableView