com.espertech.esper.collection

Class TimeWindow

java.lang.Object

com.espertech.esper.collection.TimeWindow

All Implemented Interfaces:

Iterable

public final class TimeWindow
extends Object
implements Iterable

Container for events per time slot. The time is provided as long milliseconds by client classes. Events are for a specified timestamp and the implementation creates and adds the event to a slot for that timestamp. Events can be expired from the window via the expireEvents method when their timestamp is before (or less then) an expiry timestamp passed in. Expiry removes the event from the window. The window allows iteration through its contents.

It is assumed that the timestamp passed to the add method is ascending. The window is backed by a collection reflecting the timestamp order rather then any sorted map or linked hash map for performance reasons.

Constructor Summary

Constructors

Constructor and Description
TimeWindow(boolean isSupportRemoveStream) Ctor.

Method Summary

Modifier and Type	Method and Description
void	add(long timestamp, EventBean bean) Adds event to the time window for the specified timestamp.
void	adjust(long delta) Adjust expiry dates.
ArrayDeque<EventBean>	expireEvents(long expireBefore) Return and remove events in time-slots earlier (less) then the timestamp passed in, returning the list of events expired.
Long	getOldestTimestamp() Returns the oldest timestamp in the collection if there is at least one entry, else it returns null if the window is empty.
Map<EventBean,TimeWindowPair>	getReverseIndex() Returns the reverse index, for testing purposes.
ArrayDeque<TimeWindowPair>	getWindow()
boolean	isEmpty() Returns true if the window is currently empty.
Iterator<EventBean>	iterator() Returns event iterator.
void	remove(EventBean theEvent) Removes the event from the window, if remove stream handling is enabled.
void	setReverseIndex(Map<EventBean,TimeWindowPair> reverseIndex)
void	setWindow(ArrayDeque<TimeWindowPair> window, int size)
void	visitView(ViewDataVisitor viewDataVisitor, DataWindowViewFactory viewFactory)

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

Constructor Detail

TimeWindow

public TimeWindow(boolean isSupportRemoveStream)

Ctor.

Parameters:

isSupportRemoveStream - true to indicate the time window should support effective removal of events in the window based on the remove stream events received, or false to not accomodate removal at all

Method Detail

adjust

public void adjust(long delta)

Adjust expiry dates.

Parameters:

delta - delta to adjust for

add

public final void add(long timestamp,
                      EventBean bean)

Adds event to the time window for the specified timestamp.

Parameters:

timestamp - - the time slot for the event

bean - - event to add

remove

public final void remove(EventBean theEvent)

Removes the event from the window, if remove stream handling is enabled.

Parameters:

theEvent - to remove

expireEvents

public final ArrayDeque<EventBean> expireEvents(long expireBefore)

Return and remove events in time-slots earlier (less) then the timestamp passed in, returning the list of events expired.

Parameters:

expireBefore - is the timestamp from which on to keep events in the window

Returns:

a list of events expired and removed from the window, or null if none expired

iterator

public final Iterator<EventBean> iterator()

Returns event iterator.

Specified by:

iterator in interface Iterable

Returns:

iterator over events currently in window

getOldestTimestamp

public final Long getOldestTimestamp()

Returns the oldest timestamp in the collection if there is at least one entry, else it returns null if the window is empty.

Returns:

null if empty, oldest timestamp if not empty

isEmpty

public final boolean isEmpty()

Returns true if the window is currently empty.

Returns:

true if empty, false if not

getReverseIndex

public Map<EventBean,TimeWindowPair> getReverseIndex()

Returns the reverse index, for testing purposes.

Returns:

reverse index

getWindow

public ArrayDeque<TimeWindowPair> getWindow()

setWindow

public void setWindow(ArrayDeque<TimeWindowPair> window,
                      int size)

setReverseIndex

public void setReverseIndex(Map<EventBean,TimeWindowPair> reverseIndex)

visitView

public void visitView(ViewDataVisitor viewDataVisitor,
                      DataWindowViewFactory viewFactory)