net.esper.view.ext
Class TimeOrderView

java.lang.Object
  extended by net.esper.view.ViewSupport
      extended by net.esper.view.ext.TimeOrderView
All Implemented Interfaces:
Iterable<EventBean>, CloneableView, DataWindowView, EventCollection, View, Viewable

public final class TimeOrderView
extends ViewSupport
implements DataWindowView, CloneableView

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 inherited from class net.esper.view.ViewSupport
parent
 
Constructor Summary
TimeOrderView(StatementContext statementContext, TimeOrderViewFactory timeOrderViewFactory, String timestampFieldName, long intervalSize, IStreamTimeOrderRandomAccess optionalSortedRandomAccess, boolean isRemoveStreamHandling)
          Ctor.
 
Method Summary
 View cloneView(StatementContext statementContext)
          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.
 long getIntervalSize()
          Returns the time interval size.
protected  IStreamTimeOrderRandomAccess getOptionalSortedRandomAccess()
          Returns the friend handling the random access, cal be null if not required.
 String getTimestampFieldName()
          Returns the timestamp property name.
 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 setParent(Viewable parent)
          Called when the View is added to a Viewable object.
 String toString()
           
 void update(EventBean[] newData, EventBean[] oldData)
          Notify that data has been added or removed from the Viewable parent.
 
Methods inherited from class net.esper.view.ViewSupport
addView, dumpChildViews, dumpUpdateParams, findDescendent, getParent, getViews, hasViews, removeView, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface net.esper.view.View
getParent
 
Methods inherited from interface net.esper.view.Viewable
addView, getViews, hasViews, removeView
 

Constructor Detail

TimeOrderView

public TimeOrderView(StatementContext statementContext,
                     TimeOrderViewFactory timeOrderViewFactory,
                     String timestampFieldName,
                     long intervalSize,
                     IStreamTimeOrderRandomAccess optionalSortedRandomAccess,
                     boolean isRemoveStreamHandling)
Ctor.

Parameters:
optionalSortedRandomAccess - is the friend class handling the random access, if required by expressions
timeOrderViewFactory - for copying this view in a group-by
statementContext - the statement context
timestampFieldName - the property name of the event supplying timestamp values
intervalSize - the interval time length
isRemoveStreamHandling - if the view must handle the remove stream of parent views
Method Detail

setParent

public void setParent(Viewable parent)
Description copied from interface: View
Called when the View is added to a Viewable object.

Specified by:
setParent in interface View
Overrides:
setParent in class ViewSupport
Parameters:
parent - is the parent that this view is a child of

getTimestampFieldName

public String getTimestampFieldName()
Returns the timestamp property name.

Returns:
property name supplying timestamp values

getIntervalSize

public long getIntervalSize()
Returns the time interval size.

Returns:
interval size

getOptionalSortedRandomAccess

protected IStreamTimeOrderRandomAccess getOptionalSortedRandomAccess()
Returns the friend handling the random access, cal be null if not required.

Returns:
random accessor to sort window contents

cloneView

public View cloneView(StatementContext statementContext)
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
Parameters:
statementContext - is services for the view
Returns:
duplicated 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

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 Iterable<EventBean>
Specified by:
iterator in interface EventCollection
Returns:
an iterator which will go through all current elements in the collection.

toString

public final String toString()
Overrides:
toString in class Object

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.


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