com.espertech.esper.view.window
Class ExpressionViewFactoryBase

java.lang.Object
  com.espertech.esper.view.window.ExpressionViewFactoryBase

All Implemented Interfaces:

DataWindowViewFactory, DataWindowViewWithPrevious, ViewFactory

Direct Known Subclasses:

ExpressionBatchViewFactory, ExpressionWindowViewFactory

public abstract class ExpressionViewFactoryBase
extends java.lang.Object
implements DataWindowViewFactory, DataWindowViewWithPrevious

Base factory for expression-based window and batch view.

Field Summary

protected AggregationServiceFactoryDesc	aggregationServiceFactoryDesc
protected EventType	builtinMapType
protected ExprNode	expiryExpression
protected java.util.Set<java.lang.String>	variableNames

Constructor Summary

ExpressionViewFactoryBase()

Method Summary

void	attach(EventType parentEventType, StatementContext statementContext, ViewFactory optionalParentFactory, java.util.List<ViewFactory> parentViewFactories) Attaches the factory to a parent event type such that the factory can validate attach requirements and determine an event type for resulting views.
boolean	canReuse(View view) Determines if the given view could be used instead of creating a new view, requires the view factory to compare view type, parameters and other capabilities provided.
EventType	getBuiltinMapType()
EventType	getEventType() Returns the event type that the view that is created by the view factory would create for events posted by the view.

Methods inherited from class java.lang.Object

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

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

getViewName, makeView, setViewParameters

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

makePreviousGetter

Field Detail

expiryExpression

protected ExprNode expiryExpression

variableNames

protected java.util.Set<java.lang.String> variableNames

aggregationServiceFactoryDesc

protected AggregationServiceFactoryDesc aggregationServiceFactoryDesc

builtinMapType

protected EventType builtinMapType

Constructor Detail

ExpressionViewFactoryBase

public ExpressionViewFactoryBase()

Method Detail

attach

public void attach(EventType parentEventType,
                   StatementContext statementContext,
                   ViewFactory optionalParentFactory,
                   java.util.List<ViewFactory> parentViewFactories)
            throws ViewParameterException

Description copied from interface: ViewFactory

Attaches the factory to a parent event type such that the factory can validate attach requirements and determine an event type for resulting views.

Specified by:

attach in interface ViewFactory

Parameters:

parentEventType - is the parent event stream's or view factory's event type

statementContext - contains the services needed for creating a new event type

optionalParentFactory - is null when there is no parent view factory, or contains the parent view factory

parentViewFactories - is a list of all the parent view factories or empty list if there are none

Throws:

ViewParameterException - is thrown to indicate that this view factories's view would not play with the parent view factories view

getEventType

public EventType getEventType()

Description copied from interface: ViewFactory

Returns the event type that the view that is created by the view factory would create for events posted by the view.

Specified by:

getEventType in interface ViewFactory

Returns:

event type of view's created by the view factory

canReuse

public boolean canReuse(View view)

Description copied from interface: ViewFactory

Determines if the given view could be used instead of creating a new view, requires the view factory to compare view type, parameters and other capabilities provided.

Specified by:

canReuse in interface ViewFactory

Parameters:

view - is the candidate view to compare to

Returns:

true if the given view can be reused instead of creating a new view, or false to indicate the view is not right for reuse

getBuiltinMapType

public EventType getBuiltinMapType()