com.espertech.esper.epl.join.table
Class PropertyIndexedEventTable

java.lang.Object
  com.espertech.esper.epl.join.table.PropertyIndexedEventTable

All Implemented Interfaces:

EventTable, java.lang.Iterable<EventBean>

Direct Known Subclasses:

PropertyIndexedEventTableCoerceAdd, PropertyIndexedEventTableUnique

public class PropertyIndexedEventTable
extends java.lang.Object
implements EventTable

Index that organizes events by the event property values into hash buckets. Based on a HashMap with MultiKeyUntyped keys that store the property values. Takes a list of property names as parameter. Doesn't care which event type the events have as long as the properties exist. If the same event is added twice, the class throws an exception on add.

Field Summary

protected EventTableOrganization	organization
protected EventPropertyGetter[]	propertyGetters
protected java.util.Map<MultiKeyUntyped,java.util.Set<EventBean>>	propertyIndex

Constructor Summary

PropertyIndexedEventTable(EventPropertyGetter[] propertyGetters, EventTableOrganization organization)

Method Summary

void	add(EventBean theEvent) Add event to table.
void	add(EventBean[] events) Add an array of events.
void	addRemove(EventBean[] newData, EventBean[] oldData) Add and remove events from table.
void	clear() Clear out index.
java.lang.Object	getIndex() Return the index object itself, or an object-array for multiple index structures.
protected MultiKeyUntyped	getMultiKey(EventBean theEvent) Determine multikey for index access.
java.lang.Integer	getNumberOfEvents() If the number of events is readily available, an implementation will return that number or it may return null to indicate that the count is not readily available.
int	getNumKeys() If the index retains events using some key-based organization this returns the number of keys, and may return null to indicate that either the number of keys is not available or costly to obtain.
EventTableOrganization	getOrganization()
boolean	isEmpty() Returns true if the index is empty, or false if not
java.util.Iterator<EventBean>	iterator() Returns an iterator over events in the table.
java.util.Set<EventBean>	lookup(java.lang.Object[] keys) Returns the set of events that have the same property value as the given event.
void	remove(EventBean theEvent) Remove event from table.
void	remove(EventBean[] events) Remove events.
java.lang.String	toQueryPlan()

Methods inherited from class java.lang.Object

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

Field Detail

propertyGetters

protected final EventPropertyGetter[] propertyGetters

organization

protected final EventTableOrganization organization

propertyIndex

protected final java.util.Map<MultiKeyUntyped,java.util.Set<EventBean>> propertyIndex

Constructor Detail

PropertyIndexedEventTable

public PropertyIndexedEventTable(EventPropertyGetter[] propertyGetters,
                                 EventTableOrganization organization)

Method Detail

getMultiKey

protected MultiKeyUntyped getMultiKey(EventBean theEvent)

Determine multikey for index access.

Parameters:

theEvent - to get properties from for key

Returns:

multi key

addRemove

public void addRemove(EventBean[] newData,
                      EventBean[] oldData)

Description copied from interface: EventTable

Add and remove events from table.

It is up to the index to decide whether to add first and then remove, or whether to remove and then add.

It is important to note that a given event can be in both the removed and the added events. This means that unique indexes probably need to remove first and then add. Most other non-unique indexes will add first and then remove since the an event can be both in the add and the remove stream.

Specified by:

addRemove in interface EventTable

Parameters:

newData - to add

oldData - to remove

add

public void add(EventBean[] events)

Add an array of events. Same event instance is not added twice. Event properties should be immutable. Allow null passed instead of an empty array.

Specified by:

add in interface EventTable

Parameters:

events - to add

Throws:

java.lang.IllegalArgumentException - if the event was already existed in the index

remove

public void remove(EventBean[] events)

Remove events.

Specified by:

remove in interface EventTable

Parameters:

events - to be removed, can be null instead of an empty array.

Throws:

java.lang.IllegalArgumentException - when the event could not be removed as its not in the index

lookup

public java.util.Set<EventBean> lookup(java.lang.Object[] keys)

Returns the set of events that have the same property value as the given event.

Parameters:

keys - to compare against

Returns:

set of events with property value, or null if none found (never returns zero-sized set)

add

public void add(EventBean theEvent)

Description copied from interface: EventTable

Add event to table.

Specified by:

add in interface EventTable

Parameters:

theEvent - to add

remove

public void remove(EventBean theEvent)

Description copied from interface: EventTable

Remove event from table.

Specified by:

remove in interface EventTable

Parameters:

theEvent - to remove

isEmpty

public boolean isEmpty()

Description copied from interface: EventTable

Returns true if the index is empty, or false if not

Specified by:

isEmpty in interface EventTable

Returns:

true for empty index

iterator

public java.util.Iterator<EventBean> iterator()

Description copied from interface: EventTable

Returns an iterator over events in the table.

Specified by:

iterator in interface EventTable

Specified by:

iterator in interface java.lang.Iterable<EventBean>

Returns:

table iterator

clear

public void clear()

Description copied from interface: EventTable

Clear out index.

Specified by:

clear in interface EventTable

toQueryPlan

public java.lang.String toQueryPlan()

Specified by:

toQueryPlan in interface EventTable

getNumberOfEvents

public java.lang.Integer getNumberOfEvents()

Description copied from interface: EventTable

If the number of events is readily available, an implementation will return that number or it may return null to indicate that the count is not readily available.

Specified by:

getNumberOfEvents in interface EventTable

Returns:

number of events

getNumKeys

public int getNumKeys()

Description copied from interface: EventTable

If the index retains events using some key-based organization this returns the number of keys, and may return null to indicate that either the number of keys is not available or costly to obtain.

The number returned can be an estimate and may not be accurate.

Specified by:

getNumKeys in interface EventTable

Returns:

number of events

getIndex

public java.lang.Object getIndex()

Description copied from interface: EventTable

Return the index object itself, or an object-array for multiple index structures.

May return null if the information is not readily available, i.e. externally maintained index

Specified by:

getIndex in interface EventTable

Returns:

index object

getOrganization

public EventTableOrganization getOrganization()

Specified by:

getOrganization in interface EventTable