Package com.streambase.liveview.client

Class LiveResult

java.lang.Object

com.streambase.liveview.client.LiveResult

All Implemented Interfaces:

QueryListener, EventListener

public class LiveResult
extends Object
implements QueryListener

A live result is a QueryListener the receives and maintains a local copy of tuples. Methods exists to retrieve the current list of tuples maintained locally. The live results can also be constructed with a nested QueryListener. In this mode the live result will propagate events it received to the nested listener. It will also modify update and remove events to include the old or removed tuple (in addition to the new tuple.)

Constructor Summary

Constructors

Constructor	Description
LiveResult()	Construct a LiveResult that will maintain the list of tuples for you which you can query at your leisure.
LiveResult(QueryListener listener)	Contruct a LiveResult that will maintain the tuples for you, plus you can also be informed of all the events.

Method Summary

Modifier and Type	Method	Description
void	aggMarkBegin(BeginAggMarkEvent event)	Event to indicate that the set of aggregation results may be changing so some results may be from an older generation while other may be from a newer one.
void	aggMarkEnd(EndAggMarkEvent event)	Event to indicate that the set of aggregation results since the last aggMarkBegin event are now consistent and will not change until the next aggMarkBegin.
void	deleteBegin(BeginDeleteEvent event)	Event to indicate the start of delete query.
void	deleteEnd(EndDeleteEvent event)	Event to indicate the delete query is complete.
void	exceptionRaised(QueryExceptionEvent event)	Event when an exception occurs during the query.
protected Long	getKeyForEvent(AbstractTupleEvent event, boolean remove)
protected Long	getKeyFromEvent(AbstractTupleEvent event)
Tuple	getTuple(KeyValue keyValue)	Get a tuple from the KeyValue obtained from an Event.
final Collection<Tuple>	getTuples()	Retrieves the current tuples in the result.
final Collection<Tuple>	getTuples(boolean waitForSnapshot)	Retrieves the current tuples in the result
final boolean	isEmpty()	Is the result empty
boolean	isSnapshotComplete()	Retreives whether or not the LiveResult is up to date.
void	queryClosed(QueryClosedEvent event)	Event when a query being listened to is closed.
void	setTimeout(int ms)	setTimeout limits the amount of time to wait for the snapshot to complete.
final int	size()	The size of the result
void	snapshotBegin(BeginSnapshotEvent event)	Event to indicate the start of the result snapshot.
void	snapshotEnd(EndSnapshotEvent event)	Event to indicate the query snapshot is complete.
void	tupleAdded(TupleAddedEvent event)	Event when a new tuple is added to the result.
void	tupleRemoved(TupleRemovedEvent event)	Event when an existing tuple is removed from the result.
void	tupleUpdated(TupleUpdatedEvent event)	Event when an existing tuple in the result is updated.
final void	waitForSnapshot()	Blocking call that waits for the query snapshot to complete.

Methods inherited from class java.lang.Object

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

Constructor Details

LiveResult

public LiveResult(QueryListener listener)

Contruct a LiveResult that will maintain the tuples for you, plus you can also be informed of all the events. All events will be passed on to your listener. However, the update events will be populated with a complete old and new tuples. (Without the LiveResult, then update events only have the

Parameters:

listener - The listener to dispatch events to when changes occur on this LiveResult

LiveResult

public LiveResult()

Construct a LiveResult that will maintain the list of tuples for you which you can query at your leisure.

Method Details

setTimeout

public void setTimeout(int ms)

setTimeout limits the amount of time to wait for the snapshot to complete.

Parameters:

ms - - number of milliseconds to wait before abandoning waiting for snapshot complete.

Since:

1.4.1

isEmpty

public final boolean isEmpty()

Is the result empty

Returns:

true is the result is empty

size

public final int size()

The size of the result

Returns:

the size

getTuple

public Tuple getTuple(KeyValue keyValue)

Get a tuple from the KeyValue obtained from an Event. Note that this will return null if the tuple is not in the list of tuples, that is, before it has been added or after it has been removed.

Parameters:

keyValue - of type KeyValue.

Returns:

Tuple.

getTuples

public final Collection<Tuple> getTuples()

Retrieves the current tuples in the result.

Returns:

the collection of tuples in the result.

getTuples

public final Collection<Tuple> getTuples(boolean waitForSnapshot)

Retrieves the current tuples in the result

Parameters:

waitForSnapshot - waits for the query snapshot to complete before returning from the call

Returns:

the collection of tuples in the result

waitForSnapshot

public final void waitForSnapshot()

Blocking call that waits for the query snapshot to complete.

tupleAdded

public void tupleAdded(TupleAddedEvent event)

Event when a new tuple is added to the result.

Specified by:

tupleAdded in interface QueryListener

Parameters:

event - add event

Throws:

TupleException

getKeyFromEvent

protected Long getKeyFromEvent(AbstractTupleEvent event)

getKeyForEvent

protected Long getKeyForEvent(AbstractTupleEvent event,
 boolean remove)

tupleUpdated

public void tupleUpdated(TupleUpdatedEvent event)

Event when an existing tuple in the result is updated.

Specified by:

tupleUpdated in interface QueryListener

Parameters:

event - update event

tupleRemoved

public void tupleRemoved(TupleRemovedEvent event)

Event when an existing tuple is removed from the result.

Specified by:

tupleRemoved in interface QueryListener

Parameters:

event - remove event

snapshotBegin

public void snapshotBegin(BeginSnapshotEvent event)

Event to indicate the start of the result snapshot. This is the first method called when a query starts returning results, but this method is also called to indicate a reset (a complete restart of the query.)

Specified by:

snapshotBegin in interface QueryListener

Parameters:

event - snapshot begin

snapshotEnd

public void snapshotEnd(EndSnapshotEvent event)

Event to indicate the query snapshot is complete.

Specified by:

snapshotEnd in interface QueryListener

Parameters:

event - snapshot end

exceptionRaised

public void exceptionRaised(QueryExceptionEvent event)

Event when an exception occurs during the query. Since 1.3, reaching the row limit is considered an exception.

Specified by:

exceptionRaised in interface QueryListener

Parameters:

event - exception event

queryClosed

public void queryClosed(QueryClosedEvent event)

Event when a query being listened to is closed.

Specified by:

queryClosed in interface QueryListener

Parameters:

event - query closed event

deleteBegin

public void deleteBegin(BeginDeleteEvent event)

Description copied from interface: QueryListener

Event to indicate the start of delete query.

Specified by:

deleteBegin in interface QueryListener

Parameters:

event - delete begin

deleteEnd

public void deleteEnd(EndDeleteEvent event)

Description copied from interface: QueryListener

Event to indicate the delete query is complete.

Specified by:

deleteEnd in interface QueryListener

Parameters:

event - delete end

aggMarkEnd

public void aggMarkEnd(EndAggMarkEvent event)

Description copied from interface: QueryListener

Event to indicate that the set of aggregation results since the last aggMarkBegin event are now consistent and will not change until the next aggMarkBegin.

Specified by:

aggMarkEnd in interface QueryListener

Parameters:

event - the EndAggMarkEvent

aggMarkBegin

public void aggMarkBegin(BeginAggMarkEvent event)

Description copied from interface: QueryListener

Event to indicate that the set of aggregation results may be changing so some results may be from an older generation while other may be from a newer one.

Specified by:

aggMarkBegin in interface QueryListener

Parameters:

event - the BeginAggMarkEvent

isSnapshotComplete

public boolean isSnapshotComplete()

Retreives whether or not the LiveResult is up to date.

Returns:

true if the LiveResult is up to date.