Package ca.uqac.lif.cep.complex

Class RangeCep

java.lang.Object

ca.uqac.lif.cep.Processor

ca.uqac.lif.cep.SynchronousProcessor

ca.uqac.lif.cep.complex.RangeCep

All Implemented Interfaces:

ca.uqac.lif.cep.Contextualizable, ca.uqac.lif.cep.Duplicable, ca.uqac.lif.cep.DuplicableProcessor

public class RangeCep
extends ca.uqac.lif.cep.SynchronousProcessor

Creates complex events out of a range of simple events. The processor is parameterized by the following elements:

• A processor π_R outputting a stream of Boolean values, called the range processor. This processor signals the range of contiguous events of the input stream that should be taken into account in the construction of the complex event. Its expected behavior is to continually return ⊥ until the first event of the range is observed, then to output ⊤ for each event to be included in the range, and then to resume returning ⊥ forever once the range is over.
• An array of processors π₁, … π_n called the data processors. Each of these processors is fed the range of events identified by π_R, and only those events. The calculation done by the data processors is arbitrary.
• A function f called the complex event function. This function must be of arity n:1; it is called exactly once when the end of the range is reached. Its input arguments are the last event produced by each of the π_i on the event range; its output is the complex event created out of those values.

In addition, the processor may optionally allow restarts (using allowRestarts(boolean)). In this case, when a complex event is produced, π_R and all of the π_i are reset to their initial state, which makes it possible for a new complex event to be produced with the events received from this point on.

Author:

Sylvain Hallé

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static enum	RangeCep.State	The current state of the range, which is updated upon receiving each input event.

Nested classes/interfaces inherited from class ca.uqac.lif.cep.SynchronousProcessor

ca.uqac.lif.cep.SynchronousProcessor.InputPushable, ca.uqac.lif.cep.SynchronousProcessor.OutputPullable

Nested classes/interfaces inherited from class ca.uqac.lif.cep.Processor

ca.uqac.lif.cep.Processor.InternalProcessorState

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	m_allowRestarts	A flag that determines if more than one complex event can be produced (default: false).
protected final ca.uqac.lif.cep.functions.Function	m_complexEventFunction	The function that is called when the end of the range is reached, and which is used to create the complex output event.
protected boolean	m_contiguous	A flag that determines if the false event that marks the end of a range should count as the first event of a new range (i.e.
protected RangeCep.State	m_currentState	The current state of the range.
protected final ca.uqac.lif.cep.tmf.PushUnit[]	m_dataProcessors	An array of push units that evaluate the data processors.
protected boolean	m_includesLast	A flag that determines if the event that determines the end boundary of the range should be included (i.e.
protected final ca.uqac.lif.cep.tmf.PushUnit	m_range	A push unit that evaluates the range processor.

Fields inherited from class ca.uqac.lif.cep.SynchronousProcessor

m_inputPushables, m_outputPullables, m_tempQueue

Fields inherited from class ca.uqac.lif.cep.Processor

m_context, m_hasBeenNotifiedOfEndOfTrace, m_inputArity, m_inputPullables, m_inputQueues, m_notifiedEndOfTraceDownstream, m_outputArity, m_outputPushables, m_outputQueues, MAX_PULL_RETRIES, s_versionString

Constructor Summary

Constructors

Modifier	Constructor	Description
	RangeCep(ca.uqac.lif.cep.Processor range_processor, ca.uqac.lif.cep.Processor[] data_processors, ca.uqac.lif.cep.functions.Function ce_function)	Creates a new range complex event processor.
protected	RangeCep(ca.uqac.lif.cep.tmf.PushUnit range, ca.uqac.lif.cep.tmf.PushUnit[] data, ca.uqac.lif.cep.functions.Function ce_function)	Creates a new range complex event processor.

Method Summary

Modifier and Type	Method	Description
RangeCep	allowRestarts(boolean b)	Sets whether the processor is allowed to produce multiple successive complex events.
protected boolean	compute(Object[] inputs, Queue<Object[]> outputs)
RangeCep	duplicate(boolean with_state)
RangeCep	includesLast(boolean b)	Sets whether the event that determines the end boundary of the range should be included (i.e.
RangeCep	isContiguous(boolean b)	Sets whether the false event that marks the end of a range should count as the first event of a new range (i.e.
protected Object	produceComplexEvent()	Produces the complex output event out of the last event output by each data processor.
protected void	pushFront(Object[] inputs)	Pushes an event front to all data processors.
void	reset()

Methods inherited from class ca.uqac.lif.cep.SynchronousProcessor

getPullableOutput, getPushableInput

Methods inherited from class ca.uqac.lif.cep.Processor

allNotifiedEndOfTrace, allNull, copyInputQueue, copyOutputQueue, duplicate, duplicateInto, equals, getAt, getContext, getContext, getEmptyQueue, getId, getInputArity, getInputQueue, getInputType, getInputTypesFor, getOutputArity, getOutputQueue, getOutputType, getPullableInput, getPullableOutput, getPushableInput, getPushableOutput, hashCode, leftShift, newContext, onEndOfTrace, or, or, or, printState, readState, rightShift, setContext, setContext, setPullableInput, setPushableOutput, start, startAll, stop, stopAll

Methods inherited from class java.lang.Object

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

Field Details

m_currentState

protected RangeCep.State m_currentState

The current state of the range.

m_range

protected final ca.uqac.lif.cep.tmf.PushUnit m_range

A push unit that evaluates the range processor.

m_dataProcessors

protected final ca.uqac.lif.cep.tmf.PushUnit[] m_dataProcessors

An array of push units that evaluate the data processors.

m_complexEventFunction

protected final ca.uqac.lif.cep.functions.Function m_complexEventFunction

The function that is called when the end of the range is reached, and which is used to create the complex output event.

m_allowRestarts

protected boolean m_allowRestarts

A flag that determines if more than one complex event can be produced (default: false).

m_includesLast

protected boolean m_includesLast

A flag that determines if the event that determines the end boundary of the range should be included (i.e. pushed) a part of the complex event (default: false).

m_contiguous

protected boolean m_contiguous

A flag that determines if the false event that marks the end of a range should count as the first event of a new range (i.e. complex events are contiguous).

Constructor Details

RangeCep

public RangeCep(ca.uqac.lif.cep.Processor range_processor,
 ca.uqac.lif.cep.Processor[] data_processors,
 ca.uqac.lif.cep.functions.Function ce_function)

Creates a new range complex event processor.

Parameters:

range_processor - The processor used to determine the range of events to include in the complex event

data_processors - An array of processors evaluated on the range of events

ce_function - The function used to create the complex output event out of the values produced by each data processor

RangeCep

protected RangeCep(ca.uqac.lif.cep.tmf.PushUnit range,
 ca.uqac.lif.cep.tmf.PushUnit[] data,
 ca.uqac.lif.cep.functions.Function ce_function)

Creates a new range complex event processor. This constructor is only called internally by duplicate(boolean).

Parameters:

range - A push unit that evaluates the range processor

data - An array of push units that evaluate the data processors

ce_function - The function used to create the complex output event out of the values produced by each data processor

Method Details

allowRestarts

public RangeCep allowRestarts(boolean b)

Sets whether the processor is allowed to produce multiple successive complex events.

Parameters:

b - Set to true to allow restarts, false otherwise

Returns:

This processor

includesLast

public RangeCep includesLast(boolean b)

Sets whether the event that determines the end boundary of the range should be included (i.e. pushed) a part of the complex event.

Parameters:

b - Set to true to include this last event, false otherwise

Returns:

This processor

isContiguous

public RangeCep isContiguous(boolean b)

Sets whether the false event that marks the end of a range should count as the first event of a new range (i.e. complex events are contiguous).

Parameters:

b - Set to true to make complex events contiguous, false otherwise

Returns:

This processor

compute

protected boolean compute(Object[] inputs,
 Queue<Object[]> outputs)

Specified by:

compute in class ca.uqac.lif.cep.SynchronousProcessor

pushFront

protected void pushFront(Object[] inputs)

Pushes an event front to all data processors.

Parameters:

inputs - The event front

produceComplexEvent

protected Object produceComplexEvent()

Produces the complex output event out of the last event output by each data processor. This is done by fetching all these events in an array and then calling the complex event function.

Returns:

The complex output event

reset

public void reset()

Overrides:

reset in class ca.uqac.lif.cep.Processor

duplicate

public RangeCep duplicate(boolean with_state)

Specified by:

duplicate in interface ca.uqac.lif.cep.Duplicable

Specified by:

duplicate in class ca.uqac.lif.cep.Processor