Abstract base class for the filter hierarchy. More...

#include <EC_Filter.h>

Inheritance diagram for TAO_EC_Filter:

Collaboration diagram for TAO_EC_Filter:

Public Types
typedef TAO_EC_Filter *	value_type

typedef TAO_EC_Filter *const	const_value_type

typedef const_value_type *	ChildrenIterator

Public Member Functions
	TAO_EC_Filter (void)
	constructor... More...

virtual	~TAO_EC_Filter (void)
	destructor... More...

TAO_EC_Filter *	parent (void) const
	Obtain the parent of this filter. More...

void	adopt_child (TAO_EC_Filter *child)
	Become the parent of child. More...

virtual ChildrenIterator	begin (void) const

virtual ChildrenIterator	end (void) const

virtual int	size (void) const

virtual int	filter (const RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info)=0

virtual int	filter_nocopy (RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info)=0

virtual void	push (const RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info)=0

virtual void	push_nocopy (RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info)=0

virtual void	clear (void)=0

virtual CORBA::ULong	max_event_size (void) const =0
	Returns the maximum size of the events pushed by this filter. More...

virtual int	can_match (const RtecEventComm::EventHeader &header) const =0

virtual int	add_dependencies (const RtecEventComm::EventHeader &header, const TAO_EC_QOS_Info &qos_info)=0

virtual void	get_qos_info (TAO_EC_QOS_Info &qos_info)

Static Public Member Functions
static int	matches (const RtecEventComm::EventHeader &rhs, const RtecEventComm::EventHeader &lhs)

Private Attributes
TAO_EC_Filter *	parent_
	The parent... More...

Detailed Description

Abstract base class for the filter hierarchy.

The per-consumer filtering mechanisms. The EC needs to filter data passed to the consumers, so it can correctly satisfy its subscription requirements. This filtering can include correlations, sequences, timeouts, etc. each consumer can request different filtering criteria. Different filtering objects are associated with each consumer, the filters are organized in a hierarchical structure, corresponding to the subscription "expression" that the events must satisfy. The hierarchy is constructed using the "Builder" pattern.

Memory Management

It does not assume ownership of its parent.

Member Typedef Documentation

typedef const_value_type* TAO_EC_Filter::ChildrenIterator

typedef TAO_EC_Filter* const TAO_EC_Filter::const_value_type

typedef TAO_EC_Filter* TAO_EC_Filter::value_type

Constructor & Destructor Documentation

TAO_EC_Filter::TAO_EC_Filter ( void )

constructor...

TAO_EC_Filter::~TAO_EC_Filter ( void )

virtual

destructor...

Member Function Documentation

virtual int TAO_EC_Filter::add_dependencies	(	const RtecEventComm::EventHeader &	header,
		const TAO_EC_QOS_Info &	qos_info
	)

pure virtual

This is used for computing the scheduling dependencies:

Leaf filters check if the header could be matched, similar to the can_match() method; if it does they return 1, and 0 otherwise. Intermediate nodes always return 0.

This is used to build precise dependencies between the suppliers and the leaf of the filters that accept that event. Notice that only the nodes doing scheduling recurse through the list, so in configurations that do no require scheduling the recursion stops fairly soon.

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

void TAO_EC_Filter::adopt_child ( TAO_EC_Filter * child )

Become the parent of child.

TAO_EC_Filter::ChildrenIterator TAO_EC_Filter::begin ( void ) const

virtual

STL-like iterators Filters follow the Composite pattern. All filters expose the same interface as if they all had children, but for simple filters the iterators return an empty range.

Reimplemented in TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, and TAO_EC_Negation_Filter.

virtual int TAO_EC_Filter::can_match ( const RtecEventComm::EventHeader & header ) const

pure virtual

Returns 0 if an event with that header could never be accepted. This can used by the suppliers to filter out consumers that couldn't possibly be interested in their events. The rt_info and

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

virtual void TAO_EC_Filter::clear ( void )

pure virtual

Clear any saved state, must reset and assume no events have been received.

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

TAO_EC_Filter::ChildrenIterator TAO_EC_Filter::end ( void ) const

virtual

Reimplemented in TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, and TAO_EC_Negation_Filter.

virtual int TAO_EC_Filter::filter	(	const RtecEventComm::EventSet &	event,
		TAO_EC_QOS_Info &	qos_info
	)

pure virtual

Filter this event, returns 1 if the event is accepted, 0 otherwise. Notice that there are two versions of the method, if the event is not const then filter can take ownership of the event.

Attention: There seems to be a disparity in interfaces: Supplier always push event sets of size 1 to the EC_ProxyPushSupplier, and EC_Filters do not implement handling of sets of more than 1 event. Then, why is this not enforced by the interface by having EC_ProxyPushSupplier take an event rather than a set?

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

virtual int TAO_EC_Filter::filter_nocopy	(	RtecEventComm::EventSet &	event,
		TAO_EC_QOS_Info &	qos_info
	)

pure virtual

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

void TAO_EC_Filter::get_qos_info ( TAO_EC_QOS_Info & qos_info )

virtual

Obtain the QOS information for this filter, the default implementation returns an invalid QOS. Only the filters that support scheduling information implement this method.

Returns: Returns 0 on success and -1 on failure

Reimplemented in TAO_EC_Kokyu_Filter, and TAO_EC_Sched_Filter.

int TAO_EC_Filter::matches	(	const RtecEventComm::EventHeader &	rhs,
		const RtecEventComm::EventHeader &	lhs
	)

static

Matches two event headers.

Todo:: Should we strategize the algorithm used to match headers?

virtual CORBA::ULong TAO_EC_Filter::max_event_size ( void ) const

pure virtual

Returns the maximum size of the events pushed by this filter.

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.

TAO_EC_Filter * TAO_EC_Filter::parent ( void ) const

Obtain the parent of this filter.

virtual void TAO_EC_Filter::push	(	const RtecEventComm::EventSet &	event,
		TAO_EC_QOS_Info &	qos_info
	)

pure virtual

This is called by the children when they accept an event and which to pass it up. Notice that there are two versions of the method, if the event is not const then filter can take ownership of the event.

Implemented in TAO_EC_Null_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Bitmask_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Disjunction_Filter, TAO_EC_And_Filter, TAO_EC_Negation_Filter, and TAO_EC_Type_Filter.