TAO_EC_Filter Class Reference

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

#include <EC_Filter.h>

Inheritance diagram for TAO_EC_Filter:

[legend]Collaboration diagram for TAO_EC_Filter:

[legend]List of all members.


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...
virtual	~TAO_EC_Filter (void)
	destructor...
TAO_EC_Filter *	parent (void) const
	Obtain the parent of this filter.
void	adopt_child (TAO_EC_Filter *child)
	Become the parent of child.
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 ACE_ENV_ARG_DECL)=0
virtual int	filter_nocopy (RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL)=0
virtual void	push (const RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL)=0
virtual void	push_nocopy (RtecEventComm::EventSet &event, TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL)=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.
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 ACE_ENV_ARG_DECL)=0
virtual void	get_qos_info (TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL)
Static Public Member Functions
int	matches (const RtecEventComm::EventHeader &rhs, const RtecEventComm::EventHeader &lhs)
Private Attributes
TAO_EC_Filter *	parent_
	The parent...

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

ACE_INLINE 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 ACE_ENV_ARG_DECL

) [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_And_Filter, TAO_EC_Bitmask_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Disjunction_Filter, TAO_EC_Null_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Negation_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Sched_Filter, TAO_EC_Timeout_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_And_Filter, TAO_EC_Bitmask_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Disjunction_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Negation_Filter, and TAO_EC_Sched_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_And_Filter, TAO_EC_Bitmask_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Disjunction_Filter, TAO_EC_Null_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Negation_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Sched_Filter, TAO_EC_Timeout_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_And_Filter, TAO_EC_Bitmask_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Disjunction_Filter, TAO_EC_Null_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Negation_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, and TAO_EC_Type_Filter.

TAO_EC_Filter::ChildrenIterator TAO_EC_Filter::end ( void ) const [virtual]

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

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

TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL

) [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_And_Filter, TAO_EC_Bitmask_Filter, TAO_EC_Conjunction_Filter, TAO_EC_Disjunction_Filter, TAO_EC_Null_Filter, TAO_EC_Kokyu_Filter, TAO_EC_Masked_Type_Filter, TAO_EC_Negation_Filter, TAO_EC_ProxyPushSupplier, TAO_EC_Sched_Filter, TAO_EC_Timeout_Filter, and TAO_EC_Type_Filter.

virtual int TAO_EC_Filter::filter_nocopy ( RtecEventComm::EventSet & event,

TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL

) [pure virtual]

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

void TAO_EC_Filter::get_qos_info ( TAO_EC_QOS_Info &qos_info ACE_ENV_ARG_DECL ) [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.

ACE_INLINE 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?