rti::sub::TopicQuery Class Reference

<<extension>> <<reference-type>> Allows a dds::sub::DataReader to query the sample cache of its matching dds::pub::DataWriters. More...

#include <rti/sub/TopicQuery.hpp>

Inheritance diagram for rti::sub::TopicQuery:

Public Member Functions
	TopicQuery (dds::sub::AnyDataReader reader, const TopicQuerySelection &selection)
	Creates a TopicQuery for a given DataReader. More...
void	close ()
	Deletes and cancels this TopicQuery. More...
const rti::core::Guid	guid () const
	Gets the TopicQuery GUID. More...
bool	closed () const
	Indicates whether this TopicQuery has been closed with close(). More...
dds::sub::AnyDataReader	datareader () const
	Gets the DataReader associated to this TopicQuery. More...

Static Public Member Functions
static TopicQuery	UseReaderContentFilter (dds::sub::AnyDataReader reader)
	Creates a TopicQuery with the same filter as this reader's ContentFilteredTopic. More...
static TopicQuery	SelectAll (dds::sub::AnyDataReader reader)
	Creates a TopicQuery that requests all the samples in the DataWriters' cache. More...

Related Functions
(Note that these are not member functions.)
TopicQuery	find_topic_query (dds::sub::AnyDataReader datareader, const rti::core::Guid &guid)
	Looks up a TopicQuery by its GUID. More...

Detailed Description

<<extension>> <<reference-type>> Allows a dds::sub::DataReader to query the sample cache of its matching dds::pub::DataWriters.

Note

A TopicQuery provides all the functions of a <<reference-type>>, including close() and retain().

You can create a TopicQuery for a DataReader with the constructor that receives a TopicQuerySelection or with the following static member functions:

• TopicQuery::UseReaderContentFilter
• TopicQuery::SelectAll

As a <<reference-type>>, a TopicQuery will be deleted when all references to it go out of scope or after calling close(). The middleware will notify the deletion of a TopicQuery to the DataWriters. See close() for more details.

Constructor & Destructor Documentation

TopicQuery()

rti::sub::TopicQuery::TopicQuery ( dds::sub::AnyDataReader  reader, const TopicQuerySelection &  selection  )

inline

Creates a TopicQuery for a given DataReader.

The resulting TopicQuery will propagate to the matching DataWriters right after creating if the reader is enabled. Otherwise it will propagate after enabling the reader.

Any late-joining DataWriter matching with the DataReader will also receive the query.

Parameters

reader	The DataReader that will query and receive the requested samples
selection	Selects which samples the matching DataWriters will provide.

There are two special kinds of TopicQueries, created with the static member functions UseReaderContentFilter() and SelectAll().

Member Function Documentation

close()

void rti::sub::TopicQuery::close ( )

inline

Deletes and cancels this TopicQuery.

This is a explicit deletion, which otherwise would occur when all references to this TopicQuery go out of scope.

After deleting a TopicQuery new DataWriters won't discover it and existing DataWriters currently publishing cached samples may stop before delivering all of them.

guid()

const rti::core::Guid rti::sub::TopicQuery::guid ( ) const

inline

Gets the TopicQuery GUID.

See also

rti::sub::find_topic_query()

closed()

bool rti::sub::TopicQuery::closed ( ) const

inline

Indicates whether this TopicQuery has been closed with close().

datareader()

dds::sub::AnyDataReader rti::sub::TopicQuery::datareader ( ) const

inline

Gets the DataReader associated to this TopicQuery.

References rti::sub::find_topic_query().

UseReaderContentFilter()

static TopicQuery rti::sub::TopicQuery::UseReaderContentFilter ( dds::sub::AnyDataReader  reader )

static

Creates a TopicQuery with the same filter as this reader's ContentFilteredTopic.

If the reader doesn't use a dds::topic::ContentFilteredTopic, this TopicQuery behaves as TopicQuery::SelectAll().

SelectAll()

static TopicQuery rti::sub::TopicQuery::SelectAll ( dds::sub::AnyDataReader  reader )

static

Creates a TopicQuery that requests all the samples in the DataWriters' cache.

Friends And Related Function Documentation

find_topic_query()

TopicQuery find_topic_query ( dds::sub::AnyDataReader  datareader, const rti::core::Guid &  guid  )

related

Looks up a TopicQuery by its GUID.

Parameters

datareader	The DataReader used to create the TopicQuery
guid	The TopicQuery's GUID

Returns

The TopicQuery if it exists or a dds::core::null reference otherwise.

See also

rti::sub::TopicQuery::guid()