The DataReader entity allows the application to subscribe to and read data. More...

Inheritance diagram for DDS::DataReader:

Public Member Functions
InstanceHandle_t	get_instance_handle ()
	This operation returns the InstanceHandle_t that identifies the DataReader.

StatusMask	get_status_changes ()
	This returns the list of triggered communication statuses in the DataReader. More...

ReturnCode_t	enable ()
	Enables the DataReader. More...

StatusCondition *	get_statuscondition ()
	Gets the StatusCondition associated with this Entity. NOTE: The entity maintains ownership of the statuscondition, and it remains valid only as long as the Entity is valid. Destroying the Entity also destroys the status condition.

ReadCondition *	create_readcondition (SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	Creates a ReadCondition that is associated with this DataReader. More...

ReturnCode_t	delete_readcondition (ReadCondition *a_condition)
	Destroys a ReadCondition (or QueryCondition). More...

ReturnCode_t	delete_contained_entities ()
	This operation deletes all the ReadCondition and QueryCondition objects previously created by means of the DataReader_create_readcondition() and DataReader_create_querycondition() operations. More...

ReturnCode_t	set_qos (const DataReaderQos &qos)
	Sets the DataReaderQos values. More...

ReturnCode_t	get_qos (DataReaderQos &qos)
	Returns the current DataReaderQos settings held in the DataReader dr. More...

ReturnCode_t	set_listener (DataReaderListener *a_listener, StatusMask mask)
	Installs a DataReaderListener on DataReader dr. More...

DataReaderListener *	get_listener ()
	This operation returns the currently installed DataReaderListener. More...

TopicDescription *	get_topicdescription ()
	Returns the TopicDescription associated with DataReader dr. More...

Subscriber *	get_subscriber ()
	Returns the Subscribier that contains DataReader dr.

ReturnCode_t	get_sample_rejected_status (SampleRejectedStatus *status)
	Provides access to the current SampleRejectedStatus of the DataReader. More...

ReturnCode_t	get_liveliness_changed_status (LivelinessChangedStatus *status)
	Provides access to the current LivelinessChangedStatus of the DataReader. More...

ReturnCode_t	get_requested_deadline_missed_status (RequestedDeadlineMissedStatus *status)
	Provides access to the current RequestedDeadlineMissedStatus of the DataReader. More...

ReturnCode_t	get_requested_incompatible_qos_status (RequestedIncompatibleQosStatus *status)
	Provides access to the current RequestedIncompatibleQosStatus of the DataReader. More...

ReturnCode_t	get_subscription_matched_status (SubscriptionMatchedStatus *status)
	Provides access to the current SubscriptionMatchedStatus of the DataReader. More...

ReturnCode_t	get_sample_lost_status (SampleLostStatus *status)
	Provides access to the current SampleLostStatus of the DataReader. More...

ReturnCode_t	wait_for_historical_data (const Duration_t &max_wait)
	This routine blocks until all 'historical' data is received.

ReturnCode_t	get_matched_publications (InstanceHandleSeq *publication_handles)
	This operation retrieves the list of DataWriters currently matched with the DataReader dr. More...

ReturnCode_t	get_matched_publication_data (PublicationBuiltinTopicData *publication_data, const InstanceHandle_t publication_handle)
	This operation returns data that describes a particular matched DataWriter identified by publication_handle. More...

QueryCondition *	create_querycondition (SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states, const char *query_expression, const StringSeq &query_parameters)
	Creates a QueryCondition. More...

ReturnCode_t	read (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation accesses a collection of data values (with associated SampleInfo) within the DataReader. More...

ReturnCode_t	take (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation takes a collection of data values (with associated SampleInfo) from the DataReader. More...

ReturnCode_t	read_w_condition (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, ReadCondition *a_condition)
	This operation accesses a collection of data values (with associated SampleInfo), subject to a filter, within the DataReader. More...

ReturnCode_t	take_w_condition (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, ReadCondition *a_condition)
	This operation takes a collection of data values (with associated SampleInfo), subject to a filter, from the DataReader. More...

ReturnCode_t	read_next_sample (void received_data, SampleInfo sample_info)
	This operation accesses a data value (with associated SampleInfo) within the DataReader. More...

ReturnCode_t	take_next_sample (void received_data, SampleInfo sample_info)
	This operation takes a data value (with associated SampleInfo) from the DataReader. More...

ReturnCode_t	read_instance (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t a_handle, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation accesses a collection of data values (with associated SampleInfo), belonging to a particular instance, within the DataReader. More...

ReturnCode_t	take_instance (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t a_handle, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation takes a collection of data values (with associated SampleInfo), belonging to a particular instance, from the DataReader. More...

ReturnCode_t	read_next_instance (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t previous_handle, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation accesses a collection of data values (with associated SampleInfo), instance by instance, within the DataReader. More...

ReturnCode_t	take_next_instance (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t previous_handle, SampleStateMask sample_states, ViewStateMask view_states, InstanceStateMask instance_states)
	This operation takes a collection of data values (with associated SampleInfo), instance by instance, from the DataReader. More...

ReturnCode_t	read_next_instance_w_condition (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t previous_handle, ReadCondition *a_condition)
	This operation accesses a collection of data values (with associated SampleInfo), instance by instance subject to a filter, within the DataReader. More...

ReturnCode_t	take_next_instance_w_condition (Sequence received_data, SampleInfoSeq sample_infos, long max_samples, InstanceHandle_t previous_handle, ReadCondition *a_condition)
	This operation takes a collection of data values (with associated SampleInfo), instance by instance subject to a filter, from the DataReader. More...

ReturnCode_t	return_loan (Sequence received_data, SampleInfoSeq sample_infos)
	Returns data and sample_info values to a DataReader. More...

ReturnCode_t	get_key_value (void *key_holder, InstanceHandle_t handle)
	This routine will populate the data structure indicated by key_holder with the key infomation identified by handle. More...

InstanceHandle_t	lookup_instance (void *instance_data)
	Returns the handle that identifies the data instance provided in instance_data. More...

ReturnCode_t	get_guid (GUID_t *guid)
	Access the GUID which uniquely identifies this reader.

Detailed Description

The DataReader entity allows the application to subscribe to and read data.

The DataReadre is an abstract 'class' that is extended to support a particular data type required by the application. A DataReader is associated with a single TopicDescription (Topic, MultiTopic, or ContentFilteredTopic).

Member Function Documentation

QueryCondition* DDS::DataReader::create_querycondition	(	SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states,
		const char *	query_expression,
		const StringSeq &	query_parameters
	)

Creates a QueryCondition.

The returned QueryCondition can be used as an argument to read_w_condition() or take_w_condition().

The \b query_expression is an SQL like condition expression, and \b query_parameters
provide optional parameters that are referenced by the \b query_expression.
The syntax of the query expression is similar to the WHERE clause in SQL. For example
"x<4" is a valid query expression. It would test that data member 'x' is less than value '4'.
If the query expression evaluates to TRUE, then the data sample will be available, otherwise
the data sample will be 'filtered' (excluded).

CoreDX %DDS supports the '<b>LIKE</b>' operator (and NOT LIKE) for regular expression string matching.
The pattern string in a LIKE clause can contain '%' to match zero or more characters, '_' to
match a single character, or '[&lt;characters&gt;]' to match a range of characters.

CoreDX %DDS also includes support for the '<b>IN</b>' operator. This provides a very powerful mechanism
for testing that a value appears in a set of values. For example "symbol IN ('ge', 'msft', 'ibm')"
will select all samples that have a symbol value of 'ge', 'msft', or 'ibm'. This could also be
written as a series of equality tests combined with the OR operator; however, the IN operator
is much more efficient. A query that matches on several hundred or even thousands of values
can be implemented very efficiently using the 'IN' operator.

The query_expression can refer to parameters. The syntax for paramters is the percent sign '%'
followed by a number. The number is the index of the paramter in the \b query_paramters sequence.
Parameters are counted starting at zero. So, "%0" refers to the first parameter, and "%4"
refers to the fifth paramter. Using this syntax, the expression "x<%0" would test the value
of 'x' against the first parameter in the sequence.

See also: QueryCondition; DataReader_read_w_condition(); DataReader_take_w_condition()

ReadCondition* DDS::DataReader::create_readcondition	(	SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

Creates a ReadCondition that is associated with this DataReader.

The returned condition can be added to a WaitSet or used in a call to the specialized read() or take() operations. For example see DataReader_read_w_condition().

ReturnCode_t DDS::DataReader::delete_contained_entities ( )

This operation deletes all the ReadCondition and QueryCondition objects previously created by means of the DataReader_create_readcondition() and DataReader_create_querycondition() operations.

After successful execution, the application may delete the Publisher by calling Subscriber_delete_datareader().

If any of the objects cannot be deleted, this routine will return RETCODE_PRECONDITION_NOT_MET.

ReturnCode_t DDS::DataReader::delete_readcondition ( ReadCondition * a_condition )

Destroys a ReadCondition (or QueryCondition).

The provided a_condition must have been previously created via a call to DataReader_create_readcondition() or DataReader_create_querycondition().

The a_condition argument must belong to DataReader dr. Otherwise, the error RETCODE_PRECONDITION_NOT_MET will be returned.

If the DataReader is actively processing the ReadCondition, this routine will return RETCODE_ERROR; in this case, the delete_readcondition() call should be re-tried.

ReturnCode_t DDS::DataReader::enable ( )

virtual

Enables the DataReader.

A DataReader is created either enabled or not based on the SubscriberQos setting entity_factory. When a DataReader is not enabled, only the following sub-set of all DataReader operations are legal:

operations to get and set QoS policies,
get_statuscondition(),
get_status_changes(),

Any other operation may return the NOT_ENABLED error. DataReader_enable() may be called on an already enabled DataReader [it will have no effect].

Reimplemented from DDS::Entity.

ReturnCode_t DDS::DataReader::get_key_value	(	void *	key_holder,
		InstanceHandle_t	handle
	)

This routine will populate the data structure indicated by key_holder with the key infomation identified by handle.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

DataReaderListener* DDS::DataReader::get_listener ( )

This operation returns the currently installed DataReaderListener.

Note: Because the infrastructure makes a copy of the listener provided in DataReader_set_listener(), the returned structure pointer will not match the pointer originally provided. However, the function pointers within the structure will match. Also, the application should not free the data referenced by the returned pointer.

ReturnCode_t DDS::DataReader::get_liveliness_changed_status ( LivelinessChangedStatus * status )

Provides access to the current LivelinessChangedStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

ReturnCode_t DDS::DataReader::get_matched_publication_data	(	PublicationBuiltinTopicData *	publication_data,
		const InstanceHandle_t	publication_handle
	)

This operation returns data that describes a particular matched DataWriter identified by publication_handle.

An appropriate handle can be obtained through a call to DataReader_get_matched_publications().

If publication_handle does not identify a matched DataWriter, this routine will return RETCODE_PRECONDITION_NOT_MET.

ReturnCode_t DDS::DataReader::get_matched_publications ( InstanceHandleSeq * publication_handles )

This operation retrieves the list of DataWriters currently matched with the DataReader dr.

This list will include the handles that identify DataWriters which have matching Topic and compatible QoS with DataReader.

If a DataWriter has been ignored by a call to DomainParticipant_ignore_publication(), then it will not appear in the list.

ReturnCode_t DDS::DataReader::get_qos ( DataReaderQos & qos )

Returns the current DataReaderQos settings held in the DataReader dr.

This routines copies data from the DataReader QoS properties into qos.

Note: The qos structure may contain sequences or strings that are populated with dynamic memory. The caller is responsible for freeing the dynamic memory of these items.
For example, the sequence 'qos->user_data' may have dynamically allocated memory assigned. This can be released by a call to seq_clear(&qos->user_data).

ReturnCode_t DDS::DataReader::get_requested_deadline_missed_status ( RequestedDeadlineMissedStatus * status )

Provides access to the current RequestedDeadlineMissedStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

ReturnCode_t DDS::DataReader::get_requested_incompatible_qos_status ( RequestedIncompatibleQosStatus * status )

Provides access to the current RequestedIncompatibleQosStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

ReturnCode_t DDS::DataReader::get_sample_lost_status ( SampleLostStatus * status )

Provides access to the current SampleLostStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

ReturnCode_t DDS::DataReader::get_sample_rejected_status ( SampleRejectedStatus * status )

Provides access to the current SampleRejectedStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

StatusMask DDS::DataReader::get_status_changes ( )

virtual

This returns the list of triggered communication statuses in the DataReader.

If the DataReader is not enabled, all statuses will be untriggered.

Implements DDS::Entity.

ReturnCode_t DDS::DataReader::get_subscription_matched_status ( SubscriptionMatchedStatus * status )

Provides access to the current SubscriptionMatchedStatus of the DataReader.

As a side-effect, this routine will reset the total_count_change status field to zero.

TopicDescription* DDS::DataReader::get_topicdescription ( )

Returns the TopicDescription associated with DataReader dr.

The returned TopicDescription is really a Topic, ContentFilteredTopic or MultiTopic.

InstanceHandle_t DDS::DataReader::lookup_instance ( void * instance_data )

Returns the handle that identifies the data instance provided in instance_data.

The 'key' field values of the data are associated with a unique handle.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

ReturnCode_t DDS::DataReader::read	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation accesses a collection of data values (with associated SampleInfo) within the DataReader.

This routine, and the related take(), provide the interface for an application to access published data. There are several varieties of read() and take(), to facilitate different access patterns or approaches.

The primary difference between read() and take() is that take() removes all returned data samples from the DataReader while read() does not. Sequential read() calls will return the same data samples each time (if nothing else changes); while sequential take() calls will return data samples for only the first call. Subsequent take() calls will return an empty collection (if no new data arrives).

The specific behavior of read() depends on several things: input paramters, the QoS settings of the DataReader, and the state of recieved data. First, the received_data and sample_infos arguments affect the following:

how many samples are returned, and
whether the returned data should be 'loaned' or copied.

The argument max_samples is used to further limit the number of samples returned.

The sample_states, view_states, and instance_states arguments are used to selectively add data samples to the returned collections. These arguments indicate the desired 'states' for data samples and instances. These state arguments are bit masks; they can be the bit-wise OR of several individual state flags or they may use the special 'ANY' constants (e.g.: ANY_SAMPLE_STATE). Only samples that have a matching state for all three categories are added to the returned collection.

The order of samples in the returned collections is determined by the PRESENTATION and DESTINATION_ORDER QoS policies.

The returned collection is held in recieved_data and samples_infos. These two sequences operate together to represent a sequence of pairs (data, SampleInfo). Each data item in received_data has a corresponding entry in sample_infos that provides associated 'meta-data'. See SampleInfo for a description of this meta-data.

In CoreDX DDS, the returned sequences contain 'loaned' data. This provides zero-copy access to the data, and provides a very efficient data access mechanism. Becuase the data is 'loaned' to the application, the application is required to indicate when it is finished accessing the data. This is accomplished by calling DataReader_return_loan().

The read() operation will set the SampleInfo::sample_state to READ_SAMPLE_STATE.

The read() operation may set the SampleInfo::view_state to NOT_NEW_VIEW_STATE, if a sample of the most recent generation of the instance is read.

If there is no data found, then the read() will return RETCODE_NO_DATA.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

ReturnCode_t DDS::DataReader::read_instance	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	a_handle,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation accesses a collection of data values (with associated SampleInfo), belonging to a particular instance, within the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_read()

ReturnCode_t DDS::DataReader::read_next_instance	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	previous_handle,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation accesses a collection of data values (with associated SampleInfo), instance by instance, within the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_read()

ReturnCode_t DDS::DataReader::read_next_instance_w_condition	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	previous_handle,
		ReadCondition *	a_condition
	)

This operation accesses a collection of data values (with associated SampleInfo), instance by instance subject to a filter, within the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_read()

ReturnCode_t DDS::DataReader::read_next_sample	(	void *	received_data,
		SampleInfo *	sample_info
	)

This operation accesses a data value (with associated SampleInfo) within the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_read()

ReturnCode_t DDS::DataReader::read_w_condition	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		ReadCondition *	a_condition
	)

This operation accesses a collection of data values (with associated SampleInfo), subject to a filter, within the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_read()

ReturnCode_t DDS::DataReader::return_loan	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos
	)

Returns data and sample_info values to a DataReader.

When an application calls DataReader read() or take() operations, these routines may 'loan' data and SampleInfo values to the application. [This is an optimization that avoids extra copies of data.] The appliction must return this 'loaned' data to the DataReader. The return_loan() routine indicates to the DataReader that the application no longer requires access to the data and sample_infos.

A call to return_loan() operation must be called only if previous read() or take() calls 'loaned' data to the application. See DataReader_read() for a discussion of when data is 'loaned'.

If the received_data or sample_infos parameters provided do not identify data obtained from DataReader dr, then the error RETCODE_PRECONDITION_NOT_MET will be returned.

Note

A DataReader cannot be deleted if any 'loans' are outstanding.

ReturnCode_t DDS::DataReader::set_listener	(	DataReaderListener *	a_listener,
		StatusMask	mask
	)

Installs a DataReaderListener on DataReader dr.

Only one listener may be attached to a DataReader at a time. A call to set_listener() will replace any current listener with a_listener.

a_listener can be NULL, which indicates a listener that does nothing.

The infrastructure will make an internal copy of the listener structure so that it need not be persisted by the application.

ReturnCode_t DDS::DataReader::set_qos ( const DataReaderQos & qos )

Sets the DataReaderQos values.

These QoS values affect the behavior of the DataReader.

ReturnCode_t DDS::DataReader::take	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation takes a collection of data values (with associated SampleInfo) from the DataReader.

This routine, and the related read(), provide the interface for an application to access published data. There are several varieties of read() and take(), to facilitate different access patterns or approaches.

The primary difference between read() and take() is that take() removes all returned data samples from the DataReader while read() does not. Sequential read() calls will return the same data samples each time (if nothing else changes); while sequential take() calls will return data samples for only the first call. Subsequent take() calls will return an empty collection (if no new data arrives).

The specific behavior of take() depends on several things: input paramters, the QoS settings of the DataReader, and the state of recieved data. First, the received_data and sample_infos arguments affect the following:

how many samples are returned, and
whether the returned data should be 'loaned' or copied.

The argument max_samples is used to further limit the number of samples returned.

The sample_states, view_states, and instance_states arguments are used to selectively add data samples to the returned collections. These arguments indicate the desired 'states' for data samples and instances. These state arguments are bit masks; they can be the bit-wise OR of several individual state flags or they may use the special 'ANY' constants (e.g.: ANY_SAMPLE_STATE). Only samples that have a matching state for all three categories are added to the returned collection.

The order of samples in the returned collections is determined by the PRESENTATION and DESTINATION_ORDER QoS policies.

The returned collection is held in recieved_data and samples_infos. These two sequences operate together to represent a sequence of pairs (data, SampleInfo). Each data item in received_data has a corresponding entry in sample_infos that provides associated 'meta-data'. See SampleInfo for a description of this meta-data.

In CoreDX DDS, the returned sequences contain 'loaned' data. This provides zero-copy access to the data, and provides a very efficient data access mechanism. Becuase the data is 'loaned' to the application, the application is required to indicate when it is finished accessing the data. This is accomplished by calling DataReader_return_loan().

The take() operation will set the SampleInfo::sample_state to READ_SAMPLE_STATE.

The take() operation may set the SampleInfo::view_state to NOT_NEW_VIEW_STATE, if a sample of the most recent generation of the instance is taken.

If there is no data found, then the take() will return RETCODE_NO_DATA.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

ReturnCode_t DDS::DataReader::take_instance	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	a_handle,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation takes a collection of data values (with associated SampleInfo), belonging to a particular instance, from the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_take()

ReturnCode_t DDS::DataReader::take_next_instance	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	previous_handle,
		SampleStateMask	sample_states,
		ViewStateMask	view_states,
		InstanceStateMask	instance_states
	)

This operation takes a collection of data values (with associated SampleInfo), instance by instance, from the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_take()

ReturnCode_t DDS::DataReader::take_next_instance_w_condition	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		InstanceHandle_t	previous_handle,
		ReadCondition *	a_condition
	)

This operation takes a collection of data values (with associated SampleInfo), instance by instance subject to a filter, from the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_take()

ReturnCode_t DDS::DataReader::take_next_sample	(	void *	received_data,
		SampleInfo *	sample_info
	)

This operation takes a data value (with associated SampleInfo) from the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_take()

ReturnCode_t DDS::DataReader::take_w_condition	(	Sequence *	received_data,
		SampleInfoSeq *	sample_infos,
		long	max_samples,
		ReadCondition *	a_condition
	)

This operation takes a collection of data values (with associated SampleInfo), subject to a filter, from the DataReader.

Note: This routine is data type specific. The generated type specific DataReader includes an implementation of this routine which should be used to support type-safety.

See also: DataReader_take()

Public Member Functions

Detailed Description

Member Function Documentation