DDS_TopicDataQosPolicy Struct Reference

Attaches a buffer of opaque data that is distributed by means of Built-in Topics during discovery. More...

Data Fields
struct DDS_OctetSeq	value
	a sequence of octets

Detailed Description

Attaches a buffer of opaque data that is distributed by means of Built-in Topics during discovery.

Entity:

DDS_Topic

Properties:

RxO = NO
Changeable = YES

See Also

DDS_DomainParticipant_get_builtin_subscriber

Usage

The purpose of this QoS is to allow the application to attach additional information to the created DDS_Topic objects, so that when a remote application discovers their existence, it can access that information and use it for its own purposes. This extra data is not used by RTI Connext.

One possible use of this QoS is to attach security credentials or some other information that can be used by the remote application to authenticate the source.

In combination with DDS_DataReaderListener, DDS_DataWriterListener, or operations such as DDS_DomainParticipant_ignore_topic, this QoS policy can assist an application in defining and enforcing its own security policies.

The use of this QoS is not limited to security; it offers a simple, yet flexible extensibility mechanism.

Important: RTI Connext stores the data placed in this policy in pre-allocated pools. It is therefore necessary to configure RTI Connext with the maximum size of the data that will be stored in policies of this type. This size is configured with DDS_DomainParticipantResourceLimitsQosPolicy::topic_data_max_length.

Field Documentation

struct DDS_OctetSeq DDS_TopicDataQosPolicy::value

a sequence of octets

[default] empty (zero-length)

[range] Octet sequence of length [0,max_length]