DDS::GroupDataQosPolicy Class Reference
[GROUP_DATA]

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

#include <managed_infrastructure.h>

List of all members.

Static Public Member Functions
static System::String^	get_groupdata_qos_policy_name ()
	Stringified human-readable name for DDS::GroupDataQosPolicy.
Public Attributes
ByteSeq^	value
	a sequence of octets

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Detailed Description

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

Entity:

DDS::Publisher, DDS::Subscriber

Properties:

RxO = NO
Changeable = YES

See also:

DDS::DomainParticipant::get_builtin_subscriber

Usage

The additional information is attached to a DDS::Publisher or DDS::Subscriber. This extra data is not used by RTI Data Distribution Service itself. When a remote application discovers the DDS::Publisher or DDS::Subscriber, it can access that information and use it for its own purposes.

Use cases for this QoS policy, as well as the DDS::TopicDataQosPolicy and DDS::UserDataQosPolicy, are often application-to-application identification, authentication, authorization, and encryption purposes. For example, applications can use Group or User Data to send security certificates to each other for RSA-type security.

In combination with DDS::DataReaderListener, DDS::DataWriterListener and operations such as DDS::DomainParticipant::ignore_publication and DDS::DomainParticipant::ignore_subscription, this QoS policy can help an application to define and enforce its own security policies. For example, an application can implement matching policies similar to those of the DDS::PartitionQosPolicy, except the decision can be made based on an application-defined policy.

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

Important: RTI Data Distribution Service stores the data placed in this policy in pre-allocated pools. It is therefore necessary to configure RTI Data Distribution Service with the maximum size of the data that will be stored in policies of this type. This size is configured with DDS::DomainParticipantResourceLimitsQosPolicy::publisher_group_data_max_length and DDS::DomainParticipantResourceLimitsQosPolicy::subscriber_group_data_max_length.

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Member Data Documentation

ByteSeq ^ DDS::GroupDataQosPolicy::value

a sequence of octets

[default] Empty (zero-sized)

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