Defines the rules for determining whether the type used to publish a given topic is consistent with that used to subscribe to it. More...

Inheritance diagram for TypeConsistencyEnforcementQosPolicy:

Public Attributes
TypeConsistencyKind	kind
	Type consistency kind.

boolean	ignore_sequence_bounds
	Controls whether sequence bounds are taken into consideration for type assignability.

boolean	ignore_string_bounds
	Controls whether string bounds are taken into consideration for type assignability.

boolean	ignore_member_names
	Controls whether member names are taken into consideration for type assignability.

boolean	prevent_type_widening
	Controls whether type widening is allowed.

boolean	force_type_validation
	Controls whether type information must be available in order to complete matching between a com.rti.dds.publication.DataWriter and a com.rti.dds.subscription.DataReader.

boolean	ignore_enum_literal_names
	Controls whether enumeration constant names are taken into consideration for type assignability.

Public Attributes inherited from QosPolicy
final QosPolicyId_t	id
	The ID of this QoS policy.

final String	policy_name
	The name of this QoS policy.

Additional Inherited Members
Public Member Functions inherited from Struct
abstract boolean	equals (Object obj)

abstract int	hashCode ()

String	toString ()

Protected Member Functions inherited from Struct
	Struct ()

abstract void	pull_from_nativeI (long native_status)

abstract void	push_to_nativeI (long native_status)

Detailed Description

Defines the rules for determining whether the type used to publish a given topic is consistent with that used to subscribe to it.

This policy defines a type consistency kind, which allows applications to select from among a set of predetermined behaviors. The following consistency kinds are specified: com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.DISALLOW_TYPE_COERCION, com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.ALLOW_TYPE_COERCION and com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.AUTO_TYPE_COERCION.

The type-consistency-enforcement rules consist of two steps:

Step 1. If both the DataWriter and DataReader specify a TypeObject, it is considered first. If the DataReader allows type coercion, then its type must be assignable from the DataWriter's type, taking into account the values of prevent_type_widening, ignore_sequence_bounds, ignore_string_bounds, ignore_member_names, and ignore_enum_literal_names. If the DataReader does not allow type coercion, then its type must be equivalent to the type of the DataWriter.

Step 2. If either the DataWriter or the DataReader does not provide a TypeObject definition, then the registered type names are examined. The DataReader's and DataWriter's registered type names must match exactly, as was true in RTI Connext releases prior to 5.0.0.

If either Step 1 or Step 2 fails, the Topics associated with the DataReader and DataWriter are considered to be inconsistent and the com.rti.dds.topic.InconsistentTopicStatus is updated.

The default enforcement kind is com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.AUTO_TYPE_COERCION. This default kind translates to com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.ALLOW_TYPE_COERCION except in the following cases:

When a Zero Copy DataReader is used, the kind is translated to com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.DISALLOW_TYPE_COERCION.

When the middleware is introspecting the built-in topic data declaration of a remote DataReader in order to determine whether it can match with a local DataWriter, if it observes that no TypeConsistencyEnforcementQosPolicy value is provided (as would be the case when communicating with a Service implementation not in conformance with this specification), it assumes a kind of com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.DISALLOW_TYPE_COERCION.

For additional information on type consistency enforcement refer to the Addendum for Extensible Types and the OMG Extensible and Dynamic Topic Types for DDS Specification.

Entity:: com.rti.dds.subscription.DataReader

Properties:: RxO = N/A
Changeable = UNTIL ENABLE

Member Data Documentation

TypeConsistencyKind kind

Type consistency kind.

[default] com.rti.dds.infrastructure.TypeConsistencyKind.TypeConsistencyKind.AUTO_TYPE_COERCION

boolean ignore_sequence_bounds

Controls whether sequence bounds are taken into consideration for type assignability.

If the option is set to com.rti.dds.infrastructure.true, then sequence bounds (maximum lengths) are not considered as part of the type assignability. This means that a T2 sequence type with maximum length L2 would be assignable to a T1 sequence type with maximum length L1, even if L2 is greater than L1. If the option is set to com.rti.dds.infrastructure.false, then sequence bounds are taken into consideration for type assignability, and in order for T1 to be assignable from T2, it is required that L1 >= L2.