This QoS policy contains a list of representation identifiers and compression settings used by com.rti.dds.publication.DataWriter and com.rti.dds.subscription.DataReader entities to negotiate which data representation and compression settings to use. More...
Public Attributes | |
| final ShortSeq | value = new ShortSeq() |
| Sequence of representation identifiers. More... | |
| CompressionSettings_t | compression_settings = new CompressionSettings_t() |
| <<extension>> Structure that contains the compression settings. More... | |
 Public Attributes inherited from QosPolicy | |
| final QosPolicyId_t | id |
| The ID of this QoS policy. More... | |
| final String | policy_name |
| The name of this QoS policy. More... | |
Static Public Attributes | |
| static final short | XCDR_DATA_REPRESENTATION = 0 |
| Corresponds to the Extended Common Data Representation encoding version 1. More... | |
| static final short | XML_DATA_REPRESENTATION = 1 |
| Corresponds to the XML Data Representation (unsupported). More... | |
| static final short | XCDR2_DATA_REPRESENTATION = 2 |
| Corresponds to the Extended Common Data Representation encoding version 2. More... | |
| static final short | AUTO_DATA_REPRESENTATION = -1 |
| Representation is automatically chosen based on the type. More... | |
Detailed Description
This QoS policy contains a list of representation identifiers and compression settings used by com.rti.dds.publication.DataWriter and com.rti.dds.subscription.DataReader entities to negotiate which data representation and compression settings to use.
- Entity:
- com.rti.dds.topic.Topic, com.rti.dds.subscription.DataReader, com.rti.dds.publication.DataWriter
- Status:
- com.rti.dds.infrastructure.StatusKind.StatusKind.OFFERED_INCOMPATIBLE_QOS_STATUS, com.rti.dds.infrastructure.StatusKind.StatusKind.REQUESTED_INCOMPATIBLE_QOS_STATUS
- Properties:
- RxO = YES
Changeable = UNTIL ENABLE
- See also
- DATA_REPRESENTATION
This policy has request-offer semantics for both representation and compression. For representation, a com.rti.dds.publication.DataWriter may only offer a single representation. Attempting to put multiple representations in a com.rti.dds.publication.DataWriter will result in com.rti.dds.infrastructure.RETCODE_INCONSISTENT_POLICY. A com.rti.dds.publication.DataWriter will use its offered policy to communicate with its matched com.rti.dds.subscription.DataReader entities. A com.rti.dds.subscription.DataReader requests one or more representations. If a com.rti.dds.publication.DataWriter offers a representation that is contained within the sequence of the com.rti.dds.subscription.DataReader, the offer satisfies the request and the policies are compatible. Otherwise, they are incompatible.
When representations are specified in the com.rti.dds.topic.TopicQos, com.rti.dds.publication.Publisher.copy_from_topic_qos copies the first element of the sequence, and com.rti.dds.subscription.Subscriber.copy_from_topic_qos copies the whole sequence.
For Compression, only the com.rti.dds.infrastructure.CompressionSettings_t.compression_ids is propagated and a com.rti.dds.publication.DataWriter may only offer a single compression id. Attempting to put multiple compression_ids in a com.rti.dds.publication.DataWriter will result in com.rti.dds.infrastructure.RETCODE_INCONSISTENT_POLICY.
A com.rti.dds.publication.DataWriter will use its offered compression algorithm to compress data that it sends to its matched com.rti.dds.subscription.DataReader entities. A com.rti.dds.subscription.DataReader requests zero or more compression algorithms. If a com.rti.dds.publication.DataWriter offers a representation that is contained within the algorithms requested by the com.rti.dds.subscription.DataReader, the offer satisfies the request and the policies are compatible. Otherwise, they are incompatible.
When compression IDs are specified in the com.rti.dds.topic.TopicQos, com.rti.dds.publication.Publisher.copy_from_topic_qos copies a single compression ID (see com.rti.dds.infrastructure.CompressionSettings_t.compression_ids), and com.rti.dds.subscription.Subscriber.copy_from_topic_qos copies all of the compression_ids.
Member Data Documentation
◆ value
Sequence of representation identifiers.
[default] For com.rti.dds.topic.Topic, com.rti.dds.publication.DataWriter, and com.rti.dds.subscription.DataReader, a list with one element: com.rti.dds.infrastructure.DataRepresentationQosPolicy.AUTO_DATA_REPRESENTATION.
- Note
- An empty sequence is equivalent to a list with one element: com.rti.dds.infrastructure.DataRepresentationQosPolicy.XCDR_DATA_REPRESENTATION.
◆ compression_settings
| CompressionSettings_t compression_settings = new CompressionSettings_t() |
<<extension>> Structure that contains the compression settings.
compression_ids:
[default] The value depends on the entity
com.rti.dds.publication.DataWriter and com.rti.dds.topic.Topic are set to com.rti.dds.infrastructure.CompressionIdMaskBits.MASK_NONE
com.rti.dds.subscription.DataReader com.rti.dds.infrastructure.CompressionIdMaskBits.MASK_ALL
writer_compression_level:
[default] The value depends on the entity
com.rti.dds.publication.DataWriter and com.rti.dds.topic.Topic are set to com.rti.dds.infrastructure.COMPRESSION_LEVEL_DEFAULT
com.rti.dds.subscription.DataReader NOT SUPPORTED
writer_compression_threshold:
[default] The value depends on the entity
com.rti.dds.publication.DataWriter and com.rti.dds.topic.Topic are set to com.rti.dds.infrastructure.COMPRESSION_THRESHOLD_DEFAULT
com.rti.dds.subscription.DataReader NOT SUPPORTED