Module: dds.qos

class dds.qos.DataRepresentationQosPolicy

Describes the data representation used by a topic

class dds.qos.DataTagQosPolicy

A sequence of name-value pair ‘tags’.

class dds.qos.DeadlineQosPolicy

Deadline QoS Policy

Parameters:period – (Duration) deadline duration (default: infinite)
period

dds.core.Duration

class dds.qos.DestinationOrderKind
BY_RECEPTION_TIMESTAMP
BY_SOURCE_TIMESTAMP
class dds.qos.DestinationOrderQosPolicy

DestinationOrder QoS Policy

Parameters:kind – (dds.qos.DestinationOrderKind) ordering
kind

(dds.qos.DestinationOrderKind)

class dds.qos.DiscoveryQosPolicy

Discovery Qos Policy controls the behavior of the Participant’s builtin Entities that manage discovery

Parameters:
  • discovery_kind (integer) – the kind of discovery to use (0 is only value supported)
  • dpd_push_period (Duration) – how often the bootstrap discovery message should be transmitted [keep at default unless you are sure]
  • dpd_lease_duration (Duration) – how long our peer should consider this participant to be alive without hearing from it [keep at default unless you are sure]
  • heartbeat_period (Duration) – periodicity of HB transmission
  • nack_response_delay (Duration) – time before responding to a NACK
  • nack_suppress_delay (Duration) – time to ignore subsequent NACKs [not effective]
  • min_buffer_size (integer) – initial size of outgoing msg buffer [can grow up to max_buffer_size]
  • max_buffer_size (integer) – maximum size of outgoing msg buffer [data samples will fragment if larger]
  • heartbeat_response_delay (Duration) – time before responding to a HB
  • send_initial_nack (bool) – should the reader send an initial nack to all matched writers
  • send_msglen_submsg (bool) – should RTPS messages include a ‘len’ submsg (default: True)
class dds.qos.DurabilityKind
VOLATILE
TRANSIENT_LOCAL
TRANSIENT
PERSISTENT
class dds.qos.DurabilityQosPolicy

Durability QoS Policy

Args: kind: (dds.qos.DurabilityKind)
kind of durability
class dds.qos.DurabilityServiceQosPolicy

DurabilityService QoS Policy

Parameters:
  • service_cleanup_delay (Duration) – set service_cleanup_delay (default: 0)
  • history_kind (HistoryKind) – set history kind (default: KEEP_LAST)
  • history_depth (long) – set history_depth (default: 1)
  • max_samples (long) – set max_samples (default: unlimited)
  • max_instances (long) – set max_instances (default: unlimited)
  • max_samples_per_instance (long) – set max_samples_per_instance (default: unlimited)
class dds.qos.EntityFactoryQosPolicy

EntityFactory QoS Policy

Parameters:autoenable (bool) – AutoEnable each created entity
class dds.qos.EntityNameQosPolicy

EntityName QoS Policy associates a name with a DDS Entity

Parameters:value (string) – set the name [first 32 bytes are used by the core]
class dds.qos.GroupDataQosPolicy

GroupData QoS Policy

Args: value: (bytes)
the value of the GroupData policy
class dds.qos.HistoryQosPolicy

History QoS Policy

Parameters:
  • kind (HistoryKind) – History kind
  • depth (int) – History depth (default: 1)
class dds.qos.LatencyBudgetQosPolicy

LatencyBudget QoS Policy

Parameters:duration (Duration) – duration of latency budget (default: 0)
class dds.qos.LifespanQosPolicy

Lifespan QoS Policy

Parameters:duration (Duration) – duration of lifespan (default: infinite)
class dds.qos.LivelinessQosPolicy

Liveliness QoS Policy

Parameters:
  • kind (LivelinessKind) – Liveliness kind
  • lease_duration (Duration) – Lease duration (default: infinity)
class dds.qos.Locator

Locator represents a DDS Locator

Parameters:
  • kind – (integer) the kind of locator
  • port – (integer) the socket ‘port’ of the locator
  • addr – (integer[]) the values of the address. For example, an IPv4 address would be composed of 4 integers (all with value 0..255).
class dds.qos.LoggingQosPolicy

Logging Qos Policy controls the logging output from the core library

This requires that the python interpreter loads the ‘_log’ version of the CoreDX DDS library.

Argument flags: (integer)
set bits in the ‘flags’ variable to turn on various types of logging
class dds.qos.OwnershipQosPolicy

Ownership QoS Policy

Parameters:kind (OwnershipKind) – Ownership kind
class dds.qos.OwnershipStrengthQosPolicy

Ownership strenth QoS Policy

Parameters:value (int) – value for strength (default: 0)
class dds.qos.ParticipantLocator

ParticipantLocator represents a loctor that specifies one or more DomainParticipants at a certain location

Parameters:
  • id – (integer) the first ‘participant_id’ to target at ‘addr’
  • id_max – (integer) the last ‘participant_id’ to target at ‘addr’
  • locator – (Locator) the location to target
class dds.qos.PartitionQosPolicy

Partition QoS Policy

Parameters:names (list) – list of partition names (strings)
class dds.qos.PeerParticipantQosPolicy

PeerParticipant Qos Policy pre-defines a set of peers

If the ‘strict_match’ parameter is set to True, then the Participant will be limited to matching only with the specified participants.

Parameters:
  • value – ( ParticipantLocator [] ) a set of ParticipantLocator’s to attempt to match with
  • strict_match – (bool) whether matching should be limited to only the listed peers
class dds.qos.PresentationQosPolicy

Presentation QoS Policy

Parameters:
  • access_scope (PresentationAccessScopeKind) – Presentation kind (default: INSTANCE)
  • coherent_access (bool) – Set coherent access (default: False)
  • ordered_access (bool) – Set ordered access (default: False)
class dds.qos.PropertyQosPolicy

Property Qos Policy associates a set of properties (name,value pairs) with the QoS

class dds.qos.RTPSReaderQosPolicy

RTPSReader Qos Policy controls the behavior of the internal RTPS Reader associated with a DataReader

Parameters:
  • heartbeat_response_delay (Duration) – time before responding to a HB
  • accept_batch_msg (bool) – should the reader indicate that it can accept BATCH msgs
  • send_typecode (bool) – should the reader send type information (TypeCode or TypeObject) [can be large]
  • send_initial_nack (bool) – should the reader send an initial nack to all matched writers
  • precache_max_samples (integer) – configure how many samples a reader can hold before making available to the DataReader
  • locators (Locator[]) – override the default locators associated with this RTPS Reader (useful for segregating multicast traffic)
class dds.qos.RTPSWriterQosPolicy

RTPSWriter Qos Policy controls the behavior of the internal RTPS Writer associated with a DataWriter

Parameters:
  • heartbeat_period – (Duration) periodicity of HB transmission
  • nack_response_delay – (Duration) time before responding to a NACK
  • nack_suppress_delay – (Duration) nack_suppress_delay: time to ignore subsequent NACKs [not effective]
  • ack_deadline – (Duration) how long to wait for an ACK
  • min_buffer_size – (integer) initial size of outgoing msg buffer [can grow up to max_buffer_size]
  • max_buffer_size – (integer) maximum size of outgoing msg buffer [data samples will fragment if larger]
  • apply_filters – (bool) should the writer apply content filters discovered from matching peers
  • enable_batch_msg – (bool) should the writer send BATCH rtps messages if deemed useful
  • send_typecode – (bool) should the writer send type information (TypeCode or TypeObject) [can be large]
  • require_acks – (bool) should the writer require matched reliable readers to send positive ACKs
  • reliable_sample_hold_time – (Duration) how long a writer must hold a sample if it hasn’t been ACKd by all matched reliable readers
class dds.qos.ReaderDataLifecycleQosPolicy

ReaderDataLifecycle QoS Policy

Parameters:
  • autopurge_nowriter_samples_delay (Duration) – set autopurge_nowriter_samples (default: infinity)
  • autopurge_disposed_samples_delay (Duration) – set autopurge_nowriter_samples (default: infinity)
class dds.qos.ReliabilityQosPolicy

Reliability QoS Policy

Parameters:
  • kind (ReliabilityKind) – Reliability kind
  • max_blocking_time (Duration) – Maximum blocking time (default: 100 milliseconds)
class dds.qos.ResourceLimitsQosPolicy

Resource limit QoS Policy

Parameters:
  • max_samples (int) – maximum samples (default: -1)
  • max_instances (int) – maximum instances (default: -1)
  • max_samples_per_instance (int) – maximum samples per instance (default: -1)
class dds.qos.RpcQosPolicy

Augment a DataWriter or DataReader with RPC specific information.

class dds.qos.ThreadModelQosPolicy

ThreadModel Qos Policy controls the behavior of the core threading

Parameters:
  • use_threads (bool) – should the core create internal threads to process async events (default: True)
  • create_listener_thread (bool) – if use_threads is True, then this controls whether the core will create an additional thread to invoke user listener callbacks (default: False)
class dds.qos.TimeBasedFilterQosPolicy

Time based filter QoS Policy

Parameters:minimum_separation (Duration) – Value for minimum separation (default: 0)
class dds.qos.TopicDataQosPolicy

TopicData QoS Policy

Parameters:value (string) – value
class dds.qos.TransportPriorityQosPolicy

TransportPriority QoS Policy

Parameters:value (int) – value for transport priority
class dds.qos.TypeConsistencyEnforcementQosPolicy

rules for determining type consistency The Type Consistency Enforcement QoS Policy defines the rules for determining whether the type used to publish a given data stream is consistent with that used to subscribe to it. It applies to DataReaders.

kind

dds.qos.TypeConsistencyKind – allow or disallow type coercion

class dds.qos.TypecodeQosPolicy

Binary representation of type information

value

dds.core.OctetSeq – sequence of bytes representing the TypeCode for the data type

encoding

byte – encoding of the typecode bytes (little endian / big endian)

class dds.qos.UserDataQosPolicy

UserData QoS Policy

Parameters:value (byte[]) – value of the UserData policy
class dds.qos.WriterDataLifecycleQosPolicy

WriterDataLifecycle QoS Policy

Parameters:autodispose_unregistered_instances (bool) – set autodispose_unregistered_instances (default: true)