dds module

DDS Python DCPS API class

class dds.Condition

Bases: object

Abstract condition class

triggered()
class dds.DDSDestinationOrderKind

Bases: enum.Enum

BY_RECEPTION_TIMESTAMP = 0
BY_SOURCE_TIMESTAMP = 1
class dds.DDSDurabilityKind

Bases: enum.Enum

PERSISTENT = 3
TRANSIENT = 2
TRANSIENT_LOCAL = 1
VOLATILE = 0
class dds.DDSDuration

Bases: dds.DDSTime

DDS Duration

Parameters:
  • sec (long) – seconds (default: 0)
  • nanosec (long) – nanoseconds (default: 0)
infinity

Return DDSDuration for infinity

exception dds.DDSException

Bases: Exception

DDS exception

__init__()
class dds.DDSHistoryKind

Bases: enum.Enum

KEEP_ALL = 1
KEEP_LAST = 0
class dds.DDSLivelinessKind

Bases: enum.Enum

AUTOMATIC = 0
MANUAL_BY_PARTICIPANT = 1
MANUAL_BY_TOPIC = 2
class dds.DDSMaskUtil

Bases: object

Mask utility. Some commonly used mask combination See DDSStateKind for list of available status

all_samples

[DDSStateKind.ANY_STATE]

Return type:list
Returns:list of DDSStateKind enumeration literals
new_instance_samples

[DDSStateKind.NOT_READ_SAMPLE_STATE, DDSStateKind.ALIVE_INSTANCE_STATE, DDSStateKind.NEW_VIEW_STATE]

Return type:list
Returns:list of DDSStateKind enumeration literals
new_samples

[DDSStateKind.NOT_READ_SAMPLE_STATE, DDSStateKind.ALIVE_INSTANCE_STATE, DDSStateKind.ANY_VIEW_STATE]

Return type:list
Returns:list of DDSStateKind enumeration literals
not_alive_instance_samples

[DDSStateKind.ANY_SAMPLE_STATE, DDSStateKind.ANY_VIEW_STATE, DDSStateKind.NOT_ALIVE_NO_WRITERS_INSTANCE_STATE, DDSStateKind.NOT_ALIVE_DISPOSED_INSTANCE_STATE]

Return type:list
Returns:list of DDSStateKind enumeration literals
read_samples

[DDSStateKind.READ_SAMPLE_STATE, DDSStateKind.ALIVE_INSTANCE_STATE, DDSStateKind.ANY_VIEW_STATE]

Return type:list
Returns:list of DDSStateKind enumeration literals
class dds.DDSOwnershipKind

Bases: enum.Enum

EXCLUSIVE = 1
SHARED = 0
class dds.DDSPresentationAccessScopeKind

Bases: enum.Enum

GROUP = 2
INSTANCE = 0
TOPIC = 1
class dds.DDSReliabilityKind

Bases: enum.Enum

BEST_EFFORT = 0
RELIABLE = 1
class dds.DDSStateKind

Bases: enum.Enum

ALIVE_INSTANCE_STATE = 16
ANY_INSTANCE_STATE = 112
ANY_SAMPLE_STATE = 3
ANY_STATE = 127
ANY_VIEW_STATE = 12
NEW_VIEW_STATE = 4
NOT_ALIVE_DISPOSED_INSTANCE_STATE = 32
NOT_ALIVE_NO_WRITERS_INSTANCE_STATE = 64
NOT_NEW_VIEW_STATE = 8
NOT_READ_SAMPLE_STATE = 2
READ_SAMPLE_STATE = 1
class dds.DDSStatusKind

Bases: enum.Enum

DATA_AVAILABLE = 1024
DATA_ON_READERS = 512
INCONSISTENT_TOPIC = 1
LIVELINESS_CHANGED = 4096
LIVELINESS_LOST = 2048
OFFERED_DEADLINE_MISSED = 2
OFFERED_INCOMPATIBLE_QOS = 32
PUBLICATION_MATCHED = 8192
REQUESTED_DEADLINE_MISSED = 4
REQUESTED_INCOMPATIBLE_QOS = 64
SAMPLE_LOST = 128
SAMPLE_REJECTED = 256
SUBSCRIPTION_MATCHED = 16384
class dds.DDSTime

Bases: object

DDS Time

Parameters:
  • sec (long) – seconds (default: 1)
  • nanosec (long) – nanoseconds (default: 0)
__init__()
class dds.DataReader

Bases: dds.Entity

DataReader class

read(n=1, masks=DDSMaskUtil.all_samples())

Read samples

Parameters:
  • n (int) – number of samples to read
  • masks (list) – list of DDS statuses
Return type:

list
Returns:

list of sample data and sample info tuple
take(n=1, masks=DDSMaskUtil.all_samples())

Take samples

Parameters:
  • n (int) – number of samples to take
  • masks (list) – list of DDS statuses
Return type:

list
Returns:

list of sample data and sample info tuple
wait_for_historical_data(timeout = None)

Wait for data reader to receive historical data, up to timeout duration

Parameters:timeout (DDSDuration) – timeout in seconds(default: infinity)
Return type:boolean
Returns:False if timeout exipred; True otherwise
class dds.DataWriter

Bases: dds.Entity

DataWriter class

dispose_instance(data)

Dispose instance

Parameters:data (object) – Topic data class instance
dispose_instance_ts(data, ts)

Dispose instance with timestamp

Parameters:
  • data (object) – Topic data class instance
  • ts (long) – timestamp
write(data)

Write data

Parameters:data (object) – Topic data class instance
class dds.DeadlineQosPolicy

Bases: dds.QosPolicy

Deadline QoS Policy

Parameters:deadline (DDSDuration) – Value for deadline (default: infinity)
__init__()
deadline
class dds.DestinationOrderQosPolicy

Bases: dds.QosPolicy

Destination order QoS Policy

Parameters:kind (DDSDestinationOrderKind) – Destination order kind
__init__()
class dds.DomainParticipant

Bases: dds.Entity

Domain participant class

Parameters:
  • qos (Qos) – Participant QoS. Default: None
  • listener (Listener) – Participant listener Default: None
create_datareader(Topic topic, Qos qos = None, listener = None)

Create a publisher

Parameters:
  • topic (Topic) – Topic
  • qos (QoS) – QoS
  • listener (Listener) – Listener
Return type:

DataReader
create_datawriter(Topic topic, Qos qos = None, listener = None)

Create a publisher

Parameters:
  • topic (Topic) – Topic
  • qos (QoS) – QoS
  • listener (Listener) – Listener
Return type:

DataWriter
create_publisher(Qos qos = None, listener = None)

Create a publisher

Parameters:
  • qos (QoS) – QoS
  • listener (Listener) – Listener
Return type:

Publisher
create_subscriber(Qos qos = None, listener = None)

Create a subscriber

Parameters:
  • qos (QoS) – QoS
  • listener (Listener) – Listener
Return type:

Subscriber
class dds.DurabilityQosPolicy

Bases: dds.QosPolicy

Durability QoS Policy

Parameters:k (DDSDurabilityKind) – Durability kind
__init__(k=DDSDurabilityKind.VOLATILE)
class dds.DurabilityServiceQosPolicy

Bases: dds.QosPolicy

Durability service QoS Policy

Parameters:
  • service_cleanup_delay (DDSDuration) – set service_cleanup_delay (default: 0)
  • history_kind (DDSHistoryKind) – 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)
__init__()
history_depth
history_kind
max_instances
max_samples
max_samples_per_instance
service_cleanup_delay
class dds.Entity

Bases: object

Abstract base entity class

get_statuscondition()
listener

Listener

parent

Parent entity

class dds.GroupdataQosPolicy

Bases: dds.UserdataQosPolicy

Group data QoS Policy

Parameters:value (string) – value
__init__()
class dds.GuardCondition

Bases: dds.Condition

Guard condition

reset()

Reset guard condition

trigger()

Trigger guard condition

class dds.HistoryQosPolicy

Bases: dds.QosPolicy

History QoS Policy

Parameters:
  • k (DDSHistoryKind) – History kind
  • depth (int) – History depth (default: 1)
__init__(kind=DDSHistoryKind.KEEP_LAST, depth=1)
depth
class dds.LatencyBudgetQosPolicy

Bases: dds.QosPolicy

Latency budget QoS Policy

Parameters:duration (DDSDuration) – Value for duration (default: 0)
__init__()
duration
class dds.LifespanQosPolicy

Bases: dds.QosPolicy

Lifespan QoS Policy

Parameters:lifespan (DDSDuration) – Value for lifespan (default: infinity)
__init__()
lifespan
class dds.Listener

Bases: object

Abstract Listener class. Beta: only on_data_available is implemented.

__init__()
on_data_available(entity)
on_data_readers(entity)
on_inconsistent_topic(entity, status)
on_liveliness_changed(entity, status)
on_liveliness_lost(entity, status)
on_offered_deadline_missed(entity, status)
on_offered_incompatible_qos(entity, status)
on_publication_matched(entity, status)
on_requested_deadline_missed(entity, status)
on_requested_incompatible_qos(entity, status)
on_sample_lost(entity, status)
on_sample_rejected(entity, status)
on_subscription_matched(entity, status)
class dds.LivelinessQosPolicy

Bases: dds.QosPolicy

Liveliness QoS Policy

Parameters:
__init__()
lease_duration
class dds.OwnershipQosPolicy

Bases: dds.QosPolicy

Ownership QoS Policy

Parameters:kind (DDSOwnershipKind) – Ownership kind
__init__()
class dds.OwnershipStrengthQosPolicy

Bases: dds.QosPolicy

Ownership strenth QoS Policy

Parameters:value (int) – value for strength (default: 0)
__init__()
value
class dds.PartitionQosPolicy

Bases: dds.QosPolicy

Partition QoS Policy

Parameters:ps (list) – list of partition names
__init__()
ps
class dds.PresentationQosPolicy

Bases: dds.QosPolicy

Presentation QoS Policy

Parameters:
  • kind (DDSPresentationAccessScopeKind) – Presentation kind (default: INSTANCE)
  • coherent_access (bool) – Set coherent access (default: False)
  • ordered_access (bool) – Set ordered access (default: False)
__init__(kind=DDSHistoryKind.KEEP_LAST, depth=1)
coherent_access
ordered_access
class dds.Publisher

Bases: dds.Entity

Publisher class

create_datawriter(Topic topic, Qos qos = None, listener = None)

Create a data writer :type topic: Topic :param topic: Topic

Parameters:
Return type:

DataWriter
class dds.Qos

Bases: object

QoS class

Parameters:policies (list) – list of QoS policies
set_policies(policies)

Set policies :type policies: list :param policies: list of QoS policies

class dds.QosPolicy

Bases: object

Abstract QoS policy class. Users should not instantiate this class.

__init__(i)
id

An internal QoS Policy id

kind

QoS Policy kind

class dds.QosProfile

Bases: object

QoS Provider class

Parameters:
  • uri (string) – uri to xml file
  • profile (string) – profile name
get_participant_qos()

Create participant QoS

Return type:Qos
get_publisher_qos()

Create publisher QoS

Return type:Qos
get_reader_qos()

Create reader QoS

Return type:Qos
get_subscriber_qos()

Create subscriber QoS

Return type:Qos
get_topic_qos()

Create topic QoS

Return type:Qos
get_writer_qos()

Create writer QoS

Return type:Qos
class dds.QueryCondition

Bases: dds.Condition

Query condition

Parameters:
  • reader (DataReader) – Source DataReader
  • masks (list) – list of masks (default: DDSMaskUtil.all_samples()
  • expression (string) – Expression
  • parameters (list) – list of parameters in string
class dds.ReadCondition

Bases: dds.Condition

Read condition

Parameters:
  • reader (DataReader) – Source DataReader
  • masks (list) – list of masks (default: DDSMaskUtil.all_samples()
class dds.ReaderDataLifecycleQosPolicy

Bases: dds.QosPolicy

Reader data lifecycle QoS Policy

Parameters:
  • autopurge_nowriter_samples (DDSDuration) – set autopurge_nowriter_samples (default: infinity)
  • autopurge_disposed_samples_delay (DDSDuration) – set autopurge_nowriter_samples (default: infinity)
__init__()
autopurge_disposed_samples_delay
autopurge_nowriter_samples
class dds.ReliabilityQosPolicy

Bases: dds.QosPolicy

Reliability QoS Policy

Parameters:
__init__()
max_blocking_time
class dds.ResourceLimitsQosPolicy

Bases: dds.QosPolicy

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)
__init__()
max_instances
max_samples
max_samples_per_instance
class dds.SampleInfo

Bases: object

Base sample info class

__init__()
class dds.StatusCondition

Bases: dds.Condition

Status condition

Parameters:entity (Entity) – Source entity
enable_status()
entity
get_enabled_status()
class dds.Subscriber

Bases: dds.Entity

Subscriber class

create_datareader(Topic topic, Qos qos = None, listener = None)

Create a data reader :type topic: Topic :param topic: Topic

Parameters:
Return type:

DataReader
class dds.TimeBasedFilterQosPolicy

Bases: dds.QosPolicy

Time based filter QoS Policy

Parameters:minimum_separation (DDSDuration) – Value for minimum separation (default: 0)
__init__()
minimum_separation
class dds.Topic

Bases: dds.Entity

Topic class

Parameters:
  • dp (DomainParticipant) – Domain participant
  • name (string) – Topic name
  • qos (Qos) – Topic QoS (default: None)
  • listener (Listener) – Topic listener (default: None)
class dds.TopicdataQosPolicy

Bases: dds.UserdataQosPolicy

Topic data QoS Policy

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

Bases: dds.QosPolicy

Transport priority QoS Policy

Parameters:value (int) – value for transport priority
__init__()
value
class dds.TypeSupport

Bases: object

It is used to generate a dds_topic_descriptor from the provided typename, keys and XML type specification. The size attribute is need to allocate memory when the topic data is deserialized. For the serialization and deserialization the struct module is used

__init__

Initialize self. See help(type(self)) for accurate signature.

deserialize(b)

Deserialize data

handle

C handle

serialize(o)

Serialize data

size

Data size

class dds.UserdataQosPolicy

Bases: dds.QosPolicy

Userdata QoS Policy

Parameters:value (string) – value
__init__()
value
class dds.WaitSet

Bases: object

WaitSet class

attach(Condition cond)

Attach condition :type cond: Condition :param cond: condition to attach

detach(Condition cond)

Detach condition

Parameters:cond (Condition) – condition to detach
get_conditions()

Return conditions

wait(timeout = DDSDuration.infinity())

Wait for any of the conditions attached to the waitset to be triggered

Parameters:timeout (DDSDuration) – timeout in seconds(default: infinity)
Return type:list
Returns:list of Condition objects that were triggered. list is empty if timeout expired
class dds.WriterDataLifecycleQosPolicy

Bases: dds.QosPolicy

Writer data lifecycle QoS Policy

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