sub

class cyclonedds.sub.Subscriber(domain_participant, qos=None, listener=None)

Bases: cyclonedds.core.Entity

Parameters

• domain_participant (cyclonedds.domain.DomainParticipant) –

• qos (Optional[cyclonedds.qos.Qos]) –

• listener (Optional[cyclonedds.core.Listener]) –

notify_readers()

class cyclonedds.sub.DataReader(subscriber_or_participant, topic, qos=None, listener=None)

Bases: cyclonedds.core.Entity, Generic[cyclonedds.sub._T]

Subscribe to a topic and read/take the data published to it.

Parameters

• subscriber_or_participant (Union[cyclonedds.sub.Subscriber, cyclonedds.domain.DomainParticipant]) –

• topic (cyclonedds.topic.Topic[cyclonedds.sub._T]) –

• qos (Optional[cyclonedds.qos.Qos]) –

• listener (Optional[cyclonedds.core.Listener]) –

property topic: cyclonedds.topic.Topic[cyclonedds.sub._T]

read(N=1, condition=None, instance_handle=None)

Read a maximum of N samples, non-blocking. Optionally use a read/query-condition to select which samples you are interested in.

Parameters

• N (int) – The maximum number of samples to read.

• condition (cyclonedds.core.ReadCondition, cyclonedds.core.QueryCondition, optional) – Only read samples that satisfy the supplied condition.

• instance_handle (Optional[int]) –

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Return type

List[cyclonedds.sub._T]

take(N=1, condition=None, instance_handle=None)

Take a maximum of N samples, non-blocking. Optionally use a read/query-condition to select which samples you are interested in.

Parameters

• N (int) – The maximum number of samples to read.

• condition (cyclonedds.core.ReadCondition, cyclonedds.core.QueryCondition, optional) – Only take samples that satisfy the supplied condition.

• instance_handle (Optional[int]) –

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Return type

List[cyclonedds.sub._T]

read_next()

Shortcut method to read exactly one sample or return None.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Return type

Optional[cyclonedds.sub._T]

take_next()

Shortcut method to take exactly one sample or return None.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Return type

Optional[cyclonedds.sub._T]

read_iter(condition=None, timeout=None)

Shortcut method to iterate reading samples. Iteration will stop once the timeout you supply expires. Every time a sample is received the timeout is reset.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Parameters

timeout (Optional[int]) –

Return type

Generator[cyclonedds.sub._T, None, None]

read_one(condition=None, timeout=None)

Shortcut method to block and take exactly one sample or raise a timeout

Parameters

timeout (Optional[int]) –

Return type

cyclonedds.sub._T

take_iter(condition=None, timeout=None)

Shortcut method to iterate taking samples. Iteration will stop once the timeout you supply expires. Every time a sample is received the timeout is reset.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Parameters

timeout (Optional[int]) –

Return type

Generator[cyclonedds.sub._T, None, None]

take_one(condition=None, timeout=None)

Shortcut method to block and take exactly one sample or raise a timeout

Parameters

timeout (Optional[int]) –

Return type

cyclonedds.sub._T

async read_aiter(condition=None, timeout=None)

Shortcut method to asycn iterate reading samples. Iteration will stop once the timeout you supply expires. Every time a sample is received the timeout is reset.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Parameters

timeout (Optional[int]) –

Return type

AsyncGenerator[cyclonedds.sub._T, None]

async take_aiter(condition=None, timeout=None)

Shortcut method to asycn iterate taking samples. Iteration will stop once the timeout you supply expires. Every time a sample is received the timeout is reset.

Raises

DDSException – If any error code is returned by the DDS API it is converted into an exception.

Parameters

timeout (Optional[int]) –

Return type

AsyncGenerator[cyclonedds.sub._T, None]

wait_for_historical_data(timeout)

Parameters

timeout (int) –

Return type

bool

lookup_instance(sample)

Parameters

sample (cyclonedds.sub._T) –

Return type

Optional[int]