Struct rustdds::dds::with_key::DataReader
source · pub struct DataReader<D: Keyed, DA: DeserializerAdapter<D> = CDRDeserializerAdapter<D>>where
<D as Keyed>::K: Key,{ /* private fields */ }
Expand description
DDS DataReader for with_key topics.
Examples
use serde::{Serialize, Deserialize};
use rustdds::*;
use rustdds::with_key::DataReader;
use rustdds::serialization::CDRDeserializerAdapter;
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
#[derive(Serialize, Deserialize)]
struct SomeType { a: i32 }
impl Keyed for SomeType {
type K = i32;
fn key(&self) -> Self::K {
self.a
}
}
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None);
Note: Many DataReader methods require mutable access to self
, because
they need to mutate the datasample cache, which is an essential content of
this struct.
Implementations§
source§impl<D, DA> DataReader<D, DA>where
D: Keyed + 'static,
<D as Keyed>::K: Key,
DA: DeserializerAdapter<D>,
impl<D, DA> DataReader<D, DA>where D: Keyed + 'static, <D as Keyed>::K: Key, DA: DeserializerAdapter<D>,
sourcepub fn read(
&mut self,
max_samples: usize,
read_condition: ReadCondition
) -> ReadResult<Vec<DataSample<&D>>>
pub fn read( &mut self, max_samples: usize, read_condition: ReadCondition ) -> ReadResult<Vec<DataSample<&D>>>
Reads amount of samples found with max_samples
and read_condition
parameters.
Arguments
max_samples
- Limits maximum amount of samples readread_condition
- Limits results by condition
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
if let Ok(datas) = data_reader.read(10, ReadCondition::not_read()) {
for data in datas.iter() {
// do something
}
}
sourcepub fn take(
&mut self,
max_samples: usize,
read_condition: ReadCondition
) -> ReadResult<Vec<DataSample<D>>>
pub fn take( &mut self, max_samples: usize, read_condition: ReadCondition ) -> ReadResult<Vec<DataSample<D>>>
Takes amount of sample found with max_samples
and read_condition
parameters.
Arguments
max_samples
- Limits maximum amount of samples readread_condition
- Limits results by condition
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
if let Ok(datas) = data_reader.take(10, ReadCondition::not_read()) {
for data in datas.iter() {
// do something
}
}
sourcepub fn read_next_sample(&mut self) -> ReadResult<Option<DataSample<&D>>>
pub fn read_next_sample(&mut self) -> ReadResult<Option<DataSample<&D>>>
Reads next unread sample
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
while let Ok(Some(data)) = data_reader.read_next_sample() {
// do something
}
sourcepub fn take_next_sample(&mut self) -> ReadResult<Option<DataSample<D>>>
pub fn take_next_sample(&mut self) -> ReadResult<Option<DataSample<D>>>
Takes next unread sample
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
while let Ok(Some(data)) = data_reader.take_next_sample() {
// do something
}
sourcepub fn iterator(&mut self) -> ReadResult<impl Iterator<Item = Sample<&D, D::K>>>
pub fn iterator(&mut self) -> ReadResult<impl Iterator<Item = Sample<&D, D::K>>>
Produces an iterator over the currently available NOT_READ samples.
Yields only payload data, not SampleInfo metadata
This is not called iter()
because it takes a mutable reference to self.
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
for data in data_reader.iterator() {
// do something
}
sourcepub fn conditional_iterator(
&mut self,
read_condition: ReadCondition
) -> ReadResult<impl Iterator<Item = Sample<&D, D::K>>>
pub fn conditional_iterator( &mut self, read_condition: ReadCondition ) -> ReadResult<impl Iterator<Item = Sample<&D, D::K>>>
Produces an iterator over the samples filtered by a given condition. Yields only payload data, not SampleInfo metadata
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
for data in data_reader.conditional_iterator(ReadCondition::any()) {
// do something
}
sourcepub fn into_iterator(
&mut self
) -> ReadResult<impl Iterator<Item = Sample<D, D::K>>>
pub fn into_iterator( &mut self ) -> ReadResult<impl Iterator<Item = Sample<D, D::K>>>
Produces an iterator over the currently available NOT_READ samples.
Yields only payload data, not SampleInfo metadata
Removes samples from DataReader
.
Note! If the iterator is only partially consumed, all the
samples it could have provided are still removed from the Datareader
.
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
for data in data_reader.into_iterator() {
// do something
}
sourcepub fn into_conditional_iterator(
&mut self,
read_condition: ReadCondition
) -> ReadResult<impl Iterator<Item = Sample<D, D::K>>>
pub fn into_conditional_iterator( &mut self, read_condition: ReadCondition ) -> ReadResult<impl Iterator<Item = Sample<D, D::K>>>
Produces an iterator over the samples filtered by the given condition.
Yields only payload data, not SampleInfo metadata
Note! If the iterator is only partially consumed, all the
samples it could have provided are still removed from the Datareader
.
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
for data in data_reader.into_conditional_iterator(ReadCondition::not_read()) {
// do something
}
sourcepub fn read_instance(
&mut self,
max_samples: usize,
read_condition: ReadCondition,
instance_key: Option<<D as Keyed>::K>,
this_or_next: SelectByKey
) -> ReadResult<Vec<DataSample<&D>>>
pub fn read_instance( &mut self, max_samples: usize, read_condition: ReadCondition, instance_key: Option<<D as Keyed>::K>, this_or_next: SelectByKey ) -> ReadResult<Vec<DataSample<&D>>>
Works similarly to read(), but will return only samples from a specific instance. The instance is specified by an optional key. In case the key is not specified, the smallest (in key order) instance is selected. If a key is specified, then the parameter this_or_next specifies whether to access the instance with specified key or the following one, in key order.
This should cover DDS DataReader methods read_instance, read_next_instance, read_next_instance_w_condition.
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
if let Ok(datas) = data_reader.read_instance(10, ReadCondition::any(), Some(3), SelectByKey::This) {
for data in datas.iter() {
// do something
}
}
sourcepub fn take_instance(
&mut self,
max_samples: usize,
read_condition: ReadCondition,
instance_key: Option<<D as Keyed>::K>,
this_or_next: SelectByKey
) -> ReadResult<Vec<DataSample<D>>>
pub fn take_instance( &mut self, max_samples: usize, read_condition: ReadCondition, instance_key: Option<<D as Keyed>::K>, this_or_next: SelectByKey ) -> ReadResult<Vec<DataSample<D>>>
Similar to read_instance, but will return owned datasamples This should cover DDS DataReader methods take_instance, take_next_instance, take_next_instance_w_condition.
Examples
let domain_participant = DomainParticipant::new(0).unwrap();
let qos = QosPolicyBuilder::new().build();
let subscriber = domain_participant.create_subscriber(&qos).unwrap();
// WithKey is important
let topic = domain_participant.create_topic("some_topic".to_string(), "SomeType".to_string(), &qos, TopicKind::WithKey).unwrap();
let mut data_reader = subscriber.create_datareader::<SomeType, CDRDeserializerAdapter<_>>(&topic, None).unwrap();
// Wait for data to arrive...
if let Ok(datas) = data_reader.take_instance(10, ReadCondition::any(), Some(3), SelectByKey::Next) {
for data in datas.iter() {
// do something
}
}
sourcepub fn wait_for_historical_data(&mut self, _max_wait: Duration) -> bool
pub fn wait_for_historical_data(&mut self, _max_wait: Duration) -> bool
Return values: true - got all historical data false - timeout before all historical data was received
pub fn get_matched_publications( &self ) -> impl Iterator<Item = PublicationBuiltinTopicData>
sourcepub fn async_sample_stream(self) -> DataReaderStream<D, DA>
pub fn async_sample_stream(self) -> DataReaderStream<D, DA>
An async stream for reading the (bare) data samples. The resulting Stream can be used to get another stream of status events.