<<interface>> Allows the application to: (1) declare the data it wishes to receive (i.e. make a subscription) and (2) access the data received by the attached DDSSubscriber. More...
Detailed Description
<<interface>> Allows the application to: (1) declare the data it wishes to receive (i.e. make a subscription) and (2) access the data received by the attached DDSSubscriber.
- Status:
- DDS_DATA_AVAILABLE_STATUS;
DDS_LIVELINESS_CHANGED_STATUS, DDS_LivelinessChangedStatus;
DDS_REQUESTED_DEADLINE_MISSED_STATUS, DDS_RequestedDeadlineMissedStatus;
DDS_REQUESTED_INCOMPATIBLE_QOS_STATUS, DDS_RequestedIncompatibleQosStatus;
DDS_SAMPLE_LOST_STATUS, DDS_SampleLostStatus;
DDS_SAMPLE_REJECTED_STATUS, DDS_SampleRejectedStatus;
DDS_SUBSCRIPTION_MATCHED_STATUS, DDS_SubscriptionMatchedStatus;
- Listener:
- DDSDataReaderListener
A DDSDataReader refers to exactly one DDSTopicDescription (either a DDSTopic, a DDSContentFilteredTopic or a DDSMultiTopic) that identifies the data to be read.
The subscription has a unique resulting type. The data-reader may give access to several instances of the resulting type, which can be distinguished from each other by their key.
DDSDataReader is an abstract class. It must be specialised for each particular application data-type (see USER_DATA). The additional methods or functions that must be defined in the auto-generated class for a hypothetical application type Foo are specified in the generic type FooDataReader.
The following operations may be called even if the DDSDataReader is not enabled. Other operations will fail with the value DDS_RETCODE_NOT_ENABLED if called on a disabled DDSDataReader:
- The base-class operations DDSDataReader::set_qos, DDSDataReader::get_qos, DDSDataReader::set_listener, DDSDataReader::get_listener, DDSEntity::enable, DDSEntity::get_statuscondition, DDSEntity::get_status_changes,
- DDSDataReader::get_liveliness_changed_status, DDSDataReader::get_requested_deadline_missed_status, DDSDataReader::get_requested_incompatible_qos_status, DDSDataReader::get_sample_lost_status, DDSDataReader::get_sample_rejected_status, DDSDataReader::get_subscription_matched_status
All sample-accessing operations, namely: FooDataReader::read, FooDataReader::take, FooDataReader::read_w_condition, and FooDataReader::take_w_condition may fail with the error DDS_RETCODE_PRECONDITION_NOT_MET as described in DDSSubscriber::begin_access.
- Examples:
- HelloWorld_subscriber.cxx, and HelloWorldSupport.cxx.
Member Function Documentation
◆ create_readcondition()
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inlinevirtual |
Creates a DDSReadCondition.
The returned DDSReadCondition will be attached and belong to the DDSDataReader.
- Parameters
-
sample_states <<in>> sample state of the data samples that are of interest view_states <<in>> view state of the data samples that are of interest instance_states <<in>> instance state of the data samples that are of interest
- Returns
- return DDSReadCondition created. Returns NULL in case of failure.
◆ create_readcondition_w_params()
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inlinevirtual |
<<extension>> Creates a DDSReadCondition with parameters.
The returned DDSReadCondition will be attached and belong to the DDSDataReader.
- Parameters
-
params <<in>> creation parameters.
- Returns
- return DDSReadCondition created. Returns NULL in case of failure.
◆ create_querycondition()
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inlinevirtual |
Creates a DDSQueryCondition.
The returned DDSQueryCondition will be attached and belong to the DDSDataReader.
Queries and Filters Syntax describes the syntax of query_expression and query_parameters.
- Parameters
-
sample_states <<in>> sample state of the data samples that are of interest view_states <<in>> view state of the data samples that are of interest instance_states <<in>> instance state of the data samples that are of interest query_expression <<in>> Expression for the query. Cannot be NULL. query_parameters <<in>> Parameters for the query expression.
- Returns
- return DDSQueryCondition created. Returns NULL in case of failure.
◆ create_querycondition_w_params()
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inlinevirtual |
<<extension>> Creates a DDSQueryCondition with parameters.
The returned DDSQueryCondition will be attached and belong to the DDSDataReader.
- Parameters
-
params <<in>> creation parameters.
- Returns
- return DDSQueryCondition created. Returns NULL in case of failure.
◆ delete_readcondition()
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inlinevirtual |
Deletes a DDSReadCondition or DDSQueryCondition attached to the DDSDataReader.
Since DDSQueryCondition specializes DDSReadCondition, it can also be used to delete a DDSQueryCondition.
- Precondition
- The DDSReadCondition must be attached to the DDSDataReader, or the operation will fail with the error DDS_RETCODE_PRECONDITION_NOT_MET.
- MT Safety:
- UNSAFE. It is not safe to delete an entity while another thread may be simultaneously calling an API that uses the entity.
- Parameters
-
condition <<in>> Condition to be deleted.
- Returns
- One of the Standard Return Codes, or DDS_RETCODE_PRECONDITION_NOT_MET
◆ delete_contained_entities()
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inlinevirtual |
Deletes all the entities that were created by means of the "create" operations on the DDSDataReader.
Deletes all contained DDSReadCondition, DDSQueryCondition, and DDSTopicQuery objects.
The operation will fail with DDS_RETCODE_PRECONDITION_NOT_MET if the any of the contained entities is in a state where it cannot be deleted.
Once DDSDataReader::delete_contained_entities completes successfully, the application may delete the DDSDataReader.
- MT Safety:
- UNSAFE. It is not safe to delete an entity while another thread may be simultaneously calling an API that uses the entity.
- Returns
- One of the Standard Return Codes, or DDS_RETCODE_PRECONDITION_NOT_MET
◆ wait_for_historical_data()
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Waits until all "historical" data is received for DDSDataReader entities that have a non-VOLATILE Durability Qos kind.
This operation is intended only for DDSDataReader entities that have a non-VOLATILE Durability QoS kind.
As soon as an application enables a non-VOLATILE DDSDataReader, it will start receiving both "historical" data (i.e., the data that was written prior to the time the DDSDataReader joined the domain) as well as any new data written by the DDSDataWriter entities. There are situations where the application logic may require the application to wait until all "historical" data is received. This is the purpose of the DDSDataReader::wait_for_historical_data operations.
DDSDataReader::wait_for_historical_data() blocks the calling thread until either all "historical" data is received, or until the duration specified by the max_wait parameter elapses, whichever happens first. It will return immediately if no DataWriters have been discovered at the time the operation is called; therefore it is advisable to make sure at least one DDSDataWriter has been discovered before calling this operation. (One way to do this is by using DDSDataReader::get_subscription_matched_status.)
A successful completion indicates that all the "historical" data was "received"; timing out indicates that max_wait elapsed before all the data was received.
- Parameters
-
max_wait <<in>> Timeout value.
- Returns
- One of the Standard Return Codes, DDS_RETCODE_TIMEOUT or DDS_RETCODE_NOT_ENABLED.
◆ acknowledge_sample() [1/2]
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<<extension>> Acknowledges a single sample explicitly.
Applicable only when DDS_ReliabilityQosPolicy::acknowledgment_kind = DDS_APPLICATION_EXPLICIT_ACKNOWLEDGMENT_MODE
A call to this method does not necessarily trigger the sending of an AppAck RTPS message from the DataReader to the DataWriter. How and when AppAck messages are sent can be configured using the QoS values DDS_RtpsReliableReaderProtocol_t::samples_per_app_ack and DDS_RtpsReliableReaderProtocol_t::app_ack_period.
- Parameters
-
sample_info <<in>> DDS_SampleInfo identifying the sample being acknowledged.
- Returns
- One of the Standard Return Codes
◆ acknowledge_all() [1/2]
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inlinevirtual |
<<extension>> Acknowledges all previously accessed samples.
Applicable only when DDS_ReliabilityQosPolicy::acknowledgment_kind = DDS_APPLICATION_EXPLICIT_ACKNOWLEDGMENT_MODE
A call to this method does not necessarily trigger the sending of an AppAck RTPS message from the DataReader to the DataWriter. How and when AppAck messages are sent can be configured using the QoS values DDS_RtpsReliableReaderProtocol_t::samples_per_app_ack and DDS_RtpsReliableReaderProtocol_t::app_ack_period.
- Returns
- One of the Standard Return Codes
◆ acknowledge_sample() [2/2]
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inlinevirtual |
<<extension>> Acknowledges a single sample explicitly.
Applicable only when DDS_ReliabilityQosPolicy::acknowledgment_kind = DDS_APPLICATION_EXPLICIT_ACKNOWLEDGMENT_MODE
A call to this method does not necessarily trigger the sending of an AppAck RTPS message from the DataReader to the DataWriter. How and when AppAck messages are sent can be configured using the QoS values DDS_RtpsReliableReaderProtocol_t::samples_per_app_ack and DDS_RtpsReliableReaderProtocol_t::app_ack_period.
The maximum length of the response is configured using DDS_DataReaderResourceLimitsQosPolicy::max_app_ack_response_length
- Parameters
-
sample_info <<in>> DDS_SampleInfo identifying the sample being acknowledged. response_data <<in>> Response data sent to DDSDataWriter upon acknowledgment (via DDSDataWriterListener::on_application_acknowledgment)
- Returns
- One of the Standard Return Codes
◆ acknowledge_all() [2/2]
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inlinevirtual |
<<extension>> Acknowledges all previously accessed samples.
Applicable only when DDS_ReliabilityQosPolicy::acknowledgment_kind = DDS_APPLICATION_EXPLICIT_ACKNOWLEDGMENT_MODE
A call to this method does not necessarily trigger the sending of an AppAck RTPS message from the DataReader to the DataWriter. How and when AppAck messages are sent can be configured using the QoS values DDS_RtpsReliableReaderProtocol_t::samples_per_app_ack and DDS_RtpsReliableReaderProtocol_t::app_ack_period.
The maximum length of the response is configured using DDS_DataReaderResourceLimitsQosPolicy::max_app_ack_response_length.
- Parameters
-
response_data <<in>> Response data sent to DDSDataWriter upon acknowledgment
- Returns
- One of the Standard Return Codes
◆ get_matched_publications()
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inlinevirtual |
Retrieves the list of publications currently "associated" with this DDSDataReader.
A publication is considered to be matching if all of the following criteria are true:
- The publication is within the same domain as this subscription.
- The publication has a matching DDSTopic.
- The publication has compatible QoS.
- If the applications are using partitions, the publication shares a common partition with this subscription.
- The DDSDomainParticipant has not indicated that the publication's DDSDomainParticipant should be "ignored" by means of the DDSDomainParticipant::ignore_publication API.
- If the subscription is using a DDSContentFilteredTopic and the publication is using the DDS_MultiChannelQosPolicy, there is an intersection between at least one of the associated filters.
- If the endpoints need to exchange key material to communicate (i.e., they are securing their communications), the reader has completed the key exchange with the writer.
The handles returned in the publication_handles list are the ones that are used by the RTI Connext implementation to locally identify the corresponding matched DDSDataWriter entities. These handles match the ones that appear in the instance_handle field of the DDS_SampleInfo when reading the DDS_PUBLICATION_TOPIC_NAME builtin topic.
This API may return the publication handles of publications that are not alive. DDSDataReader::is_matched_publication_alive can be used to check the liveliness of the remote publication.
- Parameters
-
publication_handles <<inout>>. The sequence will be grown if the sequence has ownership and the system has the corresponding resources. Use a sequence without ownership to avoid dynamic memory allocation. If the sequence is too small to store all of the matches and the system cannot resize the sequence, this method will fail with DDS_RETCODE_OUT_OF_RESOURCES. The maximum number of matches possible is configured with DDS_DomainParticipantResourceLimitsQosPolicy. You can use a zero-maximum sequence without ownership to quickly check whether there are any matches without allocating any memory.
- Returns
- One of the Standard Return Codes, or DDS_RETCODE_OUT_OF_RESOURCES if the sequence is too small and the system cannot resize it, or DDS_RETCODE_NOT_ENABLED
◆ get_matched_publication_data()
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inlinevirtual |
Retrieves the information on a publication that is currently "associated" with the DDSDataReader.
The publication_handle must correspond to a publication currently associated with the DDSDataReader. Otherwise, the operation will fail with DDS_RETCODE_BAD_PARAMETER. Use the operation DDSDataReader::get_matched_publications to find the publications that are currently matched with the DDSDataReader.
Note: This operation does not retrieve the DDS_PublicationBuiltinTopicData::type_code. This information is available through DDSDataReaderListener::on_data_available() (if a reader listener is installed on the DDSPublicationBuiltinTopicDataDataReader).
- Parameters
-
publication_data <<inout>>. The information to be filled in on the associated publication. Cannot be NULL. publication_handle <<in>>. Handle to a specific publication associated with the DDSDataWriter. Must correspond to a publication currently associated with the DDSDataReader.
- Returns
- One of the Standard Return Codes or DDS_RETCODE_NOT_ENABLED
◆ is_matched_publication_alive()
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inlinevirtual |
Check if a publication currently matched with a DataReader is alive.
This API is used for querying the endpoint liveliness of a matched publication. A matched publication will be marked as not alive if the liveliness that it committed to through its LIVELINESS QoS policy was not respected. Note that if the participant associated with the matched publication loses liveliness, the DDS_InstanceHandle_t will become invalid and this function will fail with DDS_RETCODE_BAD_PARAMETER.
- Parameters
-
publication_handle <<in>> The DDS_InstanceHandle_t of the matched publication. See DDSDataReader::get_matched_publications for a description of what is considered a matched publication. is_alive <<out>> Indicates whether or not the matched publication is alive.
- Returns
- One of the Standard Return Codes
◆ get_matched_publication_participant_data()
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inlinevirtual |
<<extension>> Retrieves the information on the discovered DDSDomainParticipant associated with the publication that is currently matching with the DDSDataReader.
The publication_handle must correspond to a publication currently associated with the DDSDataReader. Otherwise, the operation will fail with DDS_RETCODE_BAD_PARAMETER. The operation may also fail with DDS_RETCODE_PRECONDITION_NOT_MET if the publication corresponds to the same DDSDomainParticipant that the DataReader belongs to. Use the operation DDSDataReader::get_matched_publications to find the publications that are currently matched with the DDSDataReader.
- Parameters
-
participant_data <<inout>>. The information to be filled in on the associated participant. Cannot be NULL. publication_handle <<in>>. Handle to a specific publication associated with a DDSDataWriter. Must correspond to a publication currently associated with the DDSDataReader.
- Returns
- One of the Standard Return Codes or DDS_RETCODE_NOT_ENABLED
◆ get_topicdescription()
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inlinevirtual |
Returns the DDSTopicDescription associated with the DDSDataReader.
Returns that same DDSTopicDescription that was used to create the DDSDataReader.
- Returns
- DDSTopicDescription associated with the DDSDataReader.
◆ get_subscriber()
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inlinevirtual |
Returns the DDSSubscriber to which the DDSDataReader belongs.
- Returns
- DDSSubscriber to which the DDSDataReader belongs.
◆ get_sample_rejected_status()
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inlinevirtual |
Accesses the DDS_SAMPLE_REJECTED_STATUS communication status.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_SampleRejectedStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_liveliness_changed_status()
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inlinevirtual |
Accesses the DDS_LIVELINESS_CHANGED_STATUS communication status.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_LivelinessChangedStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_requested_deadline_missed_status()
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inlinevirtual |
Accesses the DDS_REQUESTED_DEADLINE_MISSED_STATUS communication status.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_RequestedDeadlineMissedStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_requested_incompatible_qos_status()
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inlinevirtual |
Accesses the DDS_REQUESTED_INCOMPATIBLE_QOS_STATUS communication status.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_RequestedIncompatibleQosStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_sample_lost_status()
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inlinevirtual |
Accesses the DDS_SAMPLE_LOST_STATUS communication status.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_SampleLostStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_subscription_matched_status()
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inlinevirtual |
Accesses the DDS_SUBSCRIPTION_MATCHED_STATUS communication status.
- Parameters
-
status <<inout>> DDS_SubscriptionMatchedStatus to be filled in.
- Returns
- One of the Standard Return Codes
◆ get_datareader_cache_status()
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inlinevirtual |
<<extension>> Gets the datareader cache status for this reader.
- Parameters
-
status <<inout>> DDS_DataReaderCacheStatus to be filled in.
- Returns
- One of the Standard Return Codes or DDS_RETCODE_NOT_ENABLED.
◆ get_datareader_protocol_status()
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inlinevirtual |
<<extension>> Gets the datareader protocol status for this reader.
This also resets the status so that it is no longer considered changed.
- Parameters
-
status <<inout>> DDS_DataReaderProtocolStatus to be filled in.
- Returns
- One of the Standard Return Codes or DDS_RETCODE_NOT_ENABLED.
◆ get_matched_publication_datareader_protocol_status()
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inlinevirtual |
<<extension>> Gets the datareader protocol status for this reader, per matched publication identified by the publication_handle.
This also resets the status so that it is no longer considered changed.
Note: Status for a remote entity is only kept while the entity is alive. Once a remote entity is no longer alive, its status is deleted.
- Parameters
-
status <<inout>>. The information to be filled in on the associated publication. Cannot be NULL. publication_handle <<in>>. Handle to a specific publication associated with the DDSDataWriter.. Must correspond to a publication currently associated with the DDSDataReader.
- Returns
- One of the Standard Return Codes or DDS_RETCODE_NOT_ENABLED
◆ set_qos()
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inlinevirtual |
Sets the reader QoS.
Modifies the QoS of the DDSDataReader.
The DDS_DataReaderQos::user_data, DDS_DataReaderQos::deadline, DDS_DataReaderQos::latency_budget, DDS_DataReaderQos::time_based_filter, DDS_DataReaderQos::reader_data_lifecycle can be changed. The other policies are immutable.
- Parameters
-
qos <<in>> The DDS_DataReaderQos to be set to. Policies must be consistent. Immutable policies cannot be changed after DDSDataReader is enabled. The special value DDS_DATAREADER_QOS_DEFAULT can be used to indicate that the QoS of the DDSDataReader should be changed to match the current default DDS_DataReaderQos set in the DDSSubscriber.
- Returns
- One of the Standard Return Codes, DDS_RETCODE_IMMUTABLE_POLICY, or DDS_RETCODE_INCONSISTENT_POLICY.
- See also
- DDS_DataReaderQos for rules on consistency among QoS
- set_qos (abstract)
- DDSDataReader::set_qos
- Operations Allowed in Listener Callbacks
◆ get_qos()
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inlinevirtual |
Gets the reader QoS.
This method may potentially allocate memory depending on the sequences contained in some QoS policies.
- Parameters
-
qos <<inout>> The DDS_DataReaderQos to be filled up.
- Returns
- One of the Standard Return Codes
- See also
- get_qos (abstract)
◆ set_qos_with_profile()
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inlinevirtual |
<<extension>> Changes the QoS of this reader using the input XML QoS profile.
This operation modifies the QoS of the DDSDataReader.
The DDS_DataReaderQos::user_data, DDS_DataReaderQos::deadline, DDS_DataReaderQos::latency_budget, DDS_DataReaderQos::time_based_filter, DDS_DataReaderQos::reader_data_lifecycle can be changed. The other policies are immutable.
- Parameters
-
library_name <<in>> Library name containing the XML QoS profile. If library_name is null RTI Connext will use the default library (see DDSSubscriber::set_default_library). profile_name <<in>> XML QoS Profile name. If profile_name is null RTI Connext will use the default profile (see DDSSubscriber::set_default_profile).
- Returns
- One of the Standard Return Codes, DDS_RETCODE_IMMUTABLE_POLICY, or DDS_RETCODE_INCONSISTENT_POLICY.
- See also
- DDS_DataReaderQos for rules on consistency among QoS
- DDSDataReader::set_qos
- Operations Allowed in Listener Callbacks
◆ set_property()
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inlinevirtual |
Set the value for a property that applies to a DataReader.
- Parameters
-
property_name <<in>>. Name of the property that you want to set. value <<in>>. New value for the property. propagate <<in>>. Indicates if the property will be propagated or not.
- Returns
- One of the Standard Return Codes
◆ set_listener()
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inlinevirtual |
Sets the reader listener.
- Parameters
-
l <<in>> DDSDataReaderListener to set to mask <<in>> DDS_StatusMask associated with the DDSDataReaderListener.
- Returns
- One of the Standard Return Codes
- See also
- set_listener (abstract)
◆ get_listener()
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inlinevirtual |
Gets the reader listener.
- Returns
- DDSDataReaderListener of the DDSDataReader.
- See also
- get_listener (abstract)
◆ create_topic_query()
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inlinevirtual |
Creates a DDSTopicQuery.
The returned DDSTopicQuery will have been issued if the DDSDataReader is enabled. Otherwise, the DDSTopicQuery will be issued once the DDSDataReader is enabled
- Parameters
-
selection <<in>> The selection with which to create the DDSTopicQuery. The special values DDS_TOPIC_QUERY_SELECTION_SELECT_ALL and DDS_TOPIC_QUERY_SELECTION_USE_READER_CONTENT_FILTER can be used. The expression can start with the special condition "@instance_state = ALIVE AND" followed by the rest of the expression. This restricts the selection to samples of alive instances.
- Returns
- return Created DDSTopicQuery. Returns NULL in case of failure.
◆ delete_topic_query()
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inlinevirtual |
Deletes a DDSTopicQuery.
Cancels an active DDSTopicQuery. After deleting a TopicQuery, new DataWriters won't discover it and existing DataWriters currently publishing cached samples may stop before delivering all of them.
- Parameters
-
query <<in>> The DDSTopicQuery to delete.
- Returns
- One of the Standard Return Codes
◆ lookup_topic_query()
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inlinevirtual |
Retrieves an existing DDSTopicQuery.
Retrieves the DDSTopicQuery that corresponds to the input DDS_GUID_t.
If no TopicQuery is found for the specified GUID or the TopicQuery is marked for deletion, this returns NULL.
To get the DDS_GUID_t associated with a DDSTopicQuery, use the method DDSTopicQuery::get_guid.
- Parameters
-
guid <<in>> The DDSTopicQuery GUID.
◆ take_discovery_snapshot() [1/2]
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inlinevirtual |
Take a snapshot of the compatible and incompatible remote writers matched by a local reader.
The snapshot will be printed through the NDDSConfigLogger. A possible output may be the following:
- Returns
- One of the Standard Return Codes.
◆ take_discovery_snapshot() [2/2]
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inlinevirtual |
Take a snapshot of the compatible and incompatible remote writers matched by a local reader.
The snapshot will be printed in the file specified by file_name. A possible output may be the following:
- Parameters
-
file_name <<in>> Name of the file where snapshot should be printed.
- Returns
- One of the Standard Return Codes.
◆ enable()
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inlinevirtual |
Enables the DDSEntity.
This operation enables the Entity. Entity objects can be created either enabled or disabled. This is controlled by the value of the ENTITY_FACTORY QoS policy on the corresponding factory for the DDSEntity.
By default, ENTITY_FACTORY is set so that it is not necessary to explicitly call DDSEntity::enable on newly created entities.
The DDSEntity::enable operation is idempotent. Calling enable on an already enabled Entity returns OK and has no effect.
If a DDSEntity has not yet been enabled, the following kinds of operations may be invoked on it:
- set or get the QoS policies (including default QoS policies) and listener
- DDSEntity::get_statuscondition
- 'factory' operations
- DDSEntity::get_status_changes and other get status operations (although the status of a disabled entity never changes)
- 'lookup' operations
Other operations may explicitly state that they may be called on disabled entities; those that do not will return the error DDS_RETCODE_NOT_ENABLED.
It is legal to delete an DDSEntity that has not been enabled by calling the proper operation on its factory.
Entities created from a factory Entity that is disabled are created disabled, regardless of the setting of the DDS_EntityFactoryQosPolicy.
Calling enable on an Entity whose factory Entity is not enabled will fail and return DDS_RETCODE_PRECONDITION_NOT_MET.
If DDS_EntityFactoryQosPolicy::autoenable_created_entities is TRUE, the enable operation on a factory will automatically enable all entities created from that factory (for example, enabling a DDSPublisher will enable all its contained DDSDataWriter objects)
Listeners associated with an entity are not called until the entity is enabled.
Conditions associated with a disabled entity are "inactive," that is, they have a trigger_value == FALSE.
- Returns
- One of the Standard Return Codes, Standard Return Codes or DDS_RETCODE_PRECONDITION_NOT_MET.
Implements DDSEntity.
◆ get_statuscondition()
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inlinevirtual |
Allows access to the DDSStatusCondition associated with the DDSEntity.
The returned condition can then be added to a DDSWaitSet so that the application can wait for specific status changes that affect the DDSEntity.
- Returns
- the status condition associated with this entity.
Implements DDSEntity.
◆ get_status_changes()
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inlinevirtual |
Retrieves the list of communication statuses in the DDSEntity that are triggered.
That is, the list of statuses whose value has changed since the last time the application read the status using the get_*_status() method.
When the entity is first created or if the entity is not enabled, all communication statuses are in the "untriggered" state so the list returned by the get_status_changes operation will be empty.
The list of statuses returned by the get_status_changes operation refers to the status that are triggered on the Entity itself and does not include statuses that apply to contained entities.
- Returns
- list of communication statuses in the DDSEntity that are triggered.
- See also
- Status Kinds
Implements DDSEntity.
◆ get_instance_handle()
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inlinevirtual |
Allows access to the DDS_InstanceHandle_t associated with the DDSEntity.
This operation returns the DDS_InstanceHandle_t that represents the DDSEntity.
- Returns
- the instance handle associated with this entity.
Implements DDSEntity.
References DDS_BOOLEAN_FALSE.