Send only non-default QoS & Use 'serialize_optional_qos' for optional QoS in EDP messages (#1065)

* Refs #23078: Document new property

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

* Refs #23078: Review

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

---------

Signed-off-by: cferreiragonz <carlosferreira@eprosima.com>

Author: cferreiragonz

code/DDSCodeTester.cpp

@@ -981,6 +981,16 @@ void dds_domain_examples()
             "disabled");
         //!--
     }
+
+    {
+        // SERIALIZE_OPTIONAL_QOS_PROPERTY
+        DomainParticipantQos pqos;
+
+        pqos.properties().properties().emplace_back(
+            "fastdds.serialize_optional_qos",
+            "True");
+        //!--
+    }
 }
 
 //DOMAINPARTICIPANTLISTENER-DISCOVERY-CALLBACKS
@@ -2062,7 +2072,7 @@ void dds_topic_examples()
         include_paths.push_back("<path/to/folder/containing/included/idl/files>");
 
         // Retrieve the instance of the desired type
-        DynamicTypeBuilder::_ref_type dyn_type_builder = 
+        DynamicTypeBuilder::_ref_type dyn_type_builder =
                 DynamicTypeBuilderFactory::get_instance()->create_type_w_uri(idl_file, type_name, include_paths);
 
         // Register dynamic type
@@ -7937,7 +7947,7 @@ void rpcdds_internal_api_examples()
             // Error
             return;
         }
- 
+
         // Wait for some time until a Reply sample is received
         requester->get_requester_reader()->wait_for_unread_message(Duration_t{3,0});
 
@@ -7948,12 +7958,12 @@ void rpcdds_internal_api_examples()
             // Error
             return;
         }
-    
+
         if (expected_request_info.related_sample_identity == received_request_info.related_sample_identity)
         {
           // Received Reply sample is associated to the sent Request sample
         }
-    
+
         // Delete created Requester
         ret = participant->delete_service_requester(requester->get_service_name(), requester);
         if (RETCODE_OK != ret)

code/XMLTester.xml

@@ -3293,6 +3293,30 @@
 -->
 <!--><-->
 
+<!-->SERIALIZE_OPTIONAL_QOS_PROPERTY<-->
+<!--
+<?xml version="1.0" encoding="UTF-8" ?>
+<dds xmlns="http://www.eprosima.com">
+    <profiles>
+-->
+        <participant profile_name="serialize_optional_qos_domainparticipant_xml_profile">
+            <rtps>
+                <propertiesPolicy>
+                    <properties>
+                        <property>
+                            <name>fastdds.serialize_optional_qos</name>
+                            <value>True</value>
+                        </property>
+                    </properties>
+                </propertiesPolicy>
+            </rtps>
+        </participant>
+<!--
+    </profiles>
+</dds>
+-->
+<!--><-->
+
 <!-->FASTDDS_STATISTICS_MODULE<-->
 <participant profile_name="statistics_domainparticipant_conf_xml_profile">
     <rtps>

docs/fastdds/property_policies/non_consolidated_qos.rst

@@ -474,3 +474,68 @@ The different property values have the following effects on the local |DomainPar
         :start-after: <!-->TYPE_PROPAGATION_PROPERTY<-->
         :end-before: <!--><-->
         :lines: 2-4,6-17,19-20
+
+.. _property_serialize_optional_qos:
+
+Adding optional QoS to Discovery data
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+During the Endpoint Discovery Phase (EDP), |DataWriters-api| and |DataReaders-api| acknowledge each other.
+To do that, the DomainParticipants share information about their DataWriters and DataReaders with each other,
+using the communication channels established during the PDP.
+This information contains all data required to match the endpoints, such as the |Topic-api|, data type, and
+certain :ref:`QoS Policies <dds_layer_core_policy>` that might affect matching.
+Specific compatibility rules can be found in each QoS section of :ref:`QoS Policies <dds_layer_core_policy>`.
+
+However, there are some QoS that are not mandatory for matching, but can be useful to have in the EDP messages.
+Property ``fastdds.serialize_optional_qos`` allows the user to include these optional QoS in the EDP messages.
+This property is configured at the |DomainParticipant-api| level through the policy :ref:`propertypolicyqos`.
+Hence, all associated endpoints to that |DomainParticipant-api| will send their optional QoS in the EDP messages.
+
+Optional QoS, like any other QoS, will only be serialized if they have non-default values.
+Not receiving information about a QoS in the EDP message means that it has a default value.
+Optional QoS will be serialized if the value of the property is set to ``TRUE``, ``True``, ``true`` or ``1``, any
+other value will be considered as not set or ``FALSE``.
+
+The following table lists all the optional QoS that can be serialized in the EDP messages:
+
+.. list-table::
+   :header-rows: 1
+   :align: left
+
+   * - PropertyPolicyQos
+     - Applies to:
+   * - |ResourceLimitsQosPolicy-api|
+     - |DataWriter-api| and |DataReaders-api|.
+   * - |TransportPriorityQosPolicy-api|
+     - |DataWriter-api|.
+   * - |WriterDataLifecycleQosPolicy-api|
+     - |DataWriter-api|.
+   * - |ReaderDataLifecycleQosPolicy-api|
+     - |DataReaders-api|.
+   * - |PublishModeQosPolicy-api|
+     - |DataWriter-api|.
+   * - |RTPSReliableWriterQos-api|
+     - |DataWriter-api|.
+   * - |RTPSReliableReaderQos-api|
+     - |DataReaders-api|.
+   * - |RTPSEndpointQos-api|
+     - |DataWriter-api| and |DataReaders-api|.
+   * - |WriterResourceLimitsQos-api|
+     - |DataWriter-api|.
+   * - |ReaderResourceLimitsQos-api|
+     - |DataReaders-api|.
+
+.. tab-set-code::
+
+    .. literalinclude:: /../code/DDSCodeTester.cpp
+        :language: c++
+        :start-after: // SERIALIZE_OPTIONAL_QOS_PROPERTY
+        :end-before: //!--
+        :dedent: 8
+
+    .. literalinclude:: /../code/XMLTester.xml
+        :language: xml
+        :start-after: <!-->SERIALIZE_OPTIONAL_QOS_PROPERTY<-->
+        :end-before: <!--><-->
+        :lines: 2-4,6-17,19-20