Make the trigger of the DDS Pipe callbacks configurable

ddspipe_core/include/ddspipe_core/configuration/DdsPipeConfiguration.hpp

@@ -18,6 +18,7 @@
 #include <set>
 
 #include <cpp_utils/Formatter.hpp>
+#include <cpp_utils/macros/custom_enumeration.hpp>
 
 #include <ddspipe_core/configuration/IConfiguration.hpp>
 #include <ddspipe_core/configuration/RoutesConfiguration.hpp>
@@ -32,6 +33,15 @@ namespace eprosima {
 namespace ddspipe {
 namespace core {
 
+//! Possible kinds of discovery triggers
+ENUMERATION_BUILDER(
+    DiscoveryTrigger,
+    READER,     //! The discovery callbacks get triggered by the discovery of a reader.
+    WRITER,     //! The discovery callbacks get triggered by the discovery of a writer.
+    NONE,       //! The discovery callbacks don't get triggered by the discovery of readers or writers.
+    ANY         //! The discovery callbacks get triggered by the discovery of either a reader or a writer.
+    );
+
 /**
  * Configuration structure encapsulating the configuration of a \c DdsPipe instance.
  */
@@ -108,6 +118,9 @@ struct DdsPipeConfiguration : public IConfiguration
 
     //! Whether the DDS Pipe should be initialized enabled.
     bool init_enabled = false;
+
+    //! The type of the entity whose discovery should trigger the discovery callbacks.
+    DiscoveryTrigger discovery_trigger = DiscoveryTrigger::READER;
 };
 
 } /* namespace core */

ddspipe_core/include/ddspipe_core/core/DdsPipe.hpp

@@ -213,9 +213,26 @@ class DdsPipe
             const types::Endpoint& endpoint) noexcept;
 
     /**
-     * @brief Method called every time a new endpoint has been discovered, removed, or updated.
+     * @brief Check whether the kind of an endpoint matches the discovery trigger kind.
+     *
+     * Method called every time a new endpoint has been discovered, removed, or updated.
+     *
+     * @param [in] endpoint : endpoint discovered, removed, or updated.
+     *
+     * @return Whether the endpoint's kind matches the discovery trigger.
+     */
+    bool is_endpoint_kind_relevant_(
+            const types::Endpoint& endpoint) noexcept;
+
+    /**
+     * @brief Check whether an endpoint is the first endpoint discovered or the last removed.
+     *
+     * Method called every time a new endpoint has been discovered, removed, or updated.
+     * This method calls \c is_endpoint_kind_relevant_
      *
      * @param [in] endpoint : endpoint discovered, removed, or updated.
+     *
+     * @return Whether the DdsPipe's discovery callbacks need to process the endpoint.
      */
     bool is_endpoint_relevant_(
             const types::Endpoint& endpoint) noexcept;

ddspipe_core/src/cpp/configuration/DdsPipeConfiguration.cpp

@@ -29,6 +29,12 @@ namespace core {
 bool DdsPipeConfiguration::is_valid(
         utils::Formatter& error_msg) const noexcept
 {
+    if (remove_unused_entities && discovery_trigger != DiscoveryTrigger::READER)
+    {
+        error_msg << "A discovery-trigger different from reader is incompatible with remove-unused-entities.";
+        return false;
+    }
+
     return routes.is_valid(error_msg) && topic_routes.is_valid(error_msg);
 }
 

ddspipe_core/src/cpp/core/DdsPipe.cpp

@@ -19,6 +19,7 @@
 #include <cpp_utils/exception/InitializationException.hpp>
 #include <cpp_utils/exception/InconsistencyException.hpp>
 #include <cpp_utils/Log.hpp>
+#include <cpp_utils/utils.hpp>
 
 #include <ddspipe_core/core/DdsPipe.hpp>
 
@@ -80,9 +81,6 @@ DdsPipe::DdsPipe(
     }
 
     // Init discovery database
-    // The entities should not be added to the Discovery Database until the builtin topics have been created.
-    // This is due to the fact that the Participants endpoints start discovering topics with different configuration
-    // than the one specified in the yaml configuration file.
     discovery_database_->start();
 
     logDebug(DDSPIPE, "DDS Pipe created.");
@@ -284,7 +282,7 @@ void DdsPipe::discovered_endpoint_nts_(
 
     if (RpcTopic::is_service_topic(endpoint.topic))
     {
-        if (endpoint.is_reader() && endpoint.is_server_endpoint())
+        if (is_endpoint_kind_relevant_(endpoint) && endpoint.is_server_endpoint())
         {
             // Service server discovered
             discovered_service_nts_(RpcTopic(
@@ -347,18 +345,41 @@ void DdsPipe::updated_endpoint_nts_(
     }
 }
 
+bool DdsPipe::is_endpoint_kind_relevant_(
+        const Endpoint& endpoint) noexcept
+{
+    switch (configuration_.discovery_trigger)
+    {
+        case DiscoveryTrigger::READER:
+            return endpoint.is_reader();
+
+        case DiscoveryTrigger::WRITER:
+            return endpoint.is_writer();
+
+        case DiscoveryTrigger::ANY:
+            return true;
+
+        case DiscoveryTrigger::NONE:
+            return false;
+
+        default:
+            utils::tsnh(utils::Formatter() << "Invalid Discovery Trigger.");
+            return false;
+    }
+}
+
 bool DdsPipe::is_endpoint_relevant_(
         const Endpoint& endpoint) noexcept
 {
-    if (!endpoint.is_reader())
+    if (!is_endpoint_kind_relevant_(endpoint))
     {
         return false;
     }
 
-    auto is_endpoint_relevant = [endpoint](const Endpoint& entity)
+    auto is_endpoint_relevant = [&](const Endpoint& entity)
             {
                 return entity.active &&
-                       entity.is_reader() &&
+                       is_endpoint_kind_relevant_(entity) &&
                        entity.topic == endpoint.topic &&
                        entity.discoverer_participant_id == endpoint.discoverer_participant_id;
             };

ddspipe_participants/src/cpp/participant/dynamic_types/SchemaParticipant.cpp

@@ -47,25 +47,6 @@ SchemaParticipant::SchemaParticipant(
     , discovery_database_(discovery_database)
     , schema_handler_(schema_handler)
 {
-    // Simulate that there is a reader of type object to force this track creation
-    discovery_database_->add_endpoint(
-        rtps::CommonParticipant::simulate_endpoint(type_object_topic(), this->id())
-        );
-
-    // Force for every topic found to create track by creating simulated readers
-    // NOTE: this could change for: in DDS Pipe change that only readers create track
-    discovery_database_->add_endpoint_discovered_callback(
-        [this](Endpoint endpoint_discovered)
-        {
-            if (endpoint_discovered.is_writer() && endpoint_discovered.discoverer_participant_id != this->id())
-            {
-                discovery_database_->add_endpoint(
-                    rtps::CommonParticipant::simulate_endpoint(endpoint_discovered.topic,
-                    endpoint_discovered.discoverer_participant_id)
-                    );
-            }
-        }
-        );
 }
 
 ParticipantId SchemaParticipant::id() const noexcept

ddspipe_yaml/include/ddspipe_yaml/yaml_configuration_tags.hpp

@@ -141,6 +141,7 @@ constexpr const char* SPECS_QOS_TAG("qos"); //! Global Topic QoS
 constexpr const char* NUMBER_THREADS_TAG("threads"); //! Number of threads to configure the thread pool
 constexpr const char* WAIT_ALL_ACKED_TIMEOUT_TAG("wait-all-acked-timeout"); //! Wait for a maximum of *wait-all-acked-timeout* ms until all msgs sent by reliable writers are acknowledged by their matched readers
 constexpr const char* REMOVE_UNUSED_ENTITIES_TAG("remove-unused-entities"); //! Dynamically create and delete entities and tracks.
+constexpr const char* DISCOVERY_TRIGGER_TAG("discovery-trigger"); //! Make the trigger of the DDS Pipe callbacks configurable.
 
 // XML configuration tags
 constexpr const char* XML_TAG("xml"); //! Tag to read xml configuration