Handle cancel active diag requet when there are no more subscribers

When push events if there is no more subscribers to that event then call
a function that will cleanup that request from diagnostic manager queue.

Change-Id: I8153701074453444a5bba6f1374401bdf230f7e6
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

5 files changed, 48 insertions, 23 deletions

diff --git a/src/can/can-bus.cpp b/src/can/can-bus.cpp
index ee70744e..33f58fd9 100644
--- a/src/can/can-bus.cpp
+++ b/src/can/can-bus.cpp
@@ -185,7 +185,8 @@ void can_bus_t::can_event_push()
 				{
 					jo = json_object_new_object();
 					jsonify_simple(s_message, jo);
-					afb_event_push(s[std::string(s_message.name)], jo);
+					if(afb_event_push(s[std::string(s_message.name)], jo) == 0)
+						on_no_clients(std::string(s_message.name));
 				}
 			}
 		}
diff --git a/src/configuration.cpp b/src/configuration.cpp
index 184d4688..32cb00cd 100644
--- a/src/configuration.cpp
+++ b/src/configuration.cpp
@@ -18,6 +18,7 @@
 #include "configuration.hpp"
 
 #include "utils/signals.hpp"
+#include "utils/openxc-utils.hpp"
 
 /// @brief Return singleton instance of configuration object.
 configuration_t& configuration_t::instance()
@@ -109,6 +110,23 @@ void configuration_t::find_diagnostic_messages(const openxc_DynamicField &key, s
 	DEBUG(binder_interface, "find_diagnostic_messages: Found %d signal(s)", (int)found_signals.size());
 }
 
+diagnostic_message_t* configuration_t::get_diagnostic_message(std::string message_name) const
+{
+	std::vector<diagnostic_message_t*> found;
+	configuration_t::instance().find_diagnostic_messages(build_DynamicField(message_name), found);
+	return found.front();
+}
+
+DiagnosticRequest* configuration_t::get_request_from_diagnostic_message(diagnostic_message_t* diag_msg) const
+{
+	return new DiagnosticRequest(diag_msg->build_diagnostic_request());
+}
+
+DiagnosticRequest* configuration_t::get_request_from_diagnostic_message(std::string message_name) const
+{
+	return new DiagnosticRequest(get_diagnostic_message(message_name)->build_diagnostic_request());
+}
+
 /// @brief return signals name found searching through CAN signals list.
 ///
 /// @param[in] key - can contain numeric or string value in order to search against
diff --git a/src/configuration.hpp b/src/configuration.hpp
index 57eeef3d..017b148d 100644
--- a/src/configuration.hpp
+++ b/src/configuration.hpp
@@ -88,6 +88,9 @@ class configuration_t
 		void set_active_message_set(uint8_t id);
 
 		void find_diagnostic_messages(const openxc_DynamicField &key, std::vector<diagnostic_message_t*>& found_signals);
+		diagnostic_message_t* get_diagnostic_message(std::string message_name) const;
+		DiagnosticRequest* get_request_from_diagnostic_message(diagnostic_message_t* diag_msg) const;
+		DiagnosticRequest* get_request_from_diagnostic_message(std::string message_name) const;
 
 		void find_can_signals(const openxc_DynamicField &key, std::vector<can_signal_t*>& found_signals);
 
diff --git a/src/low-can-binding.cpp b/src/low-can-binding.cpp
index cee88a87..8fc143c5 100644
--- a/src/low-can-binding.cpp
+++ b/src/low-can-binding.cpp
@@ -45,6 +45,13 @@ extern "C"
 // Interface between the daemon and the binding
 const struct afb_binding_interface *binder_interface;
 
+void on_no_clients(std::string message)
+{
+	DiagnosticRequest* diag_req = configuration_t::instance().get_request_from_diagnostic_message(message);
+	active_diagnostic_request_t* adr = configuration_t::instance().get_diagnostic_manager().find_recurring_request(diag_req);
+	configuration_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
+}
+
 ///******************************************************************************
 ///
 ///		Subscription and unsubscription
@@ -60,7 +67,6 @@ static int make_subscription_unsubscription(struct afb_req request, const std::s
 		return 0;
 	}
 	return 1;
-
 }
 
 static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
@@ -129,29 +135,21 @@ static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe,
 	for(const std::string& sig : signals)
 	{
 		int ret;
+		bool to_subscribe = false;
 		if (active_diagnostic_request_t::is_diagnostic_signal(sig))
 		{
-			std::vector<diagnostic_message_t*> found;
-			configuration_t::instance().find_diagnostic_messages(build_DynamicField(sig), found);
-			DiagnosticRequest* diag_req = new DiagnosticRequest(found.front()->build_diagnostic_request());
+			diagnostic_message_t* diag_msg = configuration_t::instance().get_diagnostic_message(sig);
+			DiagnosticRequest* diag_req = configuration_t::instance().get_request_from_diagnostic_message(diag_msg);
 
 			// If the requested diagnostic message isn't supported by the car then unssubcribe.
 			// no matter what we want, worse case will be a fail unsubscription but at least we don't
 			// poll a PID for nothing.
-			if(found.front()->get_supported())
+			if(diag_msg->get_supported() && subscribe)
 			{
-				if(subscribe)
-				{
-					float frequency = found.front()->get_frequency();
-					configuration_t::instance().get_diagnostic_manager().add_recurring_request(
-						diag_req, sig.c_str(), false, found.front()->get_decoder(), found.front()->get_callback(), (float)frequency);
+					float frequency = diag_msg->get_frequency();
+					to_subscribe = configuration_t::instance().get_diagnostic_manager().add_recurring_request(
+						diag_req, sig.c_str(), false, diag_msg->get_decoder(), diag_msg->get_callback(), (float)frequency);
 						//TODO: Adding callback requesting ignition status:	diag_req, sig.c_str(), false, diagnostic_message_t::decode_obd2_response, diagnostic_message_t::check_ignition_status, frequency);
-				}
-				else
-				{
-					active_diagnostic_request_t* adr = configuration_t::instance().get_diagnostic_manager().find_recurring_request(diag_req);
-					configuration_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
-				}
 			}
 			else
 			{
@@ -162,11 +160,13 @@ static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe,
 			}
 		}
 
-		ret = subscribe_unsubscribe_signal(request, subscribe, sig);
-		if(ret <= 0)
-			return ret;
-
-		rets++;
+		if(to_subscribe)
+		{
+			ret = subscribe_unsubscribe_signal(request, subscribe, sig);
+			if(ret <= 0)
+				return ret;
+			rets++;
+		}
 		DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 	}
 	return rets;
diff --git a/src/low-can-binding.hpp b/src/low-can-binding.hpp
index 04c7eac4..ed5741d8 100644
--- a/src/low-can-binding.hpp
+++ b/src/low-can-binding.hpp
@@ -19,6 +19,7 @@
 #pragma once
 
 #include <cstddef>
+#include <string>
 
 extern "C"
 {
@@ -27,4 +28,6 @@ extern "C"
 
 extern "C" struct afb_binding_interface;
 
-extern const struct afb_binding_interface *binder_interface;
\ No newline at end of file
+extern const struct afb_binding_interface *binder_interface;
+
+void on_no_clients(std::string message);
\ No newline at end of file