lpp: add Heartbeat event

with this, application is able to validate heartbeat data and can implement a watchdog for failsafe watching

uclppserver/api.go

@@ -76,6 +76,9 @@ type UCLPPServerInterface interface {
 	// Scenario 3
 
 	// this is automatically covered by the SPINE implementation
+	//
+	// returns true, if the last heartbeat is within 2 minutes, otherwise false
+	IsHeartbeatWithinDuration() bool
 
 	// Scenario 4
 

uclppserver/events.go

@@ -33,6 +33,10 @@ func (e *UCLPPServer) HandleEvent(payload spineapi.EventPayload) {
 		return
 	}
 
+	if util.IsHeartbeat(localEntity, payload) {
+		e.eventCB(payload.Ski, payload.Device, payload.Entity, Heartbeat)
+	}
+
 	if localEntity == nil ||
 		payload.EventType != spineapi.EventTypeDataChange ||
 		payload.ChangeType != spineapi.ElementChangeUpdate ||
@@ -98,6 +102,7 @@ func (e *UCLPPServer) deviceConnected(payload spineapi.EventPayload) {
 	// we only found one matching entity, as it should be, subscribe
 	if len(deviceDiagEntites) == 1 {
 		if localDeviceDiag, err := util.DeviceDiagnosis(e.service, deviceDiagEntites[0]); err == nil {
+			e.heartbeatDiag = localDeviceDiag
 			if _, err := localDeviceDiag.Subscribe(); err != nil {
 				logging.Log().Debug(err)
 			}
@@ -124,6 +129,7 @@ func (e *UCLPPServer) subscribeHeartbeatWorkaround(payload spineapi.EventPayload
 	}
 
 	if localDeviceDiag, err := util.DeviceDiagnosis(e.service, payload.Entity); err == nil {
+		e.heartbeatDiag = localDeviceDiag
 		if _, err := localDeviceDiag.Subscribe(); err != nil {
 			logging.Log().Debug(err)
 		}

uclppserver/public.go

@@ -237,6 +237,12 @@ func (e *UCLPPServer) SetFailsafeDurationMinimum(duration time.Duration, changea
 	return util.SetLocalDeviceConfigurationKeyValue(e.service, keyName, changeable, keyValue)
 }
 
+// Scenario 3
+
+func (e *UCLPPServer) IsHeartbeatWithinDuration() bool {
+	return e.heartbeatDiag.IsHeartbeatWithinDuration(2 * time.Minute)
+}
+
 // Scenario 4
 
 // return nominal maximum active (real) power the Controllable System is

uclppserver/types.go

@@ -33,4 +33,9 @@ const (
 	//
 	// Use Case LPC, Scenario 2
 	DataUpdateFailsafeDurationMinimum api.EventType = "DataUpdateFailsafeDurationMinimum"
+
+	// Indicates a notify heartbeat event the application should care of.
+	// E.g. going into or out of the Failsafe state
+	// Use Case LPP, Scenario 3
+	Heartbeat api.EventType = "Heartbeat"
 )

uclppserver/uclpp.go

@@ -7,6 +7,7 @@ import (
 	"github.com/enbility/cemd/api"
 	"github.com/enbility/cemd/util"
 	eebusapi "github.com/enbility/eebus-go/api"
+	"github.com/enbility/eebus-go/features"
 	eebusutil "github.com/enbility/eebus-go/util"
 	spineapi "github.com/enbility/spine-go/api"
 	"github.com/enbility/spine-go/model"
@@ -23,6 +24,8 @@ type UCLPPServer struct {
 	pendingMux    sync.Mutex
 	pendingLimits map[model.MsgCounterType]*spineapi.Message
 
+	heartbeatDiag *features.DeviceDiagnosis
+
 	heartbeatKeoWorkaround bool // required because KEO Stack uses multiple identical entities for the same functionality, and it is not clear which to use
 }