wip

pkg/actor/mutation_registry.go

@@ -41,14 +41,16 @@ type MutationRegistry interface {
 	Create(typeName string) (proto.Message, bool)
 	GetTypeName(msg proto.Message) (string, bool)
 	RegisterProcessor(processor ...MutationProcessor)
-	//GetStorageEvent(msg proto.Message) StorageEvent
-	//FromStorageEvent(event StorageEvent) (proto.Message, error)
+	RegisterTrigger(trigger ...TriggerHandler)
+	SetEventChannel(ch chan<- ApplyResult)
 }
 
 type ProtoMutationRegistry struct {
 	mutationRegistryMu sync.RWMutex
 	mutationRegistry   map[reflect.Type]MutationHandler
+	triggers           map[reflect.Type][]TriggerHandler
 	processors         []MutationProcessor
+	eventChannel       chan<- ApplyResult
 }
 
 var (
@@ -84,6 +86,26 @@ func WithTotals() MutationOption {
 	}
 }
 
+type TriggerHandler interface {
+	Handle(state any, msg proto.Message) []proto.Message
+	Name() string
+	Type() reflect.Type
+}
+
+type RegisteredTrigger[V any, I proto.Message] struct {
+	name    string
+	handler func(state any, msg proto.Message) []proto.Message
+	msgType reflect.Type
+}
+
+func NewTrigger[V any, I proto.Message](name string, handler func(state any, msg proto.Message) []proto.Message) *RegisteredTrigger[V, I] {
+	return &RegisteredTrigger[V, I]{
+		name:    name,
+		handler: handler,
+		msgType: reflect.TypeOf((*I)(nil)).Elem(),
+	}
+}
+
 type MutationHandler interface {
 	Handle(state any, msg proto.Message) error
 	Name() string
@@ -145,6 +167,7 @@ func NewMutationRegistry() MutationRegistry {
 	return &ProtoMutationRegistry{
 		mutationRegistry:   make(map[reflect.Type]MutationHandler),
 		mutationRegistryMu: sync.RWMutex{},
+		triggers:           make(map[reflect.Type][]TriggerHandler),
 		processors:         make([]MutationProcessor, 0),
 	}
 }
@@ -162,6 +185,24 @@ func (r *ProtoMutationRegistry) RegisterMutations(handlers ...MutationHandler) {
 	}
 }
 
+func (r *ProtoMutationRegistry) RegisterTrigger(triggers ...TriggerHandler) {
+	r.mutationRegistryMu.Lock()
+	defer r.mutationRegistryMu.Unlock()
+
+	for _, trigger := range triggers {
+		existingTriggers, ok := r.triggers[trigger.Type()]
+		if !ok {
+			r.triggers[trigger.Type()] = []TriggerHandler{trigger}
+		} else {
+			r.triggers[trigger.Type()] = append(existingTriggers, trigger)
+		}
+	}
+}
+
+func (r *ProtoMutationRegistry) SetEventChannel(ch chan<- ApplyResult) {
+	r.eventChannel = ch
+}
+
 func (r *ProtoMutationRegistry) GetTypeName(msg proto.Message) (string, bool) {
 	r.mutationRegistryMu.RLock()
 	defer r.mutationRegistryMu.RUnlock()
@@ -244,6 +285,25 @@ func (r *ProtoMutationRegistry) Apply(ctx context.Context, grain any, msg ...pro
 			if err != nil {
 				msgSpan.RecordError(err)
 			}
+			if r.eventChannel != nil {
+				go func() {
+					defer func() {
+						if r := recover(); r != nil {
+							// Handle panic from sending to closed channel
+							log.Printf("event channel closed: %v", r)
+						}
+					}()
+					for _, tr := range r.triggers[rt] {
+						for _, msg := range tr.Handle(grain, m) {
+							select {
+							case r.eventChannel <- msg:
+							default:
+								// Channel full or no receiver, skip to avoid blocking
+							}
+						}
+					}
+				}()
+			}
 			results = append(results, ApplyResult{Error: err, Type: rt.Name(), Mutation: m})
 		}
 		msgSpan.End()
@@ -266,6 +326,7 @@ func (r *ProtoMutationRegistry) Apply(ctx context.Context, grain any, msg ...pro
 			return results, res.Error
 		}
 	}
+
 	return results, nil
 }