Add support for database subscription to layered profile provider

profile/profile-layered-provider.go

@@ -14,16 +14,24 @@ const (
 )
 
 var (
-	errProfileNotActive = errors.New("profile not active")
+	errProfileNotActive                  = errors.New("profile not active")
-	errNoLayeredProfile = errors.New("profile has no layered profile")
+	errNoLayeredProfile                  = errors.New("profile has no layered profile")
+	pushLayeredProfile  runtime.PushFunc = func(...record.Record) {}
 )
 
 func registerRevisionProvider() error {
-	_, err := runtime.Register(
+	push, err := runtime.Register(
 		revisionProviderPrefix,
 		runtime.SimpleValueGetterFunc(getRevisions),
 	)
-	return err
+
+	if err != nil {
+		return err
+	}
+
+	pushLayeredProfile = push
+
+	return nil
 }
 
 func getRevisions(key string) ([]record.Record, error) {

profile/profile-layered.go

@@ -127,6 +127,12 @@ func NewLayeredProfile(localProfile *Profile) *LayeredProfile {
 	new.CreateMeta()
 	new.SetKey(runtime.DefaultRegistry.DatabaseName() + ":" + revisionProviderPrefix + localProfile.ID)
 
+	// Inform database subscribers about the new layered profile.
+	new.Lock()
+	defer new.Unlock()
+
+	pushLayeredProfile(new)
+
 	return new
 }
 
@@ -231,6 +237,8 @@ func (lp *LayeredProfile) Update() (revisionCounter uint64) {
 
 		// bump revision counter
 		lp.RevisionCounter++
+
+		pushLayeredProfile(lp)
 	}
 
 	return lp.RevisionCounter