registry: remove units sorting since we already reclaim sorted keys f…

…rom etcd

We are already reclaiming sorted Job units from etcd, so remove the
sorting logic and an extra loop while we are it.

registry/job.go

@@ -90,6 +90,7 @@ func (r *EtcdRegistry) Schedule() ([]job.ScheduledUnit, error) {
 func (r *EtcdRegistry) Units() ([]job.Unit, error) {
 	key := r.prefixed(jobPrefix)
 	opts := &etcd.GetOptions{
+		// We need Job Units to be sorted
 		Sort:      true,
 		Recursive: true,
 	}
@@ -117,8 +118,9 @@ func (r *EtcdRegistry) Units() ([]job.Unit, error) {
 		return unit
 	}
 
-	var sortable sort.StringSlice
-	uMap := make(map[string]*job.Unit)
+	// make it at least size of Nodes
+	uMap := make(map[string]bool, len(res.Node.Nodes))
+	units := make([]job.Unit, 0)
 	for _, dir := range res.Node.Nodes {
 		u, err := r.dirToUnit(dir, unitHashLookupFunc)
 		if err != nil {
@@ -134,15 +136,8 @@ func (r *EtcdRegistry) Units() ([]job.Unit, error) {
 			continue
 		}
 
-		uMap[u.Name] = u
-		sortable = append(sortable, u.Name)
-	}
-
-	sortable.Sort()
-
-	units := make([]job.Unit, len(sortable))
-	for i, name := range sortable {
-		units[i] = *uMap[name]
+		uMap[u.Name] = true
+		units = append(units, *u)
 	}
 
 	return units, nil