etcdserver: refactor a bit

etcdserver2/server.go

@@ -20,16 +20,9 @@ var (
 type SendFunc func(m []raftpb.Message)
 
 type Response struct {
-	// The last seen term raft was at when this request was built.
-	Term int64
-
-	// The last seen index raft was at when this request was built.
-	Commit int64
-
 	Event   *store.Event
 	Watcher *store.Watcher
-
-	err error
+	err     error
 }
 
 type Server struct {
@@ -73,12 +66,7 @@ func (s *Server) run() {
 				if err := r.Unmarshal(e.Data); err != nil {
 					panic("TODO: this is bad, what do we do about it?")
 				}
-
-				var resp Response
-				resp.Event, resp.err = s.apply(context.TODO(), r)
-				resp.Term = rd.Term
-				resp.Commit = rd.Commit
-				s.w.Trigger(r.Id, resp)
+				s.w.Trigger(r.Id, s.apply(r))
 			}
 		case <-s.done:
 			return
@@ -142,37 +130,40 @@ func (s *Server) Do(ctx context.Context, r pb.Request) (Response, error) {
 }
 
 // apply interprets r as a call to store.X and returns an Response interpreted from store.Event
-func (s *Server) apply(ctx context.Context, r pb.Request) (*store.Event, error) {
+func (s *Server) apply(r pb.Request) Response {
+	f := func(ev *store.Event, err error) Response {
+		return Response{Event: ev, err: err}
+	}
 	expr := time.Unix(0, r.Expiration)
 	switch r.Method {
 	case "POST":
-		return s.Store.Create(r.Path, r.Dir, r.Val, true, expr)
+		return f(s.Store.Create(r.Path, r.Dir, r.Val, true, expr))
 	case "PUT":
 		exists, existsSet := getBool(r.PrevExists)
 		switch {
 		case existsSet:
 			if exists {
-				return s.Store.Update(r.Path, r.Val, expr)
+				return f(s.Store.Update(r.Path, r.Val, expr))
 			} else {
-				return s.Store.Create(r.Path, r.Dir, r.Val, false, expr)
+				return f(s.Store.Create(r.Path, r.Dir, r.Val, false, expr))
 			}
 		case r.PrevIndex > 0 || r.PrevValue != "":
-			return s.Store.CompareAndSwap(r.Path, r.PrevValue, r.PrevIndex, r.Val, expr)
+			return f(s.Store.CompareAndSwap(r.Path, r.PrevValue, r.PrevIndex, r.Val, expr))
 		default:
-			return s.Store.Set(r.Path, r.Dir, r.Val, expr)
+			return f(s.Store.Set(r.Path, r.Dir, r.Val, expr))
 		}
 	case "DELETE":
 		switch {
 		case r.PrevIndex > 0 || r.PrevValue != "":
-			return s.Store.CompareAndDelete(r.Path, r.PrevValue, r.PrevIndex)
+			return f(s.Store.CompareAndDelete(r.Path, r.PrevValue, r.PrevIndex))
 		default:
-			return s.Store.Delete(r.Path, r.Recursive, r.Dir)
+			return f(s.Store.Delete(r.Path, r.Recursive, r.Dir))
 		}
 	case "QGET":
-		return s.Store.Get(r.Path, r.Recursive, r.Sorted)
+		return f(s.Store.Get(r.Path, r.Recursive, r.Sorted))
 	default:
 		// This should never be reached, but just in case:
-		return nil, ErrUnknownMethod
+		return Response{err: ErrUnknownMethod}
 	}
 }