veyron2/ipc: 2 of n. 'Invoker and Signature' rationalisation.
See https://veyron-review.googlesource.com/#/c/6254.
This adds Serve and ServeDispatcher, the only application
affected by this is wsprd.
Change-Id: Ic5dbcea9a0da5f840d61746955f3c553566e26f6
diff --git a/runtimes/google/ipc/server.go b/runtimes/google/ipc/server.go
index 8cfa9e9..115615f 100644
--- a/runtimes/google/ipc/server.go
+++ b/runtimes/google/ipc/server.go
@@ -533,7 +533,33 @@
}
}
-func (s *server) Serve(name string, disp ipc.Dispatcher) error {
+func (s *server) Serve(name string, obj interface{}) error {
+ if obj == nil {
+ // nil is an allowed value for obj.
+ return s.ServeDispatcher(name, ipc.Dispatcher(nil))
+ }
+ // TRANSITION: this will be disallowed when the transition is complete.
+ if disp, ok := obj.(ipc.Dispatcher); ok {
+ return s.ServeDispatcher(name, disp)
+ }
+ // TRANSITION: We may fail the dispatcher type test, but still be a
+ // dispatcher becase our Lookup method returns ipc.Invoker and not a
+ // raw object. This code here will detect that case and panic as an aid
+ // to catching these cases early.
+ typ := reflect.TypeOf(obj)
+ if lookup, found := typ.MethodByName("Lookup"); found {
+ if lookup.Type.NumIn() == 3 && lookup.Type.NumOut() == 3 {
+ inv := lookup.Type.Out(0)
+ if inv.Name() == "Invoker" {
+ panic(fmt.Sprintf("%q has a Lookup that returns an Invoker", lookup.Name))
+ }
+ }
+ }
+ // TRANSITION: this will go away in the transition.
+ panic("should never get here")
+}
+
+func (s *server) ServeDispatcher(name string, disp ipc.Dispatcher) error {
defer vlog.LogCall()()
s.Lock()
defer s.Unlock()
@@ -746,6 +772,20 @@
return &req, nil
}
+func lookupInvoker(d ipc.Dispatcher, name, method string) (ipc.Invoker, security.Authorizer, error) {
+ obj, auth, err := d.Lookup(name, method)
+ switch {
+ case err != nil:
+ return nil, nil, err
+ case obj == nil:
+ return nil, auth, nil
+ }
+ if invoker, ok := obj.(ipc.Invoker); ok {
+ return invoker, auth, nil
+ }
+ return ipc.ReflectInvoker(obj), auth, nil
+}
+
func (fs *flowServer) processRequest() ([]interface{}, verror.E) {
start := time.Now()
@@ -809,17 +849,11 @@
fs.discharges[d.ID()] = d
}
// Lookup the invoker.
- obj, auth, suffix, verr := fs.lookup(req.Suffix, req.Method)
+ invoker, auth, suffix, verr := fs.lookup(req.Suffix, req.Method)
fs.suffix = suffix // with leading /'s stripped
if verr != nil {
return nil, verr
}
- // TODO(cnicolaou): ipc.Serve TRANSITION
- invoker, ok := obj.(ipc.Invoker)
- if !ok {
- panic("Lookup should have returned an ipc.Invoker")
- }
-
// Prepare invoker and decode args.
numArgs := int(req.NumPosArgs)
argptrs, label, err := invoker.Prepare(req.Method, numArgs)
@@ -858,7 +892,7 @@
// invoker. Otherwise, and we use the server's dispatcher. The (stripped) name
// and dispatch suffix are also returned.
// TODO(cnicolaou): change this back returning in ipc.Invoker in the pt2 CL.
-func (fs *flowServer) lookup(name, method string) (interface{}, security.Authorizer, string, verror.E) {
+func (fs *flowServer) lookup(name, method string) (ipc.Invoker, security.Authorizer, string, verror.E) {
name = strings.TrimLeft(name, "/")
if method == "Glob" && len(name) == 0 {
return ipc.ReflectInvoker(&globInvoker{fs.reservedOpt.Prefix, fs}), &acceptAllAuthorizer{}, name, nil
@@ -872,7 +906,7 @@
}
if disp != nil {
- invoker, auth, err := disp.Lookup(name, method)
+ invoker, auth, err := lookupInvoker(disp, name, method)
switch {
case err != nil:
return nil, nil, "", verror.Convert(err)
