process: read a state its owner keeps one bucket per node as one state, so the provisioner, the assigner and the view read every node's compositions (ADR 0593 §6)

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

go/process/state.go

@@ -28,6 +28,8 @@ const stateTimeout = 30 * time.Second
 type State struct {
 	Module string
 	Name   string
+	// bucketName is the bucket when it is not <module>_<name>: one node's bucket of a per-node state (NodeFamily).
+	bucketName string
 	// kv binds this state's underlying key-value store: a live connection's own (Conn.State), or, in a
 	// unit test, a fake that never reaches a bus.
 	kv func(ctx context.Context) (jetstream.KeyValue, error)
@@ -36,14 +38,19 @@ type State struct {
 }
 
 // bucket is this state's name on the bus.
-func (s State) bucket() string { return s.Module + "_" + s.Name }
+func (s State) bucket() string {
+	if s.bucketName != "" {
+		return s.bucketName
+	}
+	return s.Module + "_" + s.Name
+}
 
 // State is the named state this connection's module keeps, bound lazily to its bucket on each call so a
 // bucket the account is not granted fails at the call that needed it, naming the bucket. The bind itself
 // (js.KeyValue) is what asks $JS.API.STREAM.INFO.KV_<bucket>, so it is what withRefusal watches: a bucket
 // not granted is refused there, promptly, as nats.ErrPermissionViolation.
 func (c *Conn) State(name string) State {
-	return c.bound(c.account.Module, name, func() error { return c.refusedUnannounced(name) })
+	return c.bound(c.account.Module, name, "", func() error { return c.refusedUnannounced(name) })
 }
 
 // Read is another module's state this connection's module reads, named as its manifest's `reads` names it
@@ -52,7 +59,7 @@ func (c *Conn) State(name string) State {
 // the seat mesh-provisioner's plans). A name that is not `<module>.<state>` fails at the call that needed it.
 func (c *Conn) Read(read string) State {
 	module, name, ok := strings.Cut(read, ".")
-	return c.bound(module, name, func() error {
+	return c.bound(module, name, "", func() error {
 		if !ok || module == "" || name == "" || strings.Contains(name, ".") {
 			return fmt.Errorf("%q is not a state another module keeps, <module>.<state>", read)
 		}
@@ -60,10 +67,14 @@ func (c *Conn) Read(read string) State {
 	})
 }
 
-// bound is module's state name on this connection, checked by refused before every bind.
-func (c *Conn) bound(module, name string, refused func() error) State {
-	bucket := module + "_" + name
-	return State{Module: module, Name: name, closed: func() bool { return c.nc.IsClosed() }, kv: func(ctx context.Context) (jetstream.KeyValue, error) {
+// bound is module's state name on this connection, in its bucket <module>_<name> or the bucket given, checked by
+// refused before every bind.
+func (c *Conn) bound(module, name, bucket string, refused func() error) State {
+	given := bucket
+	if bucket == "" {
+		bucket = module + "_" + name
+	}
+	return State{Module: module, Name: name, bucketName: given, closed: func() bool { return c.nc.IsClosed() }, kv: func(ctx context.Context) (jetstream.KeyValue, error) {
 		if err := refused(); err != nil {
 			return nil, err
 		}