CP-54828: avoid raising exceptions all the time in the RBAC code

We can use Hashtbl.mem instead of catching the exception from Hashtbl.find.

Signed-off-by: Edwin Török <edwin.torok@cloud.com>

Author: edwintorok

ocaml/xapi/xapi_local_session.ml

@@ -31,12 +31,9 @@ let create ~__context ~pool =
   with_lock m (fun () -> Hashtbl.replace table r session) ;
   r
 
-let get_record ~__context ~self = with_lock m (fun () -> Hashtbl.find table self)
+let has_record ~__context ~self = with_lock m (fun () -> Hashtbl.mem table self)
 
 let destroy ~__context ~self = with_lock m (fun () -> Hashtbl.remove table self)
 
 let local_session_hook ~__context ~session_id =
-  try
-    ignore (get_record ~__context ~self:session_id) ;
-    true
-  with _ -> false
+  has_record ~__context ~self:session_id

ocaml/xapi/xapi_local_session.mli

@@ -19,8 +19,6 @@ val get_all : __context:Context.t -> API.ref_session list
 
 val create : __context:Context.t -> pool:bool -> API.ref_session
 
-val get_record : __context:Context.t -> self:API.ref_session -> t
-
 val destroy : __context:Context.t -> self:API.ref_session -> unit
 
 val local_session_hook :

quality-gate.sh

@@ -110,7 +110,7 @@ unixgetenv () {
 }
 
 hashtblfind () {
-  N=35
+  N=34
   # Looks for all .ml files except the ones using Core.Hashtbl.find,
   # which already returns Option
   HASHTBLFIND=$(git grep -P -r --count 'Hashtbl.find(?!_opt)' -- '**/*.ml' ':!ocaml/xapi-storage-script/main.ml' | cut -d ':' -f 2 | paste -sd+ - | bc)