stunnel_cache: remove ad-hoc chop implementation

This can be replaced with a List.drop. For now this is available in
xapi's stdext, but it will become part of the standard library

Signed-off-by: Pau Ruiz Safont <pau.safont@vates.tech>

Author: psafont

dune-project

@@ -612,6 +612,8 @@
    (= :version))
   (xapi-stdext-pervasives
    (= :version))
+  (xapi-stdext-std
+   (= :version))
   (xapi-stdext-threads
    (= :version))
   (xapi-stdext-unix

ocaml/libs/stunnel/dune

@@ -13,6 +13,7 @@
     xapi-inventory
     xapi-log
     xapi-stdext-pervasives
+    xapi-stdext-std
     xapi-stdext-threads
     xapi-stdext-unix
   )

ocaml/libs/stunnel/stunnel_cache.ml

@@ -27,6 +27,8 @@ open Safe_resources
 
 let with_lock = Xapi_stdext_threads.Threadext.Mutex.execute
 
+let list_drop = Xapi_stdext_std.Listext.List.drop
+
 (* Disable debug-level logging but leave higher-priority enabled.  It would be
  * better to handle this sort of configuration in the Debug module itself.
  *)
@@ -93,17 +95,6 @@ let unlocked_gc () =
            !index ""
         )
   ) ;
-  (* Split a list at the given index to give a pair of lists.
-   *  From Xapi_stdext_std.Listext *)
-  let rec chop i l =
-    match (i, l) with
-    | 0, l ->
-        ([], l)
-    | i, h :: t ->
-        (fun (fr, ba) -> (h :: fr, ba)) (chop (i - 1) t)
-    | _ ->
-        invalid_arg "chop"
-  in
   let all_ids = Tbl.fold !stunnels (fun k _ acc -> k :: acc) [] in
   let to_gc = ref [] in
   (* Find the ones which are too old *)
@@ -134,8 +125,8 @@ let unlocked_gc () =
       List.filter (fun (idx, _) -> not (List.mem idx !to_gc)) times'
     in
     (* Sort into descending order of donation time, ie youngest first *)
-    let times' = List.sort (fun x y -> compare (fst y) (fst x)) times' in
-    let _youngest, oldest = chop max_stunnel times' in
+    let times' = List.sort (fun (x, _) (y, _) -> compare y x) times' in
+    let oldest = list_drop max_stunnel times' in
     let oldest_ids = List.map fst oldest in
     List.iter
       (fun x ->

opam/stunnel.opam

@@ -18,6 +18,7 @@ depends: [
   "xapi-inventory"
   "xapi-log" {= version}
   "xapi-stdext-pervasives" {= version}
+  "xapi-stdext-std" {= version}
   "xapi-stdext-threads" {= version}
   "xapi-stdext-unix" {= version}
   "odoc" {with-doc}