refactor: extract should_retry

src/client/generic_http_consumer.ml

@@ -60,15 +60,33 @@ end = struct
 
     let cleanup self = Httpc.cleanup self.http
 
+    (** Should we retry, based on the HTTP response code? *)
+    let should_retry = function
+      | `Failure _ -> true (* Network errors, connection issues *)
+      | `Status (code, _) ->
+        (* Retry on server errors, rate limits, timeouts *)
+        code >= 500 || code = 429 || code = 408
+      | `Sysbreak -> false (* User interrupt, don't retry *)
+
+    (** Retry loop over [f()] with exponential backoff *)
+    let rec retry_loop_ (self : t) attempt delay_ms ~f =
+      let open IO in
+      let* result = f () in
+      match result with
+      | Ok x -> return (Ok x)
+      | Error err
+        when should_retry err && attempt < self.config.retry_max_attempts ->
+        let delay_s = delay_ms /. 1000. in
+        let* () = sleep_s delay_s in
+        let next_delay =
+          min self.config.retry_max_delay_ms
+            (delay_ms *. self.config.retry_backoff_multiplier)
+        in
+        retry_loop_ self (attempt + 1) next_delay ~f
+      | Error _ as err -> return err
+
     let send (self : t) (sigs : OTEL.Any_signal_l.t) : (unit, error) result IO.t
         =
-      let should_retry = function
-        | `Failure _ -> true (* Network errors, connection issues *)
-        | `Status (code, _) ->
-          (* Retry on server errors, rate limits, timeouts *)
-          code >= 500 || code = 429 || code = 408
-        | `Sysbreak -> false (* User interrupt, don't retry *)
-      in
       let res = Resource_signal.of_signal_l sigs in
       let url, signal_headers =
         match res with
@@ -98,30 +116,14 @@ end = struct
           ~protocol:self.config.protocol res
       in
 
-      (* Retry loop with exponential backoff *)
+      let do_once () =
-      let rec retry_send attempt delay_ms =
+        Httpc.send self.http ~url ~headers ~decode:(`Ret ()) data
-        let open IO in
-        let* result =
-          Httpc.send self.http ~url ~headers ~decode:(`Ret ()) data
-        in
-        match result with
-        | Ok x -> return (Ok x)
-        | Error err
-          when should_retry err && attempt < self.config.retry_max_attempts ->
-          let delay_s = delay_ms /. 1000. in
-          let* () = sleep_s delay_s in
-          let next_delay =
-            min self.config.retry_max_delay_ms
-              (delay_ms *. self.config.retry_backoff_multiplier)
-          in
-          retry_send (attempt + 1) next_delay
-        | Error _ as err -> return err
       in
 
       if self.config.retry_max_attempts > 0 then
-        retry_send 0 self.config.retry_initial_delay_ms
+        retry_loop_ self 0 self.config.retry_initial_delay_ms ~f:do_once
       else
-        Httpc.send self.http ~url ~headers ~decode:(`Ret ()) data
+        do_once ()
   end
 
   module C = Generic_consumer.Make (IO) (Notifier) (Sender)