42 lines
1.2 KiB
OCaml
42 lines
1.2 KiB
OCaml
open Lwt.Infix
|
|
|
|
let create ~f =
|
|
let data : (string, int) Hashtbl.t = Hashtbl.create 7 in
|
|
(fun x ->
|
|
let key = f x in
|
|
let cur = match Hashtbl.find_opt data key with
|
|
| None -> 0
|
|
| Some x -> x
|
|
in
|
|
Hashtbl.replace data key (succ cur)),
|
|
(fun () ->
|
|
let data, total =
|
|
Hashtbl.fold (fun key value (acc, total) ->
|
|
(Metrics.uint key value :: acc), value + total)
|
|
data ([], 0)
|
|
in
|
|
Metrics.uint "total" total :: data)
|
|
|
|
let counter_metrics ~f name =
|
|
let open Metrics in
|
|
let doc = "Counter metrics" in
|
|
let incr, get = create ~f in
|
|
let data thing = incr thing; Data.v (get ()) in
|
|
Src.v ~doc ~tags:Metrics.Tags.[] ~data name
|
|
|
|
let add_http_status =
|
|
let f = function
|
|
| #Dream.informational -> "1xx"
|
|
| #Dream.successful -> "2xx"
|
|
| #Dream.redirection -> "3xx"
|
|
| #Dream.client_error -> "4xx"
|
|
| #Dream.server_error -> "5xx"
|
|
| `Status c -> Printf.sprintf "%dxx" (c / 100)
|
|
in
|
|
let src = counter_metrics ~f "http_response" in
|
|
(fun r -> Metrics.add src (fun x -> x) (fun d -> d r))
|
|
|
|
let handle next_handler req =
|
|
next_handler req >|= fun response ->
|
|
add_http_status (Dream.status response);
|
|
response
|