cohttp-eio: Debug body encoding.

cohttp-eio/src/server.ml

@@ -79,7 +79,11 @@ let write output response body =
   let () =
     Io.Response.write
       (fun writer ->
-        let () = Logs.debug (fun m -> m "send body") in
+        let () =
+          Logs.debug (fun m ->
+              (m "send body (%a)" Cohttp.Transfer.pp_encoding response.encoding
+               [@ocaml.warning "-3"]))
+        in
         flow_to_writer body writer Io.Response.write_body)
       response output
   in

cohttp/src/transfer.ml

@@ -19,6 +19,11 @@ open Sexplib0.Sexp_conv
 type encoding = Http.Transfer.encoding = Chunked | Fixed of int64 | Unknown
 [@@deriving sexp]
 
+let pp_encoding fmt = function
+  | Chunked -> Format.pp_print_string fmt "chunked"
+  | Fixed size -> Format.fprintf fmt "fixed %Ld" size
+  | Unknown -> Format.pp_print_string fmt "unknown"
+
 type chunk = Chunk of string | Final_chunk of string | Done [@@deriving sexp]
 
 let string_of_encoding = function

cohttp/src/transfer.mli

@@ -25,6 +25,9 @@ type encoding = Http.Transfer.encoding =
   | Unknown  (** unknown body size, which leads to best-effort *)
 [@@deriving sexp]
 
+val pp_encoding : Format.formatter -> encoding -> unit
+(** Human-readable output. *)
+
 (** A chunk of body that also signals if there to more to arrive *)
 type chunk =
   | Chunk of string  (** chunk of data and not the end of stream *)