example of echo server over websockets

examples/dune

@@ -20,6 +20,12 @@
  (modules writer)
  (libraries tiny_httpd logs))
 
+(executable
+ (name echo_ws)
+ (flags :standard -warn-error -a+8)
+ (modules echo_ws)
+ (libraries tiny_httpd tiny_httpd_ws logs))
+
 (rule
  (targets test_output.txt)
  (deps

examples/echo_ws.ml

@@ -0,0 +1,51 @@
+module S = Tiny_httpd
+module Log = Tiny_httpd.Log
+module IO = Tiny_httpd_io
+
+let setup_logging ~debug () =
+  Logs.set_reporter @@ Logs.format_reporter ();
+  Logs.set_level ~all:true
+  @@ Some
+       (if debug then
+         Logs.Debug
+       else
+         Logs.Info)
+
+let () =
+  let port_ = ref 8080 in
+  let j = ref 32 in
+  let debug = ref false in
+  Arg.parse
+    (Arg.align
+       [
+         "--port", Arg.Set_int port_, " set port";
+         "-p", Arg.Set_int port_, " set port";
+         "--debug", Arg.Set debug, " enable debug";
+         "-j", Arg.Set_int j, " maximum number of connections";
+       ])
+    (fun _ -> raise (Arg.Bad ""))
+    "echo [option]*";
+  setup_logging ~debug:!debug ();
+
+  let server = S.create ~port:!port_ ~max_connections:!j () in
+  Tiny_httpd_ws.add_route_handler server
+    S.Route.(exact "echo" @/ return)
+    (fun ic oc ->
+      Log.info (fun k -> k "new client connection");
+      let buf = Bytes.create 32 in
+      let continue = ref true in
+      while !continue do
+        let n = IO.Input.input ic buf 0 (Bytes.length buf) in
+        Log.debug (fun k ->
+            k "echo %d bytes from websocket: %s" n (Bytes.sub_string buf 0 n));
+
+        if n = 0 then continue := false;
+        IO.Output.output oc buf 0 n;
+        IO.Output.flush oc
+      done;
+      Log.info (fun k -> k "client exiting"));
+
+  Printf.printf "listening on http://%s:%d\n%!" (S.addr server) (S.port server);
+  match S.run server with
+  | Ok () -> ()
+  | Error e -> raise e