add some example programs to exercize server-sent events

examples/dune

@@ -0,0 +1,10 @@
+
+(executable
+  (name sse_clock)
+  (modules sse_clock)
+  (libraries tiny_httpd unix ptime ptime.clock.os))
+
+(executable
+  (name sse_client)
+  (modules sse_client)
+  (libraries unix))

examples/sse_client.ml

@@ -0,0 +1,28 @@
+let addr = ref "127.0.0.1"
+let port = ref 8080
+
+let bufsize = 1024
+
+let () =
+  Arg.parse (Arg.align [
+      "-p", Arg.Set_int port, " port to connect to";
+    ]) (fun s -> addr := s) "sse_client [opt]* [addr]?";
+
+  Format.printf "connect to %s:%d@." !addr !port;
+  let sock = Unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
+  Unix.connect sock (Unix.ADDR_INET (Unix.inet_addr_of_string !addr, !port));
+  Unix.setsockopt sock Unix.TCP_NODELAY false;
+
+  let ic = Unix.in_channel_of_descr sock in
+  let oc = Unix.out_channel_of_descr sock in
+  output_string oc "GET /clock HTTP/1.1\r\nHost: localhost\r\n\r\n";
+  flush oc;
+
+  let continue = ref true in
+  let buf = Bytes.create bufsize in
+  while !continue do
+    let n = input ic buf 0 bufsize in
+    if n=0 then continue := false;
+    output stdout buf 0 n; flush stdout
+  done;
+  Format.printf "bye!@."

examples/sse_clock.ml

@@ -0,0 +1,36 @@
+
+(* serves a stream of clock events *)
+
+module S = Tiny_httpd
+
+let port = ref 8080
+
+let () =
+  Arg.parse (Arg.align [
+      "-p", Arg.Set_int port, " port to listen on";
+      "--debug", Arg.Bool S._enable_debug, " toggle debug";
+    ]) (fun _ -> ()) "sse_clock [opt*]";
+  let server = S.create ~port:!port () in
+
+  S.add_route_server_sent_handler server S.Route.(exact "clock" @/ return)
+    (fun _req (module EV : S.SERVER_SENT_GENERATOR) ->
+       S._debug (fun k->k"new connection");
+       let tick = ref true in
+       while true do
+         let now = Ptime_clock.now() in
+         S._debug (fun k->k"send clock ev %s" (Format.asprintf "%a" Ptime.pp now));
+         EV.send_event ~event:(if !tick then "tick" else "tock")
+           ~data:(Ptime.to_rfc3339 now) ();
+         tick := not !tick;
+
+         Unix.sleepf 1.0;
+       done;
+    );
+
+  Printf.printf "listening on http://localhost:%d/\n%!" (S.port server);
+  match S.run server with
+  | Ok () -> ()
+  | Error e ->
+    Printf.eprintf "error: %s\n%!" (Printexc.to_string e); exit 1
+
+