hphp/hack/src/server/serverDebug.ml

   1 (**
   2  * Copyright (c) 2015, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the MIT license found in the
   6  * LICENSE file in the "hack" directory of this source tree.
   7  *
   8  *)
   9
  10 open Core_kernel
  11 [@@@warning "-52"] (* we have no alternative but to depend on Sys_error strings *)
  12 let log genv msg_thunk =
  13   Option.iter genv.ServerEnv.debug_channels begin fun (_ic, oc) ->
  14     (* The input is read using input_line, hence we append a trailing
  15      * newline *)
  16     (* We use a thunk so that expensive computations don't slow down the
  17      * server when the debug listener isn't attached *)
  18     let msg = msg_thunk () in
  19     try
  20       Out_channel.output_string oc ((Hh_json.json_to_string msg) ^ "\n");
  21       Out_channel.flush oc;
  22     with Sys_error "Broken pipe" -> begin
  23       Hh_logger.log "Debug listener has gone away.";
  24       genv.ServerEnv.debug_channels <- None;
  25     end
  26   end
  27 [@@@warning "+52"] (* CARE! scope of suppression should be only 'log' *)
  28
  29 let info genv msg =
  30   let open Hh_json in
  31   let msg = JSON_Object [
  32       "type", JSON_String "info";
  33       "data", JSON_String msg;
  34   ] in
  35   log genv (fun () -> msg)
  36
  37 let say_hello genv = info genv "hello"