hphp/hack/src/monitor/informant_sig.ml

   1 (*
   2  * Copyright (c) 2016, 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 type report =
  11   (* Nothing to see here. *)
  12   | Move_along
  13   (* Kill the server (if one is running) and start a new one. *)
  14   | Restart_server of ServerMonitorUtils.target_saved_state option
  15
  16 type server_state =
  17   | Server_not_yet_started
  18   | Server_alive
  19   | Server_dead
  20
  21 (** The informant collects information to tell the monitor when to
  22  * intelligently kill and restart the server daemon.
  23  *
  24  * For example: An informant may want to watch the repo state and tell
  25  * the monitor to restart the server when a significant change in
  26  * repo revision occurs since a fresh initialization could be faster
  27  * than an incremental type check. *)
  28 module type S = sig
  29   type t
  30
  31   type init_env
  32
  33   val init : init_env -> t
  34
  35   (* Same as init, except it preserves internal Revision_map cache.
  36    * This is used when server decides to restart itself due to rebase - we don't
  37    * want Informant to then restart the server again. Reinitializing will discard
  38    * the pending queue of state changes, and issue new query for base revision,
  39    * in order to "synchronize" base revision understanding between server and
  40    * monitor. *)
  41   val reinit : t -> unit
  42
  43   val report : t -> server_state -> report
  44
  45   (*
  46    * Returns true if the informant is actually running and will
  47    * manage server lifetime.
  48    *)
  49   val is_managing : t -> bool
  50
  51   val should_start_first_server : t -> bool
  52
  53   val should_ignore_hh_version : init_env -> bool
  54 end