bslPingRegister.ml

(*
    Copyright © 2011 MLstate

    This file is part of OPA.

    OPA is free software: you can redistribute it and/or modify it under the
    terms of the GNU Affero General Public License, version 3, as published by
    the Free Software Foundation.

    OPA is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for
    more details.

    You should have received a copy of the GNU Affero General Public License
    along with OPA. If not, see <http://www.gnu.org/licenses/>.
*)
(** Communications with opa client *)

open Cps.Ops

module JS = JsonTypes

type json = JS.json

let serialize_uu, unserialize_uu, set_uu =
  let serialize = ref (fun (_ : unit -> unit) (_ : json -> unit) -> ((failwith "Unregistered serialization function") : unit)) in
  let unserialize = ref (fun (_ : json) (_ : (unit -> unit) -> unit) -> ((failwith "Unregistered unserialization function") : unit)) in
  (fun x -> !serialize x), (fun x -> !unserialize x),
  (fun s u -> serialize := s; unserialize := u)

(** Define an identifier for opa client and which message they can
    be receive from server (with PingRegister) *)
module Client : sig
  (** Type of a client connection identifier.  Current implementation
      it's an opa record that represents the thread context. *)
  type key

  (** Create a cid from cookie and page identifier. *)
  val key : string -> int -> key

  (** To string (for debug) *)
  val key_to_string : key -> string

  (** To record (for embedding in thread context)*)
  val key_to_record: key -> ServerLib.ty_record

  type msg =
    | SendCChan of (string * json)
    | SendCChanThen of (string * json * (unit -> unit) * (unit -> unit))
    | RPC of (string * string * json)
    | AsyncRPC of (string * json)

  val serialize : msg -> json Cps.t

end = struct

  (* It's the opa records that represents the thread context.
     see thread_context.opa *)
  type key = ServerLib.ty_record

  let fclient  = ServerLib.static_field_of_name "client"
  let fpage    = ServerLib.static_field_of_name "page"

  let key =
    fun cookie page ->
      try
        let rpage   = ServerLib.wrap_int page in
        let rclient = ServerLib.wrap_string cookie in
        let ctx =
          ServerLib.add_field
            (ServerLib.add_field ServerLib.empty_record_constructor
               (fpage) rpage)
            (fclient) rclient in
        ServerLib.make_record ctx
      with _ -> failwith ("Error on ket generation")

  let key_to_string t = Base.Obj.dump t
  let key_to_record x = x

  type msg =
    | SendCChan of (string * json)
    | SendCChanThen of (string * json * (unit -> unit) * (unit -> unit))
    | RPC of (string * string * json)
    | AsyncRPC of (string * json)

  let serialize json k =
    match json with
    | SendCChan (id, json) ->
        (JS.Record [("type", JS.String "chan");
                    ("id", JS.String id);
                    ("msg", json)]) |> k
    | SendCChanThen (id, json, herror, hsuccess) ->
        serialize_uu herror @>
          (function herror ->
             serialize_uu hsuccess @>
               function hsuccess ->
                 JS.Record [("type", JS.String "chan");
                            ("id", JS.String id);
                            ("msg", json);
                            ("herror", herror);
                            ("hsuccess", hsuccess);
                           ] |> k)
    | RPC (id, name, json) ->
        JS.Record [("type", JS.String "rpc");
                   ("id", JS.String id);
                   ("name", JS.String name);
                   ("args", json)] |> k
    | AsyncRPC (name, json) ->
        JS.Record [("type", JS.String "asyncrpc");
                   ("name", JS.String name);
                   ("args", json)] |> k

end

(** Scheduler module for ping register *)
module PingScheduler = struct
  include BslScheduler
  type async_key = Scheduler.async_key
  let sleep = asleep
end

(** Instantiated ping register with opa scheduler and op client *)
module M = PingRegister.Make(PingScheduler)(Client)

##register client_start : opa[ThreadContext.client] -> void
let client_start ck = M.create (Obj.magic ck)

##register nb_connection : -> int
let nb_connection = M.size

##register client_stop : opa[ThreadContext.client] -> void
let client_stop ck = M.delete (Obj.magic ck)