hop-2012/server/subscription.ml

99 lines
3.1 KiB
OCaml

(* Copyright 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>. *)
(* This file is part of Hop. *)
(* Hop is free software: you can redistribute it and/or modify it *)
(* under the terms of the GNU General Public License as published by the *)
(* Free Software Foundation, either version 3 of the License, or (at your *)
(* option) any later version. *)
(* Hop 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 *)
(* General Public License for more details. *)
(* You should have received a copy of the GNU General Public License *)
(* along with Hop. If not, see <http://www.gnu.org/licenses/>. *)
open Lwt
open Datastructures
type t = {
mutable live: bool;
uuid: Uuid.t;
filter: Sexp.t;
sink: Node.name;
name: Sexp.t
}
type creation_t =
| Old of t
| New of t
type set_t = {
mutable subscription_table: Uuid.t SexpMap.t;
mutable uuid_table: t StringMap.t
}
let new_set () = {
subscription_table = SexpMap.empty;
uuid_table = StringMap.empty
}
let count subs = SexpMap.cardinal subs.subscription_table
let key_from sink_str name filter = Sexp.Arr [Sexp.Str sink_str; name; filter]
let create source subs filter sink_str name reply_sink reply_name =
let key = key_from sink_str name filter in
try
let uuid = SexpMap.find key subs.subscription_table in
lwt () =
Node.post_ignore' reply_sink reply_name (Message.subscribe_ok (Sexp.Str uuid)) (Sexp.Str "")
in
return (Old (StringMap.find uuid subs.uuid_table))
with Not_found ->
let uuid = Uuid.create () in
let sink = Node.name_of_string sink_str in
let sub = {
live = true;
uuid = uuid;
filter = filter;
sink = sink;
name = name
} in
subs.uuid_table <- StringMap.add uuid sub subs.uuid_table;
subs.subscription_table <- SexpMap.add key uuid subs.subscription_table;
lwt () = Lwt.join [
Meta.announce_subscription source filter sink_str name true;
Node.post_ignore' reply_sink reply_name (Message.subscribe_ok (Sexp.Str uuid)) (Sexp.Str "")
] in
return (New sub)
let delete source subs uuid =
try
let sub = StringMap.find uuid subs.uuid_table in
sub.live <- false;
subs.uuid_table <- StringMap.remove uuid subs.uuid_table;
let key = key_from sub.sink.Node.label sub.name sub.filter in
subs.subscription_table <- SexpMap.remove key subs.subscription_table;
lwt () = Meta.announce_subscription source sub.filter sub.sink.Node.label sub.name false in
return (Some sub)
with Not_found ->
return None
let lookup subs uuid =
try Some (StringMap.find uuid subs.uuid_table)
with Not_found -> None
let send_to_subscription' sub body delete_action =
if not sub.live
then return false
else
match_lwt Node.post sub.sink sub.name body (Sexp.Str sub.uuid) with
| true -> return true
| false -> (lwt _ = delete_action sub.uuid in return false)
let send_to_subscription source subs sub body =
send_to_subscription' sub body (fun (uuid) -> delete source subs uuid)