mte/unikernel/duniverse/mimic/lib/mimic.ml
2025-11-11 02:07:51 +01:00

440 lines
13 KiB
OCaml

type 'a info = { name : string; root : root }
and root = Root of int option | Value
let pp_info ppf { name; root } =
match root with
| Root (Some p) -> Format.fprintf ppf "<%s:%d>" name p
| Root None -> Format.fprintf ppf "<%s>" name
| Value -> Format.fprintf ppf "%s" name
module Mirage_protocol = Mirage_protocol
module Info = struct type 'a t = 'a info end
module Hmap0 = Hmap.Make (Info)
let pp_value ppf value = Format.fprintf ppf "%a" pp_info (Hmap0.Key.info value)
let src = Logs.Src.create "mimic" ~doc:"logs mimic's event"
module Log = (val Logs.src_log src : Logs.LOG)
module rec Fun : sig
type ('k, 'res) args =
| [] : ('res, 'res) args
| ( :: ) : 'a arg * ('k, 'res) args -> ('a -> 'k, 'res) args
and 'v arg =
| Map : ('f, 'a) args * 'f -> 'a arg
| Req : 'a Hmap0.key -> 'a arg
| Opt : 'a Hmap0.key -> 'a option arg
| Dft : 'a * 'a Hmap0.key -> 'a arg
val req : 'a Hmap0.key -> 'a arg
val opt : 'a Hmap0.key -> 'a option arg
val dft : 'a Hmap0.key -> 'a -> 'a arg
val map : ('k, 'a) args -> 'k -> 'a arg
end = struct
type ('k, 'res) args =
| [] : ('res, 'res) args
| ( :: ) : 'a arg * ('k, 'res) args -> ('a -> 'k, 'res) args
and 'v arg =
| Map : ('f, 'a) args * 'f -> 'a arg
| Req : 'a Hmap0.key -> 'a arg
| Opt : 'a Hmap0.key -> 'a option arg
| Dft : 'a * 'a Hmap0.key -> 'a arg
let req value = Req value
let opt value = Opt value
let dft value v = Dft (v, value)
let map args k = Map (args, k)
end
and Value : sig
type 'a elt =
| Val : 'a -> 'a elt
| Fun : ('k, 'a option Lwt.t) Fun.args * 'k -> 'a elt
type 'a t = 'a elt list
end = struct
type 'a elt =
| Val : 'a -> 'a elt
| Fun : ('k, 'a option Lwt.t) Fun.args * 'k -> 'a elt
type 'a t = 'a elt list
end
module Hmap = Hmap0.Make (Value)
type ctx = Hmap.t
type 'edn value = 'edn Hmap0.key
let merge ctx0 ctx1 =
let f :
type a.
a value -> a Value.t option -> a Value.t option -> a Value.t option =
fun _k lst0 lst1 ->
match lst0, lst1 with
| Some lst0, Some lst1 -> Some (lst0 @ lst1)
| Some x, None | None, Some x -> Some x
| None, None -> None
in
Hmap.merge { f } ctx0 ctx1
module Merge (A : sig
val ctx : ctx
end) (B : sig
val ctx : ctx
end) =
struct
let ctx = merge A.ctx B.ctx
end
let add value v ctx =
match Hmap.find value ctx with
| Some lst -> Hmap.add value (lst @ [ Val v ]) ctx
| None -> Hmap.add value [ Val v ] ctx
let fold value args ~k ctx =
match Hmap.find value ctx with
| Some lst -> Hmap.add value (lst @ [ Fun (args, k) ]) ctx
| None -> Hmap.add value [ Fun (args, k) ] ctx
let replace value v ctx =
match Hmap.find value ctx with
| None -> Hmap.add value [ Val v ] ctx
| Some lst ->
let lst =
List.fold_left
(fun acc -> function
| Value.Fun _ as v -> v :: acc
| Value.Val _ -> acc)
[] lst
in
let lst = List.rev lst in
(* XXX(dinosaure): keep the order! *)
Hmap.add value (Val v :: lst) ctx
(***** Mirage_flow.S part *****)
module Implicit0 = Implicit.Make (struct
type 'flow t = (module Mirage_flow.S with type flow = 'flow)
end)
type flow = Implicit0.t = private ..
type error = [ `Msg of string | `Not_found | `Cycle ]
type write_error = [ `Msg of string | `Closed ]
let pp_error ppf = function
| `Msg err -> Format.pp_print_string ppf err
| `Not_found -> Format.pp_print_string ppf "No connection found"
| `Cycle -> Format.pp_print_string ppf "Context contains a cycle"
let pp_write_error ppf = function
| `Msg err -> Format.pp_print_string ppf err
| `Closed -> Format.pp_print_string ppf "Connection closed by peer"
let to_to_string pp v = Format.asprintf "%a" pp v
let read flow =
let (Implicit0.Value (flow, (module Flow))) = Implicit0.prj flow in
let open Lwt.Infix in
Flow.read flow
>|= Result.map_error (fun fe -> `Msg (to_to_string Flow.pp_error fe))
let write flow cs =
let (Implicit0.Value (flow, (module Flow))) = Implicit0.prj flow in
let open Lwt.Infix in
Flow.write flow cs >|= function
| Error `Closed -> Error `Closed
| Error e -> Error (`Msg (to_to_string Flow.pp_write_error e))
| Ok _ as v -> v
let writev flow css =
let (Implicit0.Value (flow, (module Flow))) = Implicit0.prj flow in
let open Lwt.Infix in
Flow.writev flow css
>|= Result.map_error (fun fe -> `Msg (to_to_string Flow.pp_write_error fe))
let shutdown flow mode =
let (Implicit0.Value (flow, (module Flow))) = Implicit0.prj flow in
Flow.shutdown flow mode
let close flow =
let (Implicit0.Value (flow, (module Flow))) = Implicit0.prj flow in
Flow.close flow
(***** Protocol (Mirage_flow.S + connect) part *****)
type ('edn, 'flow) snd = Snd : 'flow -> ('edn, 'flow) snd [@@warning "-37"]
type _ pack =
| Protocol :
'edn Hmap0.key
* 'flow Implicit0.witness
* (module Mirage_protocol.S
with type flow = 'flow
and type endpoint = 'edn)
-> ('edn, 'flow) snd pack
module Implicit1 = Implicit.Make (struct type 'v t = 'v pack end)
type ('edn, 'flow) protocol = {
flow : 'flow Implicit0.witness;
protocol : ('edn, 'flow) snd Implicit1.witness;
}
let register :
type edn flow.
?priority:int ->
name:string ->
(module Mirage_protocol.S with type flow = flow and type endpoint = edn) ->
edn value * (edn, flow) protocol =
fun ?priority ~name (module Protocol) ->
let value = Hmap0.Key.create { name; root = Root priority } in
let flow = Implicit0.inj (module Protocol) in
let protocol = Implicit1.inj (Protocol (value, flow, (module Protocol))) in
value, { flow; protocol }
module type REPR = sig
type t type flow += (* XXX(dinosaure): private? *) T of t
end
let repr :
type edn flow. (edn, flow) protocol -> (module REPR with type t = flow) =
fun { flow; _ } ->
let (module Witness) = flow in
let module M = struct
include Witness
type t = a
end in
(module M)
let rec apply :
type k res. ctx -> (k, res option Lwt.t) Fun.args -> k -> res option Lwt.t =
fun ctx args f ->
let open Lwt.Infix in
let rec go : type k res. ctx -> (k, res) Fun.args -> k -> res Lwt.t =
fun ctx -> function
| [] -> fun x -> Lwt.return x
| Map (args', f') :: tl ->
fun f -> go ctx args' f' >>= fun v -> go ctx tl (f v)
| Opt value :: tl -> fun f -> find value ctx >>= fun v -> go ctx tl (f v)
| Dft (v, value) :: tl -> (
fun f ->
find value ctx >>= function
| Some v' ->
Log.debug (fun m ->
m "Found a value for the default argument: %a." pp_value value);
go ctx tl (f v')
| None -> go ctx tl (f v))
| Req value :: tl -> (
fun f ->
find value ctx >>= function
| Some v -> go ctx tl (f v)
| None -> Lwt.fail Not_found)
in
Lwt.catch (fun () -> go ctx args f >>= fun fiber -> fiber) @@ function
| Not_found -> Lwt.return_none
| exn -> Lwt.fail exn
and find : type a. a value -> ctx -> a option Lwt.t =
fun value ctx ->
match Hmap.find value ctx with
| None | Some [] -> Lwt.return_none
| Some lst ->
(* XXX(dinosaure): priority on values, then we apply the first [Fun] *)
let rec go fold lst =
match fold, lst with
| None, [] -> Lwt.return_none
| Some (Value.Fun (args, f)), [] -> apply ctx args f
| Some (Value.Val _), [] -> assert false
| None, (Value.Fun _ as x) :: r -> go (Some x) r
| _, Val v :: _ -> Lwt.return_some v
| Some _, Fun _ :: r -> go fold r
in
go None (List.rev lst)
(* XXX(dinosaure): the most recent value. *)
type edn = Edn : 'edn value * 'edn -> edn
type fnu = Fun : 'edn value * ('k, 'edn option Lwt.t) Fun.args * 'k -> fnu
type dep = Dep : 'edn value -> dep
let pp_fnu ppf (Fun (dep, _, _)) =
Format.fprintf ppf "%a" pp_info (Hmap0.Key.info dep)
module Sort = struct
type t =
| Val : 'edn value * 'edn -> t
| Fun : 'edn value * ('k, 'edn option Lwt.t) Fun.args * 'k -> t
let pp ppf = function
| Val (k, _) -> pp_info ppf (Hmap0.Key.info k)
| Fun (k, _, _) -> pp_info ppf (Hmap0.Key.info k)
end
let partition bindings =
let rec go leafs nodes = function
| [] -> List.rev leafs, List.rev nodes
| Hmap.B (_, []) :: r -> go leafs nodes r
| Hmap.B (k, Val v :: tl) :: r ->
go (Sort.Val (k, v) :: leafs) nodes (Hmap.B (k, tl) :: r)
| Hmap.B (k, Fun (args, f) :: tl) :: r ->
go leafs (Fun (k, args, f) :: nodes) (Hmap.B (k, tl) :: r)
in
go [] [] bindings
let exists k bindings =
let rec go k = function
| [] -> false
| Hmap.B (k', _) :: r -> (
match Hmap0.Key.proof k k' with Some _ -> true | None -> go k r)
in
go k bindings
let dependencies (Fun (_, args, _)) bindings =
let rec go : type k r. _ -> (k, r) Fun.args -> _ =
fun acc -> function
| Fun.Req dep :: r -> go (Dep dep :: acc) r
| Fun.Opt dep :: r when exists dep bindings -> go (Dep dep :: acc) r
| Fun.Dft (_, dep) :: r when exists dep bindings -> go (Dep dep :: acc) r
| _ :: r -> go acc r
| [] -> List.rev acc
in
go [] args
let exists leafs (Dep k) =
let rec go = function
| [] -> false
| Sort.Val (k', _) :: r -> (
match Hmap0.Key.proof k k' with Some _ -> true | None -> go r)
| Sort.Fun (k', _, _) :: r -> (
match Hmap0.Key.proof k k' with Some _ -> true | None -> go r)
in
go leafs
let pp_list pp ppf lst =
let rec go = function
| [] -> ()
| [ x ] -> Format.fprintf ppf "%a" pp x
| x :: r ->
Format.fprintf ppf "%a;@ " pp x;
go r
in
Format.fprintf ppf "@[<1>[";
go lst;
Format.fprintf ppf "]@]"
let sort bindings =
let rec go acc later todo progress =
match todo, later with
| [], [] -> List.rev acc
| [], _ when progress -> go acc [] later false
| [], later ->
(* TODO(dinosaure): check, at least, one root in [acc]. *)
Log.debug (fun m ->
m "Found a solution only for: @[<hov>%a@]." (pp_list Sort.pp) acc);
Log.debug (fun m ->
m "Unsolvable values: @[<hov>%a@]." (pp_list pp_fnu) later);
List.rev acc
| (Fun (k, args, f) as x) :: xs, _ ->
let deps = dependencies x bindings in
let available = List.for_all (exists acc) deps in
if available then go (Sort.Fun (k, args, f) :: acc) later xs true
else go acc (x :: later) xs progress
in
let leafs, nodes = partition bindings in
Log.debug (fun m -> m "Partition done.");
Log.debug (fun m -> m "Nodes: @[<hov>%a@]." (pp_list pp_fnu) nodes);
go leafs [] nodes false
let inf = -1 and sup = 1
let priority_compare (Edn (k0, _)) (Edn (k1, _)) =
match (Hmap0.Key.info k0).root, (Hmap0.Key.info k1).root with
| Root (Some p0), Root (Some p1) -> p0 - p1
| (Root None | Value), Root (Some _) -> sup
| Root (Some _), (Root None | Value) -> inf
| Value, Value -> 0
| Root None, Root None -> 0
| Value, Root None -> sup
| Root None, Value -> inf
let unfold : ctx -> (edn list, [> `Cycle ]) result Lwt.t =
fun ctx ->
let open Lwt.Infix in
let rec go ctx acc : Sort.t list -> _ = function
| [] ->
(* XXX(dinosaure): here, we use a stable sort, [List.rev]
* is needed to keep a certain topological order - see [sort].
* [stable_sort] keeps this order too. *)
let acc = List.stable_sort priority_compare (List.rev acc) in
Lwt.return_ok acc
| Sort.Val (k, v) :: r ->
Log.debug (fun m -> m "Return a value %a." pp_value k);
go ctx (Edn (k, v) :: acc) r
| Sort.Fun (k, args, f) :: r -> (
Log.debug (fun m -> m "Apply a function %a." pp_value k);
apply ctx args f >>= function
| Some v -> go (add k v ctx) (Edn (k, v) :: acc) r
| None -> go ctx acc r)
in
let ordered_bindings = sort (Hmap.bindings ctx) in
go ctx [] ordered_bindings
let flow_of_value :
type edn. edn value -> edn -> (flow, [> error ]) result Lwt.t =
fun k v ->
let open Lwt.Infix in
let rec go : Implicit1.pack list -> _ = function
| [] -> Lwt.return_error `Not_found
| Implicit1.Key (Protocol (k', (module Witness), (module Protocol))) :: r
-> (
match Hmap0.Key.proof k k' with
| None -> go r
| Some Teq -> (
Protocol.connect v >>= function
| Ok flow -> Lwt.return_ok (Witness.T flow)
| Error _err -> go r))
in
go (Implicit1.bindings ())
type ('a, 'b) refl = Refl : ('a, 'a) refl
let equal : type a b. a value -> b value -> (a, b) refl option =
fun a b ->
match Hmap0.Key.proof a b with Some Teq -> Some Refl | None -> None
let rec connect : edn list -> (flow, [> error ]) result Lwt.t = function
| [] -> Lwt.return_error `Not_found
| Edn (k, v) :: r -> (
let open Lwt.Infix in
Log.debug (fun m -> m "Try to instantiate %a." pp_value k);
flow_of_value k v >>= function
| Ok _ as v -> Lwt.return v
| Error _err -> connect r)
let resolve : ctx -> (flow, [> error ]) result Lwt.t =
fun ctx ->
let open Lwt.Infix in
unfold ctx >>= function
| Ok lst ->
Log.debug (fun m ->
m "List of endpoints: @[<hov>%a@]"
(pp_list (fun ppf (Edn (k, _)) -> pp_value ppf k))
lst);
connect lst
| Error _ as err -> Lwt.return err
let make ~name = Hmap0.Key.create { name; root = Value }
let empty = Hmap.empty
let get value ctx =
match Hmap.find value ctx with
| Some lst ->
let rec first = function
| [] -> None
| Value.Val v :: _ -> Some v
| _ :: r -> first r
in
first lst
| None -> None