tree.ml
(*****************************************************************************)
(* *)
(* Open Source License *)
(* Copyright (c) 2022 TriliTech <contact@trili.tech> *)
(* Copyright (c) 2022 Nomadic Labs <contact@nomadic-labs.com> *)
(* *)
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(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
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(*****************************************************************************)
type tree_instance = ..
type key = string list
type value = bytes
exception Incorrect_tree_type
module type S = sig
type tree
val select : tree_instance -> tree
val wrap : tree -> tree_instance
val remove : tree -> key -> tree Lwt.t
val add : tree -> key -> value -> tree Lwt.t
val add_tree : tree -> key -> tree -> tree Lwt.t
val find : tree -> key -> value option Lwt.t
val find_tree : tree -> key -> tree option Lwt.t
val hash : tree -> Context_hash.t
val length : tree -> key -> int Lwt.t
val list :
tree -> ?offset:int -> ?length:int -> key -> (string * tree) list Lwt.t
end
type 'tree backend = (module S with type tree = 'tree)
let select : type tree. tree backend -> tree_instance -> tree =
fun (module T) tree -> T.select tree
let wrap : type tree. tree backend -> tree -> tree_instance =
fun (module T) tree -> T.wrap tree
let remove : type tree. tree backend -> tree -> key -> tree Lwt.t =
fun (module T) tree key -> T.remove tree key
let add : type tree. tree backend -> tree -> key -> value -> tree Lwt.t =
fun (module T) tree key value -> T.add tree key value
let add_tree : type tree. tree backend -> tree -> key -> tree -> tree Lwt.t =
fun (module T) tree key subtree -> T.add_tree tree key subtree
let find : type tree. tree backend -> tree -> key -> value option Lwt.t =
fun (module T) tree key -> T.find tree key
let find_tree : type tree. tree backend -> tree -> key -> tree option Lwt.t =
fun (module T) tree key -> T.find_tree tree key
let hash : type tree. tree backend -> tree -> Context_hash.t =
fun (module T) tree -> T.hash tree
let length : type tree. tree backend -> tree -> key -> int Lwt.t =
fun (module T) tree key -> T.length tree key
let list :
type tree.
tree backend ->
tree ->
?offset:int ->
?length:int ->
key ->
(string * tree) list Lwt.t =
fun (module T) tree ?offset ?length key -> T.list tree ?offset ?length key
type wrapped_tree = Wrapped_tree : 'tree * 'tree backend -> wrapped_tree
type tree_instance += Wrapped of wrapped_tree
module Wrapped : S with type tree = wrapped_tree = struct
type tree = wrapped_tree
let remove (Wrapped_tree (t, b)) key =
let open Lwt.Syntax in
let+ t = remove b t key in
Wrapped_tree (t, b)
let add (Wrapped_tree (t, b)) key v =
let open Lwt.Syntax in
let+ t = add b t key v in
Wrapped_tree (t, b)
let add_tree (Wrapped_tree (t, b)) key (Wrapped_tree (t', b')) =
let open Lwt.Syntax in
let t' = select b (wrap b' t') in
let+ t = add_tree b t key t' in
Wrapped_tree (t, b)
let find_tree (Wrapped_tree (t, b)) key =
let open Lwt.Syntax in
let+ t' = find_tree b t key in
match t' with Some t' -> Some (Wrapped_tree (t', b)) | None -> None
let length (Wrapped_tree (t, b)) key = length b t key
let list (Wrapped_tree (t, b)) ?offset ?length key =
let open Lwt.Syntax in
let+ list = list b t ?offset ?length key in
List.map (fun (step, tree) -> (step, Wrapped_tree (tree, b))) list
let find (Wrapped_tree (t, b)) key = find b t key
let hash (Wrapped_tree (t, b)) = hash b t
let select = function
| Wrapped (Wrapped_tree (_, _) as wt) -> wt
| _ -> raise Incorrect_tree_type
let wrap t = Wrapped t
end