ligo/vendors/irmin-lmdb/irmin_lmdb.ml
2018-09-12 14:58:44 +02:00

661 lines
19 KiB
OCaml

(*
* Copyright (c) 2013-2017 Thomas Gazagnaire <thomas@gazagnaire.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*)
module Option = struct
let of_result = function
| Ok v -> Some v
| _ -> None
let value_map ~default ~f = function
| None -> default
| Some v -> f v
end
module Result = struct
let map ~f = function
| Ok v -> Ok (f v)
| Error err -> Error err
end
let cstruct_of_ba_copy ba =
let cs = Cstruct.of_bigarray ba in
let len = Cstruct.len cs in
let cs_copy = Cstruct.create_unsafe len in
Cstruct.blit cs 0 cs_copy 0 len ;
cs_copy
open Lwt.Infix
type t = {
db: Lmdb.t ;
root: string ;
}
let of_result = function
| Ok v -> Lwt.return v
| Error err -> Lwt.fail_with (Lmdb.string_of_error err)
let src = Logs.Src.create "irmin.lmdb" ~doc:"Irmin in a Lmdb store"
module Log = (val Logs.src_log src : Logs.LOG)
let int64_of_string s =
try Ok (Int64.of_string s)
with Failure _ ->
Error (`Msg (Printf.sprintf "%s is not the representation of an int64" s))
let bool_of_string s =
try Ok (bool_of_string s)
with Failure _ ->
Error (`Msg (Printf.sprintf "%s is not the representation of a boolean" s))
let int64_converter = int64_of_string, Fmt.uint64
let bool_converter = bool_of_string, Fmt.bool
module Conf = struct
let root = Irmin.Private.Conf.root
let mapsize =
Irmin.Private.Conf.key "mapsize" int64_converter 40_960_000_000L
let readonly =
Irmin.Private.Conf.key "readonly" bool_converter false
end
let config
?(config=Irmin.Private.Conf.empty) ?mapsize ?(readonly=false) file =
let module C = Irmin.Private.Conf in
let config = C.add config Conf.root (Some file) in
let config = C.add config Conf.readonly readonly in
Option.value_map mapsize ~default:config ~f:(C.add config Conf.mapsize)
let mem db k =
Lmdb.with_ro_db db ~f:(fun txn db -> Lmdb.mem txn db k) |>
of_result
let find_bind db k ~f =
match Lmdb.with_ro_db db
~f:(fun txn db -> Result.map ~f (Lmdb.get txn db k)) with
| Error KeyNotFound -> Lwt.return_none
| Error err -> Lwt.fail_with (Lmdb.string_of_error err)
| Ok v -> Lwt.return v
let add db k v =
Lmdb.with_rw_db db ~f:begin fun txn db ->
Lmdb.put_string txn db k v ;
end |> of_result
let add_cstruct db k v =
Lmdb.with_rw_db db ~f:begin fun txn db ->
Lmdb.put txn db k (Cstruct.to_bigarray v) ;
end |> of_result
module Irmin_value_store
(M: Irmin.Metadata.S)
(H: Irmin.Hash.S)
(C: Irmin.Contents.S)
(P: Irmin.Path.S) = struct
module XContents = struct
type nonrec t = t
type key = H.t
type value = C.t
let lmdb_of_key h =
"contents/" ^ Cstruct.to_string (H.to_raw h)
let mem { db ; _ } key =
let key = lmdb_of_key key in
mem db key
let find { db ; _ } key =
let key = lmdb_of_key key in
find_bind db key ~f:begin fun v ->
Option.of_result (C.of_string Cstruct.(to_string (of_bigarray v)))
end
let to_string = Fmt.to_to_string C.pp
let add { db ; _ } v =
let k = H.digest C.t v in
let k_lmdb = lmdb_of_key k in
let v = to_string v in
add db k_lmdb v >|= fun () -> k
module Val = C
module Key = H
end
module Contents = Irmin.Contents.Store(XContents)
module XNode = struct
module Key = H
module Path = P
module Val = struct
module Metadata = M
type kind = [ `Node | `Contents of M.t ]
type metadata = M.t
type entry = { kind : kind; name : string; node : H.t; }
type t = entry list
type contents = Contents.key
type node = Key.t
type step = Path.step
type value = [`Node of node | `Contents of contents * metadata ]
let metadata_t = M.t
let contents_t = Contents.Key.t
let node_t = Key.t
let step_t = Path.step_t
let entry_t =
let open Irmin.Type in
record "Tree.entry"
(fun kind name node ->
let kind =
match kind with
| None -> `Node
| Some m -> `Contents m in
{ kind ; name ; node } )
|+ field "kind" (option M.t) (function
| { kind = `Node ; _ } -> None
| { kind = `Contents m ; _ } -> Some m)
|+ field "name" string (fun { name ; _ } -> name)
|+ field "node" H.t (fun { node ; _ } -> node)
|> sealr
let value_t =
let open Irmin.Type in
variant "Tree.value" (fun node contents -> function
| `Node n -> node n
| `Contents (c, m) -> contents (c, m))
|~ case1 "node" node_t (fun n -> `Node n)
|~ case1 "contents" (pair contents_t M.t) (fun (c, m) -> `Contents (c, m))
|> sealv
let of_step = Fmt.to_to_string P.pp_step
let to_step str = match P.step_of_string str with
| Ok x -> x
| Error (`Msg e) -> failwith e
let to_entry kind (name, node) =
{ kind; name = of_step name; node }
let list t =
List.fold_left (fun acc { kind; name; node } ->
let name = to_step name in
match kind with
| `Node -> (name, `Node node) :: acc
| `Contents m -> (name, `Contents (node, m)) :: acc
) [] t
|> List.rev
let find t s =
let s = of_step s in
let rec aux = function
| [] -> None
| x::xs when x.name <> s -> aux xs
| { kind; node; _ } :: _ ->
match kind with
| `Node -> Some (`Node node)
| `Contents m -> Some (`Contents (node, m))
in
aux t
type compare_result = LT | EQ | GT
module Sort_key: sig
type t
val of_entry: entry -> t
val of_contents: string -> t
val of_node: string -> t
val order: t -> t -> compare_result
val compare: t -> t -> int
end = struct
type t =
| Contents: string -> t
| Node : string -> t
exception Result of int
let str = function Contents s | Node s -> s
let compare x y = match x, y with
| Contents x, Contents y -> String.compare x y
| _ ->
let xs = str x and ys = str y in
let lenx = String.length xs in
let leny = String.length ys in
let i = ref 0 in
try
while !i < lenx && !i < leny do
match
Char.compare
(String.unsafe_get xs !i) (String.unsafe_get ys !i)
with
| 0 -> incr i
| i -> raise (Result i)
done;
let get len s i =
if i < len then String.unsafe_get (str s) i
else if i = len then match s with
| Node _ -> '/'
| Contents _ -> '\000'
else '\000'
in
match Char.compare (get lenx x !i) (get leny y !i) with
| 0 -> Char.compare (get lenx x (!i + 1)) (get leny y (!i + 1))
| i -> i
with Result i ->
i
let order a b = match compare a b with
| 0 -> EQ
| x when x > 0 -> GT
| _ -> LT
let of_contents c = Contents c
let of_node n = Node n
let of_entry = function
| {name = n; kind = `Node; _} -> of_node n
| {name = n; kind = `Contents _; _} -> of_contents n
end
let compare_entries a b =
Sort_key.(compare (of_entry a) (of_entry b))
(* the order is always:
[ ...; foo (content key); ...; foo/ (node key); ... ]
So always scan until the 'node' key.
*)
let remove t step =
let step = of_step step in
let node_key = Sort_key.of_node step in
let contents_key = Sort_key.of_contents step in
let return ~acc rest = List.rev_append acc rest in
let rec aux acc = function
| [] -> t
| h :: l ->
let entry_key = Sort_key.of_entry h in
if Sort_key.order contents_key entry_key = EQ then
return ~acc l
else match Sort_key.order node_key entry_key with
| GT -> aux (h :: acc) l
| EQ -> return ~acc l
| LT -> t
in
aux [] t
let hash_of_v = function
| `Contents (x, _) | `Node x -> x
let update t step v =
let step = of_step step in
let node_key = Sort_key.of_node step in
let contents_key = Sort_key.of_contents step in
let return ~acc rest =
let kind, node = match v with
| `Node n -> `Node, n
| `Contents (c, m) -> `Contents m, c
in
let e = { kind; name = step; node} in
List.rev_append acc (e :: rest)
in
let rec aux acc = function
| [] -> return ~acc []
| { node; _ } as h :: l ->
let entry_key = Sort_key.of_entry h in
(* Remove any contents entry with the same name. This will always
come before the new succ entry. *)
if Sort_key.order contents_key entry_key = EQ then
aux acc l
else match Sort_key.order node_key entry_key with
| GT -> aux (h :: acc) l
| LT -> return ~acc (h::l)
| EQ when Cstruct.equal (H.to_raw (hash_of_v v)) (H.to_raw node) -> t
| EQ -> return ~acc l
in
aux [] t
let empty = []
let is_empty = function
| [] -> true
| _ -> false
let v alist =
let alist = List.map (fun (l, x) ->
let v k = l, k in
match x with
| `Node n -> to_entry `Node (v n)
| `Contents (c, m) -> to_entry (`Contents m) (v c)
) alist
in
List.fast_sort compare_entries alist
let alist t =
let mk_n k = `Node k in
let mk_c k m= `Contents (k, m) in
List.map (function
| { kind = `Node; name; node } -> (to_step name, mk_n node)
| { kind = `Contents m; name; node; _ } ->
(to_step name, mk_c node m)
) t
module N = Irmin.Private.Node.Make (H)(H)(P)(M)
let to_n t = N.v (alist t)
let of_n n = v (N.list n)
let t = Irmin.Type.like N.t of_n to_n
end
module AO = struct
type nonrec t = t
type key = H.t
type value = Val.t
let lmdb_of_key h =
"node/" ^ Cstruct.to_string (H.to_raw h)
let mem { db ; _ } key =
let key = lmdb_of_key key in
mem db key
let of_cstruct v =
Irmin.Type.decode_cstruct (Irmin.Type.list Val.entry_t) v |>
Option.of_result
let find { db ; _ } key =
let key = lmdb_of_key key in
find_bind db key ~f:(fun v -> of_cstruct (cstruct_of_ba_copy v))
let add { db ; _ } v =
let v = Irmin.Type.encode_cstruct (Irmin.Type.list Val.entry_t) v in
let k = H.digest Irmin.Type.cstruct v in
let k_lmdb = lmdb_of_key k in
add_cstruct db k_lmdb v >|= fun () -> k
end
include AO
end
module Node = Irmin.Private.Node.Store(Contents)(P)(M)(XNode)
module XCommit = struct
module Val = struct
type t = {
node: H.t ;
parents: H.t list ;
info: Irmin.Info.t ;
}
type commit = H.t
type node = H.t
let commit_t = H.t
let node_t = H.t
let v ~info ~node ~parents = { info ; node ; parents }
let xnode { node; _ } = node
let node t = xnode t
let parents { parents; _ } = parents
let info { info; _ } = info
module C = Irmin.Private.Commit.Make(H)(H)
let of_c c = v ~info:(C.info c) ~node:(C.node c) ~parents:(C.parents c)
let to_c { info ; node ; parents } =
C.v ~info ~node ~parents
let t = Irmin.Type.like C.t of_c to_c
end
module Key = H
module AO = struct
let lmdb_of_key h =
"commit/" ^ Cstruct.to_string (H.to_raw h)
type nonrec t = t
type key = H.t
type value = Val.t
let mem { db ; _ } key =
let key = lmdb_of_key key in
mem db key
let of_cstruct v =
Irmin.Type.decode_cstruct Val.t v |>
Option.of_result
let find { db ; _ } key =
let key = lmdb_of_key key in
find_bind db key ~f:(fun v -> of_cstruct (cstruct_of_ba_copy v))
let add { db ; _ } v =
let v = Irmin.Type.encode_cstruct Val.t v in
let k = H.digest Irmin.Type.cstruct v in
let k_lmdb = lmdb_of_key k in
add_cstruct db k_lmdb v >|= fun () -> k
end
include AO
end
module Commit = Irmin.Private.Commit.Store(Node)(XCommit)
end
module type Branch = sig
include Irmin.Branch.S
val pp_ref: t Fmt.t
val of_ref: string -> (t, [`Msg of string]) result
end
module Branch (B: Irmin.Branch.S): Branch with type t = B.t = struct
open Astring
include B
let pp_ref ppf b = Fmt.pf ppf "heads/%a" B.pp b
let of_ref str = match String.cuts ~sep:"/" str with
| "heads" :: b -> B.of_string (String.concat ~sep:"/" b)
| _ -> Error (`Msg (Fmt.strf "%s is not a valid branch" str))
end
module Irmin_branch_store (B: Branch) (H: Irmin.Hash.S) = struct
module Key = B
module Val = H
module W = Irmin.Private.Watch.Make(Key)(Val)
type nonrec t = {
db: t;
w: W.t;
}
let watches = Hashtbl.create 10
type key = Key.t
type value = Val.t
type watch = W.watch * (unit -> unit Lwt.t)
(* let branch_of_lmdb r = *)
(* let str = String.trim @@ Git.Reference.to_raw r in *)
(* match B.of_ref str with *)
(* | Ok r -> Some r *)
(* | Error (`Msg _) -> None *)
let lmdb_of_branch r = Fmt.to_to_string B.pp_ref r
let mem { db ; _ } r =
mem db.db (lmdb_of_branch r)
let find { db ; _ } r =
find_bind db.db (lmdb_of_branch r)
~f:(fun v -> Some (H.of_raw (cstruct_of_ba_copy v)))
let listen_dir _ =
Lwt.return (fun () -> Lwt.return_unit)
let watch_key t key ?init f =
listen_dir t >>= fun stop ->
W.watch_key t.w key ?init f >|= fun w ->
(w, stop)
let watch t ?init f =
listen_dir t >>= fun stop ->
W.watch t.w ?init f >|= fun w ->
(w, stop)
let unwatch t (w, stop) =
stop () >>= fun () ->
W.unwatch t.w w
let v db (* ~head *) =
let w =
try Hashtbl.find watches db.root
with Not_found ->
let w = W.v () in
(* FIXME: we might want to use a weak table *)
Hashtbl.add watches db.root w;
w
in
Lwt.return { db ; w }
let list _ = Lwt.return_nil (* TODO, or not *)
(* let write_index _t _gr _gk = *)
(* Lwt.return_unit *)
let set _t r _k =
Log.debug (fun f -> f "update %a" B.pp r);
Lwt.return_unit
(* let gr = git_of_branch r in *)
(* let gk = git_of_commit k in *)
(* G.write_reference t.t gr gk >>= fun () -> *)
(* W.notify t.w r (Some k) >>= fun () -> *)
(* write_index t gr (Git.Hash.to_commit gk) *)
let remove _t r =
Log.debug (fun f -> f "remove %a" B.pp r);
Lwt.return_unit
(* G.remove_reference t.t (git_of_branch r) >>= fun () -> *)
(* W.notify t.w r None *)
let test_and_set _t _r ~test:_ ~set:_ =
Log.debug (fun f -> f "test_and_set");
Lwt.return_true
(* let gr = git_of_branch r in *)
(* let c = function None -> None | Some h -> Some (git_of_commit h) in *)
(* G.test_and_set_reference t.t gr ~test:(c test) ~set:(c set) >>= fun b -> *)
(* (if b then W.notify t.w r set else Lwt.return_unit) >>= fun () -> *)
(* begin *)
(* We do not protect [write_index] because it can take a log
time and we don't want to hold the lock for too long. Would
be safer to grab a lock, although the expanded filesystem
is not critical for Irmin consistency (it's only a
convenience for the user). *)
(* if b then match set with *)
(* | None -> Lwt.return_unit *)
(* | Some v -> write_index t gr (Git.Hash.to_commit (git_of_commit v)) *)
(* else *)
(* Lwt.return_unit *)
(* end >|= fun () -> *)
(* b *)
end
module Make
(M: Irmin.Metadata.S)
(C: Irmin.Contents.S)
(P: Irmin.Path.S)
(B: Irmin.Branch.S)
(H: Irmin.Hash.S) = struct
module P = struct
module Branch = Irmin_branch_store(Branch(B))(H)
include Irmin_value_store(M)(H)(C)(P)
module Slice = Irmin.Private.Slice.Make(Contents)(Node)(Commit)
module Sync = struct
type t = unit
type commit = H.t
type branch = B.t
let fetch _ ?depth:_ ~uri:_ _ = Lwt.return_error `Not_available
let push _ ?depth:_ ~uri:_ _ = Lwt.return_error `Not_available
let v _ = Lwt.return_unit
end
module Repo = struct
type nonrec t = {
config: Irmin.config ;
db: t ;
branch: Branch.t ;
}
let branch_t t : Branch.t = t.branch
let contents_t t : Contents.t = t.db
let node_t t : Node.t = contents_t t, t.db
let commit_t t : Commit.t = node_t t, t.db
type config = {
root : string option ;
mapsize : int64 ;
readonly : bool ;
(* TODO *)
(* ?write_buffer_size:int -> *)
(* ?max_open_files:int -> *)
(* ?block_size:int -> *)
(* ?block_restart_interval:int -> *)
(* ?cache_size:int *)
}
let config c =
let root = Irmin.Private.Conf.get c Conf.root in
let mapsize = Irmin.Private.Conf.get c Conf.mapsize in
let readonly = Irmin.Private.Conf.get c Conf.readonly in
{ root ; mapsize ; readonly }
let v conf =
let { root ; mapsize ; readonly } = config conf in
let root = match root with None -> "irmin.ldb" | Some root -> root in
if not (Sys.file_exists root) then Unix.mkdir root 0o755 ;
let flags = Lmdb.NoRdAhead :: Lmdb.NoTLS :: if readonly then [ Lmdb.RdOnly ] else [] in
let file_flags = if readonly then 0o444 else 0o644 in
match Lmdb.opendir ~mapsize ~flags root file_flags with
| Error err -> Lwt.fail_with (Lmdb.string_of_error err)
| Ok db ->
let db = { db ; root } in
Branch.v db >|= fun branch ->
{ db; branch; config = conf }
end
end
include Irmin.Make_ext(P)
end
include Conf