(** Database handle and operations *)

type t =
  { path : string [@warning "-69"]
  ; meta : Types.metadata
  }

let open_db path =
  match Io.read_header path with
  | Ok meta -> Ok { path; meta }
  | Error (Error.IO_error _) ->
    Result.bind (Io.create_database path 4096) (fun () ->
      Result.map (fun meta -> { path; meta }) (Io.read_header path))
  | Error err -> Error err
;;

let close _ = Ok ()

let metadata db = db.meta

let view _ f =
  let txn : Types.ro Txn.t = Obj.magic () in
  f txn
;;

let update _ f =
  let txn : Types.rw Txn.t = Obj.magic () in
  f txn
;;