(* Guestfs Browser.
 * Copyright (C) 2010 Red Hat Inc.
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *)

let canonical dev =
  let len = String.length dev in
  if len >= 8 &&
    dev.[0] = '/' &&
    dev.[1] = 'd' && dev.[2] = 'e' && dev.[3] = 'v' &&
    dev.[4] = '/' &&
    (dev.[5] = 'h' || dev.[5] = 's' || dev.[5] = 'v') &&
    dev.[6] = 'd' &&
    dev.[7] >= 'a' && dev.[7] <= 'z' then (
      let dev = String.copy dev in
      dev.[5] <- 's';
      dev
    )
  else
    dev

let canonical_compare dev1 dev2 =
  let dev1 = canonical dev1 in
  let dev2 = canonical dev2 in
  String.compare dev1 dev2

module DeviceSet = struct
  include Set.Make (
    struct
      type t = String.t
      let compare = canonical_compare
    end
  )

  let subtract = diff

  let of_list ds =
    List.fold_left (fun set d -> add (canonical d) set) empty ds

  let of_array ds =
    of_list (Array.to_list ds)

  let to_string t =
    "{" ^ String.concat " " (elements t) ^ "}"
end