(************************************************************************)
(* This file is part of SKS.  SKS 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
   USA *)
(***********************************************************************)

(** Version of the [Channel] objects that keeps track of the number of bytes
  sent through them. *)
open StdLabels
open MoreLabels
module Unix=UnixLabels


class metered_out_channel outc = 
object (self)
  inherit Channel.out_channel_obj

  val mutable count = 0

  method private incr c = count <- count + c

  method write_string str =
    outc#write_string str;
    self#incr (String.length str)

  method write_string_pos ~buf ~pos ~len =
    outc#write_string_pos ~buf ~pos ~len;
    self#incr len

  method write_char char =
    outc#write_char char;
    self#incr 1

  method write_byte byte =
    outc#write_byte byte;
    self#incr 1

  method flush : unit = outc#flush
  method upcast = (self :> Channel.out_channel_obj)
  method reset = count <- 0
  method bytes = count

end


class metered_in_channel inc = 
object (self)
  inherit Channel.in_channel_obj

  val mutable count = 0

  method private incr c = count <- count + c

  method read_string len =
    self#incr len;
    inc#read_string len

  method read_string_pos ~buf ~pos ~len =
    self#incr len;
    inc#read_string_pos ~buf ~pos ~len 

  method read_char = 
    self#incr 1;
    inc#read_char

  method read_byte =
    self#incr 1;
    inc#read_byte

  method upcast = (self :> Channel.in_channel_obj)
  method reset = count <- 0
  method bytes = count

end