(* virt-dmesg
 * (C) Copyright 2008-2011 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *)

open Printf

module StringMap = Map.Make (String)

type symbol_table = int64 StringMap.t

let ( +^ ) = Int64.add
let ( -^ ) = Int64.sub
let ( *^ ) = Int64.mul
let ( /^ ) = Int64.div
let ( &^ ) = Int64.logand

let frequency xs =
  let xs = List.sort compare xs in
  let rec loop = function
    | [] -> []
    | [x] -> [1, x]
    | x :: y :: xs when x = y ->
        let rest = loop (y :: xs) in
        let (count, _), rest = List.hd rest, List.tl rest in
        (count+1, y) :: rest
    | x :: xs ->
        (1, x) :: loop xs
  in
  let xs = loop xs in
  List.rev (List.sort compare xs)

let rec filter_map f = function
  | [] -> []
  | x :: xs ->
      match f x with
      | None -> filter_map f xs
      | Some y -> y :: filter_map f xs

let replace_chars f s =
  let len = String.length s in
  let rec loop i acc =
    if i < len then (
      let c = String.unsafe_get s i in
      let acc = f c :: acc in
      loop (i+1) acc
    ) else
      String.concat "" (List.rev acc)
  in
  loop 0 []

let program_name = ref "virt-dmesg"
let set_program_name str = program_name := str
let get_program_name () = !program_name

let debug_mode = ref false
let set_debug () = debug_mode := true
let debug fs = ksprintf (fun str -> if !debug_mode then print_endline str) fs

let error fs =
  ksprintf (
    fun str ->
      prerr_string !program_name;
      prerr_string ": ";
      prerr_endline str
  ) fs