%%%-------------------------------------------------------------------
%%% File    : sherk_tab.erl
%%% Author  : Mats Cronqvist <locmacr@mwlx084>
%%% Description :
%%%
%%% Created : 21 Aug 2006 by Mats Cronqvist <locmacr@mwlx084>
%%%-------------------------------------------------------------------
-module(sherk_tab).

-export([assert/1,check_file/1]).

-include_lib("kernel/include/file.hrl").

-include("log.hrl").

assert(File) ->
  TabFile = filename:dirname(File)++"/."++filename:basename(File,".trz")++".etz",
  {ok,#file_info{mtime=MT}} = file:read_file_info(File),
  case file:read_file_info(TabFile) of
    {ok,#file_info{mtime=TabMT}} when MT < TabMT ->
      %% the tab file exists and is up-to-date
      case sherk_ets:lup(sherk_prof, file) of
        File -> ?log({is_cached,TabFile});
        _ ->
          ?log(restoring_tab),
          try sherk_ets:f2t(TabFile)
          catch
            _:X ->
              ?log({deleting_bad_tab_file,X}),
              file:delete(TabFile),
              assert(File)
          end
      end;
    _ ->
      %% make tab and save it
      ?log([creating_tab]),
      sherk_scan:go(File,'',sherk_prof,0,''),
      ets:insert(sherk_prof, {file, File}),
      try
        ?log(storing_tab),
        sherk_ets:t2f([sherk_prof,sherk_scan],TabFile)
      catch
        _:_ -> ?log({creation_failed,TabFile})
      end
  end,
  ?log([folding_pids]),
  ets:foldl(fun store_pid/2, [], sherk_prof),
  ?log([done]).

store_pid({{{pid,time},P},_},_) -> ets:insert(sherk_prof,{sherk:to_str(P),P});
store_pid(_,_) -> ok.

check_file(File) -> ".trz" = filename:extension(File).