lib/etorrent-1.0/src/etorrent_time.erl

   1 %%%-------------------------------------------------------------------
   2 %%% File    : etorrent_date.erl
   3 %%% Author  : Jesper Louis Andersen <jlouis@ogre.home>
   4 %%% Description : Library functions for date manipulation
   5 %%%
   6 %%% Created : 19 Jul 2008 by Jesper Louis Andersen <jlouis@ogre.home>
   7 %%%-------------------------------------------------------------------
   8 -module(etorrent_time).
   9
  10 %% API
  11 -export([now_add_seconds/2, now_subtract_seconds/2]).
  12
  13 %%====================================================================
  14 %% API
  15 %%====================================================================
  16 %%--------------------------------------------------------------------
  17 %% Function: now_subtract(NT, Millisecs) -> NT
  18 %% Args:    NT ::= {Megasecs, Secs, Millisecs}
  19 %%          Megasecs = Secs = Millisecs = integer()
  20 %% Description: Subtract a time delta in millsecs from a now() triple
  21 %%--------------------------------------------------------------------
  22 now_subtract_seconds({Megasecs, Secs, Ms}, Subsecs) ->
  23     case Secs - Subsecs of
  24         N when N >= 0 ->
  25             {Megasecs, N, Ms};
  26         N ->
  27             Needed = abs(N) div 1000000 + 1,
  28             {Megasecs - Needed, N + (Needed * 1000000), Ms}
  29     end.
  30
  31 now_add_seconds({Megasecs, Secs, Ms}, Add) ->
  32     case Secs + Add of
  33         K when K < 1000000 ->
  34             {Megasecs, K, Ms};
  35         K ->
  36             {Megasecs + K div 1000000, K rem 1000000, Ms}
  37     end.
  38
  39 %%====================================================================
  40 %% Internal functions
  41 %%====================================================================