luatz/tzcache.lua

   1 local read_tzfile = require "luatz.tzfile".read_tzfile
   2
   3 local base_zoneinfo_path = "/usr/share/zoneinfo/"
   4 local local_zoneinfo_path = "/etc/localtime"
   5 local tz_cache = {}
   6
   7 local function name_to_zoneinfo_path(name)
   8         if name == nil then
   9                 return local_zoneinfo_path
  10         elseif name:sub(1, 1) == "/" then
  11                 return name
  12         else
  13                 return base_zoneinfo_path .. name
  14         end
  15 end
  16
  17 local function clear_tz_cache(name)
  18         tz_cache[name_to_zoneinfo_path(name)] = nil
  19 end
  20
  21 local function get_tz(name)
  22         local path = name_to_zoneinfo_path(name)
  23         -- TODO: stat path
  24         local tzinfo = tz_cache[path]
  25         if tzinfo == nil then
  26                 tzinfo = read_tzfile(path)
  27                 tz_cache[path] = tzinfo
  28         end
  29         return tzinfo
  30 end
  31
  32 return {
  33         get_tz = get_tz;
  34         clear_tz_cache = clear_tz_cache;
  35 }