src/jit/zone.lua

   1 ----------------------------------------------------------------------------
   2 -- LuaJIT profiler zones.
   3 --
   4 -- Copyright (C) 2005-2013 Mike Pall. All rights reserved.
   5 -- Released under the MIT license. See Copyright Notice in luajit.h
   6 ----------------------------------------------------------------------------
   7 --
   8 -- This module implements a simple hierarchical zone model.
   9 --
  10 -- Example usage:
  11 --
  12 --   local zone = require("jit.zone")
  13 --   zone("AI")
  14 --   ...
  15 --     zone("A*")
  16 --     ...
  17 --     print(zone:get()) --> "A*"
  18 --     ...
  19 --     zone()
  20 --   ...
  21 --   print(zone:get()) --> "AI"
  22 --   ...
  23 --   zone()
  24 --
  25 ----------------------------------------------------------------------------
  26
  27 local remove = table.remove
  28
  29 return setmetatable({
  30   flush = function(t)
  31     for i=#t,1,-1 do t[i] = nil end
  32   end,
  33   get = function(t)
  34     return t[#t]
  35   end
  36 }, {
  37   __call = function(t, zone)
  38     if zone then
  39       t[#t+1] = zone
  40     else
  41       return (assert(remove(t), "empty zone stack"))
  42     end
  43   end
  44 })
  45