mod_statistics_mem/mod_statistics_mem.lua

   1 -- Probably Linux-specific memory statistics
   2
   3 module:set_global();
   4
   5 local human;
   6 do
   7         local tostring = tostring;
   8         local s_format = string.format;
   9         local m_floor = math.floor;
  10         local m_max = math.max;
  11         local prefixes = "kMGTPEZY";
  12         local multiplier = 1024;
  13
  14         function human(num)
  15                 num = tonumber(num) or 0;
  16                 local m = 0;
  17                 while num >= multiplier and m < #prefixes do
  18                         num = num / multiplier;
  19                         m = m + 1;
  20                 end
  21
  22                 return s_format("%0."..m_max(0,3-#tostring(m_floor(num))).."f%sB",
  23                 num, m > 0 and (prefixes:sub(m,m) .. "i") or "");
  24         end
  25 end
  26
  27
  28 local pagesize = 4096; -- according to getpagesize()
  29 module:provides("statistics", {
  30         statistics = {
  31                 memory_total = { -- virtual memory
  32                         get = function ()
  33                                 local statm, err = io.open"/proc/self/statm";
  34                                 if statm then
  35                                         local total = statm:read"*n";
  36                                         statm:close();
  37                                         return total * pagesize;
  38                                 else
  39                                         module:log("debug", err);
  40                                 end
  41                         end;
  42                         tostring = human;
  43                 };
  44                 memory_rss = { -- actual in-memory data size
  45                         get = function ()
  46                                 local statm, err = io.open"/proc/self/statm";
  47                                 if statm then
  48                                         statm:read"*n"; -- Total size, ignore
  49                                         local rss = statm:read"*n";
  50                                         statm:close();
  51                                         return rss * pagesize;
  52                                 else
  53                                         module:log("debug", err);
  54                                 end
  55                         end;
  56                         tostring = human;
  57                 };
  58         }
  59 });