-- Probably Linux-specific memory statistics

module:set_global();

local human;

do

	local tostring = tostring;

	local s_format = string.format;

	local m_floor = math.floor;

	local m_max = math.max;

	local prefixes = "kMGTPEZY";

	local multiplier = 1024;

	function human(num)

		num = tonumber(num) or 0;

		local m = 0;

		while num >= multiplier and m < #prefixes do

			num = num / multiplier;

			m = m + 1;

		end

		return s_format("%0."..m_max(0,3-#tostring(m_floor(num))).."f%sB",

		num, m > 0 and (prefixes:sub(m,m) .. "i") or "");

	end

end

local pagesize = 4096; -- according to getpagesize()

module:provides("statistics", {

	statistics = {

		memory_total = { -- virtual memory

			get = function ()

				local statm, err = io.open"/proc/self/statm";

				if statm then

					local total = statm:read"*n";

					statm:close();

					return total * pagesize;

				else

					module:log("debug", err);

				end

			end;

			tostring = human;

		};

		memory_rss = { -- actual in-memory data size

			get = function ()

				local statm, err = io.open"/proc/self/statm";

				if statm then

					statm:read"*n"; -- Total size, ignore

					local rss = statm:read"*n";

					statm:close();

					return rss * pagesize;

				else

					module:log("debug", err);

				end

			end;

			tostring = human;

		};

	}

});