From c8fdcd80b5e0aa59957c4c6234b58d743edb2e40 Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Mon, 30 Nov 2020 17:59:18 +0000
Subject: [PATCH] Precalc/reuse some tables and values

---
 nselib/base32.lua |  7 +++++--
 nselib/dhcp6.lua  |  5 +++--
 nselib/http.lua   | 10 +++++-----
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/nselib/base32.lua b/nselib/base32.lua
index 889790888..e830ce1eb 100644
--- a/nselib/base32.lua
+++ b/nselib/base32.lua
@@ -108,7 +108,10 @@ function enc (p, hexExtend)
 end
 
 
-local db32table_standard = setmetatable({}, {__index = function (t, k) error "invalid encoding: invalid character" end})
+local db32metatable = {
+  __index = function (t, k) error "invalid encoding: invalid character" end
+}
+local db32table_standard = setmetatable({}, db32metatable)
 do
     local r = {["="] = 0}
     for i, v in ipairs(b32standard) do
@@ -118,7 +121,7 @@ do
         db32table_standard[i] = r[char(i)]
     end
 end
-local db32table_hex = setmetatable({}, {__index = function (t, k) error "invalid encoding: invalid character" end})
+local db32table_hex = setmetatable({}, db32metatable)
 do
     local r = {["="] = 0}
     for i, v in ipairs(b32hexExtend) do
diff --git a/nselib/dhcp6.lua b/nselib/dhcp6.lua
index cba464360..3f242c652 100644
--- a/nselib/dhcp6.lua
+++ b/nselib/dhcp6.lua
@@ -62,6 +62,7 @@ DHCP6.OptionTypes = {
   OPTION_CLIENT_FQDN = 0x27,
 }
 
+local DHCP6_EPOCH = os.time({year=2000, day=1, month=1, hour=0, min=0, sec=0})
 -- DHCP6 options
 DHCP6.Option = {
 
@@ -110,7 +111,7 @@ DHCP6.Option = {
         type = DHCP6.OptionTypes.OPTION_CLIENTID,
         duid = duid or 1,
         hwtype = hwtype or 1,
-        time = time or os.time() - os.time({year=2000, day=1, month=1, hour=0, min=0, sec=0}),
+        time = time or os.time() - DHCP6_EPOCH,
         mac = mac,
       }
       setmetatable(o, self)
@@ -131,7 +132,7 @@ DHCP6.Option = {
       end
       opt.hwtype, opt.time = string.unpack(">I2I4", data, pos)
       opt.mac = data:sub(pos)
-      opt.time = opt.time + os.time({year=2000, day=1, month=1, hour=0, min=0, sec=0})
+      opt.time = opt.time + DHCP6_EPOCH
       return opt
     end,
 
diff --git a/nselib/http.lua b/nselib/http.lua
index 52852a76d..e6936ea9c 100644
--- a/nselib/http.lua
+++ b/nselib/http.lua
@@ -1034,19 +1034,19 @@ local function cmp_last_used (r1, r2)
       return (r1.last_used or 0) < (r2.last_used or 0);
 end
 
+local arg_max_cache_size = tonumber(stdnse.get_script_args({'http.max-cache-size', 'http-max-cache-size'}) or 1e6);
 local function check_size (cache)
-  local max_size = tonumber(stdnse.get_script_args({'http.max-cache-size', 'http-max-cache-size'}) or 1e6);
 
   local size = cache.size;
 
-  if size > max_size then
+  if size > arg_max_cache_size then
     stdnse.debug1(
         "Current http cache size (%d bytes) exceeds max size of %d",
-        size, max_size);
+        size, arg_max_cache_size);
     table.sort(cache, cmp_last_used);
 
     for i, record in ipairs(cache) do
-      if size <= max_size then break end
+      if size <= arg_max_cache_size then break end
       local result = record.result;
       if type(result.body) == "string" then
         size = size - record.size;
@@ -1056,7 +1056,7 @@ local function check_size (cache)
     cache.size = size;
   end
   stdnse.debug2("Final http cache size (%d bytes) of max size of %d",
-      size, max_size);
+      size, arg_max_cache_size);
   return size;
 end