modules/luci-base/luasrc/ccache.lua

   1 -- Copyright 2008 Steven Barth <steven@midlink.org>
   2 -- Copyright 2008 Jo-Philipp Wich <xm@leipzig.freifunk.net>
   3 -- Licensed to the public under the Apache License 2.0.
   4
   5 local io = require "io"
   6 local fs = require "nixio.fs"
   7 local util = require "luci.util"
   8 local nixio = require "nixio"
   9 local debug = require "debug"
  10 local string = require "string"
  11 local package = require "package"
  12
  13 local type, loadfile = type, loadfile
  14
  15
  16 module "luci.ccache"
  17
  18 function cache_ondemand(...)
  19         if debug.getinfo(1, 'S').source ~= "=?" then
  20                 cache_enable(...)
  21         end
  22 end
  23
  24 function cache_enable(cachepath, mode)
  25         cachepath = cachepath or "/tmp/luci-modulecache"
  26         mode = mode or "r--r--r--"
  27
  28         local loader = package.loaders[2]
  29         local uid    = nixio.getuid()
  30
  31         if not fs.stat(cachepath) then
  32                 fs.mkdir(cachepath)
  33         end
  34
  35         local function _encode_filename(name)
  36                 local encoded = ""
  37                 for i=1, #name do
  38                         encoded = encoded .. ("%2X" % string.byte(name, i))
  39                 end
  40                 return encoded
  41         end
  42
  43         local function _load_sane(file)
  44                 local stat = fs.stat(file)
  45                 if stat and stat.uid == uid and stat.modestr == mode then
  46                         return loadfile(file)
  47                 end
  48         end
  49
  50         local function _write_sane(file, func)
  51                 if nixio.getuid() == uid then
  52                         local fp = io.open(file, "w")
  53                         if fp then
  54                                 fp:write(util.get_bytecode(func))
  55                                 fp:close()
  56                                 fs.chmod(file, mode)
  57                         end
  58                 end
  59         end
  60
  61         package.loaders[2] = function(mod)
  62                 local encoded = cachepath .. "/" .. _encode_filename(mod)
  63                 local modcons = _load_sane(encoded)
  64
  65                 if modcons then
  66                         return modcons
  67                 end
  68
  69                 -- No cachefile
  70                 modcons = loader(mod)
  71                 if type(modcons) == "function" then
  72                         _write_sane(encoded, modcons)
  73                 end
  74                 return modcons
  75         end
  76 end