gistfile1.lua

--
-- expire record and memcached record
-- 
require('Memcached') -- http://luamemcached.luaforge.net/

-- http://mixi.jp/view_bbs.pl?id=33263045&comm_id=3528783 #20
connect_memcache()

function expire()
   local args = {}
   local cdate = string.format("%d", _time())
   table.insert(args, "addcond\0exptime\0NUMLE\0" .. cdate)
   
   local res = _misc("search", args)
   if res then
      for i = 1, #res do
	 local row = _get(res[i])
	 local user_id = get_rdb_value(_get(res[i]), 'user_id')
	 if user_id then
	    expire_user_cache(user_id)
	 end
	 _out(res[i])
      end
   else
      _log("expiration was failed")
   end
end

function get_rdb_value(row, key)
   local escaped_key = key:gsub("%%","%%%%")
   local s,e,result = string.find("\000"..row.."\000", "%z"..escaped_key.."%z([^%z]*)%z")
   return(result)
end

function expire_user_cache(user_id)
   if memcache == nil then
      connect_memcache()
   end
   _log("expire user cache: " .. user_id, 0)
   if not pcall(function(user_id)
		   memcache:delete("mailfeeds:user_feed:" .. user_id)
		   -- and more...
		end, user_id) then
      memcache = nil
   end
end

function connect_memcache()
   if pcall(function()
	       memcache = Memcached.Connect('localhost', 11211)
	    end) then
      _log("connecet_memcache: Success")
   else
      memcache = nil
      _log("connecet_memcache: Failure")
   end
end