Sleep between thoughts when connecting to avoid eating CPU

Generate a new nickname when it is in use or erroneous and check the...

doc/irc.luadoc

@@ -25,9 +25,8 @@
 module "irc"
 
 --- Create a new IRC object. Use <code>irc:connect</code> to connect to a server.
--- @param user Table with fields <code>nick</code>, <code>username</code>, <code>realname</code>, and <code>nick_generator</code>.
+-- @param user Table with fields <code>nick</code>, <code>username</code> and <code>realname</code>.
 -- The <code>nick</code> field is required.
--- The <code>nick_generator</code> field is a fuction that should return a new nick name given the old one.
 --
 -- @return Returns a new <code>irc</code> object.
 function new(user)

handlers.lua

@@ -74,7 +74,21 @@ handlers["NICK"] = function(o, prefix, newnick)
 	else
 		o:invoke("NickChange", user, newnick)
 	end
+	if user.nick == o.nick then
+		o.nick = newnick
 	end
+end
+
+local function needNewNick(o, prefix, target, badnick)
+	local newnick = o.nickGenerator(badnick)
+	o:send("NICK %s", newnick)
+end
+
+-- ERR_ERRONEUSNICKNAME (Misspelt but remains for historical reasons)
+handlers["432"] = needNewNick
+
+-- ERR_NICKNAMEINUSE
+handlers["433"] = needNewNick
 
 --NAMES list
 handlers["353"] = function(o, prefix, me, chanType, channel, names)
@@ -96,18 +110,6 @@ handlers["366"] = function(o, prefix, me, channel, msg)
 	end
 end
 
-local function handle_bad_nick(o, prefix, x, badnick)
-	o.nick = o.nick_generator(badnick)
-	o.send("NICK %s", o.nick)
-	o.send("USER %s 0 * :%s", o.username, o.realname)
-end
-
--- ERR_ERRONEOUSNICKNAME
-handlers["432"] = handle_bad_nick
-
--- ERR_NICKNAMEINUSE
-handlers["433"] = handle_bad_nick
-
 --no topic
 handlers["331"] = function(o, prefix, me, channel)
 	o:invoke("OnTopic", channel, nil)

init.lua

@@ -31,16 +31,16 @@ function meta_preconnect.__index(o, k)
 	return v
 end
 
-function new(user)
+function new(data)
 	local o = {
-		nick = assert(user.nick, "Field 'nick' is required");
+		nick = assert(data.nick, "Field 'nick' is required");
-		username = user.username or "lua";
+		username = data.username or "lua";
-		realname = user.realname or "Lua owns";
+		realname = data.realname or "Lua owns";
+		nickGenerator = data.nickGenerator or defaultNickGenerator;
 		hooks = {};
 		track_users = true;
-		nick_generator = user.nick_generator or
-				function(oldnick) error("Nick already in use.") end
 	}
+	assert(checkNick(o.nick), "Erroneous nickname passed to irc.new")
 	return setmetatable(o, meta_preconnect)
 end
 
@@ -137,6 +137,7 @@ function meta_preconnect:connect(_host, _port)
 
 	repeat
 		self:think()
+		socket.select(nil, nil, 0.1) -- Sleep so that we don't eat CPU
 	until self.authed
 end
 

util.lua

@@ -1,9 +1,12 @@
 local setmetatable = setmetatable
+local sub = string.sub
+local byte = string.byte
 local char = string.char
 local table = table
 local assert = assert
 local tostring = tostring
 local type = type
+local random = math.random
 
 module "irc"
 
@@ -107,3 +110,27 @@ local underlineByte = char(31)
 function underline(text)
 	return underlineByte..text..underlineByte
 end
+
+function checkNick(nick)
+	return nick:find("^[a-zA-Z_%-%[|%]%^{|}`][a-zA-Z0-9_%-%[|%]%^{|}`]*$") ~= nil
+end
+
+function defaultNickGenerator(nick)
+	-- LuaBot -> LuaCot -> LuaCou -> ...
+	-- We change a random charachter rather than appending to the
+	-- nickname as otherwise the new nick could exceed the ircd's
+	-- maximum nickname length.
+	local randindex = random(1, #nick)
+	local randchar = sub(nick, randindex, randindex)
+	local b = byte(randchar)
+	b = b + 1
+	if b < 65 or b > 125 then
+		b = 65
+	end
+	-- Get the halves before and after the changed character
+	local first = sub(nick, 1, randindex - 1)
+	local last = sub(nick, randindex + 1, #nick)
+	nick = first..char(b)..last  -- Insert the new charachter
+	return nick
+end
+