Use a WORKING TS6 UID generator, adapted from InspIRCd source

Closes #21.

protocols/inspircd.py

@@ -8,6 +8,8 @@ from copy import copy
 import traceback
 from classes import *
 
+uidgen = TS6UIDGenerator()
+
 def _sendFromServer(irc, msg):
     irc.send(':%s %s' % (irc.sid, msg))
 
@@ -15,7 +17,7 @@ def _sendFromUser(irc, numeric, msg):
     irc.send(':%s %s' % (numeric, msg))
 
 def spawnClient(irc, nick, ident, host, *args):
-    uid = next_uid(irc.sid)
+    uid = uidgen.next_uid(irc.sid)
     ts = int(time.time())
     if not isNick(nick):
         raise ValueError('Invalid nickname %r.' % nick)

utils.py

@@ -5,17 +5,33 @@ global bot_commands
 # This should be a mapping of command names to functions
 bot_commands = {}
 
-# From http://www.inspircd.org/wiki/Modules/spanningtree/UUIDs.html
-chars = string.ascii_uppercase + string.digits
-iters = [iter(chars) for _ in range(6)]
-uidchars = [next(char) for char in iters]
+class TS6UIDGenerator():
+    """TS6 UID Generator module, adapted from InspIRCd source
+    https://github.com/inspircd/inspircd/blob/f449c6b296ab/src/server.cpp#L85-L156
+    """
 
-def next_uid(sid, level=-1):
-    try:
-        uidchars[level] = next(iters[level])
-        return sid + ''.join(uidchars)
-    except StopIteration:
-        return next_uid(sid, level-1)
+    def __init__(self):
+        # TS6 UIDs are 6 characters in length (9 including the SID).
+        # They wrap from ABCDEFGHIJKLMNOPQRSTUVWXYZ -> 1234567890 -> wrap around:
+        # (e.g. AAAAAA, AAAAAB ..., AAAAA8, AAAAA9, AAAAB0)
+        self.allowedchars = string.ascii_uppercase + string.digits
+        self.uidchars = [self.allowedchars[-1]]*6
+
+    def increment(self, pos=5):
+        # If we're at the last character in the list of allowed ones, reset
+        # and increment the next level above.
+        if self.uidchars[pos] == self.allowedchars[-1]:
+            self.uidchars[pos] = self.allowedchars[0]
+            self.increment(pos-1)
+        else:
+            # Find what position in the allowed characters list we're currently
+            # on, and add one.
+            idx = self.allowedchars.find(self.uidchars[pos])
+            self.uidchars[pos] = self.allowedchars[idx+1]
+
+    def next_uid(self, sid):
+        self.increment()
+        return sid + ''.join(self.uidchars)
 
 def msg(irc, target, text, notice=False):
     command = 'NOTICE' if notice else 'PRIVMSG'