simple 1v1 chat; thread-safe persistent db; remove levenshtein; cleanup

common.py

@@ -32,36 +32,21 @@ def logger(severity, message):
 	sys.stderr.write('%s %s %s: %s\n' % args)
 
 def conf_save(obj):
+	if conf('persistent_locked'):
+		return False
+
+	set_conf('persistent_locked', True)
+
 	with open(conf('persistent_storage'), 'wb') as fd:
 		return pickle.dump(obj, fd)
 
+	set_conf('persistent_locked', False)
+
 def conf_load():
 	with open(conf('persistent_storage'), 'rb') as fd:
 		fd.seek(0)
 		return pickle.load(fd)
 
-def levenshtein(a, b, return_table=False):
-	'''returns the levenshtein distance between a and b'''
-	# initialisize a table with 0, but the 0-rows/cols with their index
-	d = [[(i if 0 == j else j if 0 == i else 0) for j in range(len(b)+1)] for i in range(len(a)+1)]
-
-	i = j = 0
-	for i in range(1, len(a)+1):
-		for j in range(1, len(b)+1):
-			if a[i-1] == b[j-1]:
-				d[i][j] = d[i-1][j-1]
-			else:
-				d[i][j] = min(
-					d[i-1][j] + 1,    # deletion
-					d[i][j-1] + 1,    # insertion
-					d[i-1][j-1] + 1,  # substitution
-				)
-
-	if return_table:
-		return (d, d[i][j])
-	else:
-		return d[i][j]
-
 def get_version_git():
 	import subprocess