optimized version of "str2seconds" with pre-compiled regexp;

fail2ban/server/mytime.py

@@ -98,6 +98,25 @@ class MyTime:
 		else:
 			return time.localtime(MyTime.myTime)
 
+	## precreate/precompile primitives used in str2seconds:
+
+	## preparing expression:
+	_str2sec_prep = re.compile(r"(?i)(?<=[a-z])(\d)")
+	## finally expression:
+	_str2sec_fini = re.compile(r"(\d)\s+(\d)")
+	## wrapper for each sub part:
+	_str2sec_subpart = r"(?i)(?<=[\d\s])(%s)\b"
+	## parts to be replaced - pair of (regexp x replacement):
+	_str2sec_parts = (
+		(re.compile(_str2sec_subpart % r"days?|da|dd?"),      "*"+str(24*60*60)),
+		(re.compile(_str2sec_subpart % r"weeks?|wee?|ww?"),   "*"+str(7*24*60*60)),
+		(re.compile(_str2sec_subpart % r"months?|mon?"),      "*"+str((365*3+366)*24*60*60/4/12)),
+		(re.compile(_str2sec_subpart % r"years?|yea?|yy?"),   "*"+str((365*3+366)*24*60*60/4)),
+		(re.compile(_str2sec_subpart % r"seconds?|sec?|ss?"), "*"+str(1)),
+		(re.compile(_str2sec_subpart % r"minutes?|min?|mm?"), "*"+str(60)),
+		(re.compile(_str2sec_subpart % r"hours?|hou?|hh?"),   "*"+str(60*60)),
+	)
+
 	@staticmethod
 	def str2seconds(val):
 		"""Wraps string expression like "1h 2m 3s" into number contains seconds (3723).
@@ -120,13 +139,9 @@ class MyTime:
 		if isinstance(val, (int, long, float, complex)):
 			return val
 		# replace together standing abbreviations, example '1d12h' -> '1d 12h':
-		val = re.sub(r"(?i)(?<=[a-z])(\d)", r" \1", val)
+		val = MyTime._str2sec_prep.sub(r" \1", val)
 		# replace abbreviation with expression:
-		for rexp, rpl in (
-			(r"days?|da|dd?", 24*60*60), (r"weeks?|wee?|ww?", 7*24*60*60), (r"months?|mon?", (365*3+366)*24*60*60/4/12), 
-			(r"years?|yea?|yy?", (365*3+366)*24*60*60/4), 
-			(r"seconds?|sec?|ss?", 1), (r"minutes?|min?|mm?", 60), (r"hours?|hou?|hh?", 60*60),
-		):
-			val = re.sub(r"(?i)(?<=[\d\s])(%s)\b" % rexp, "*"+str(rpl), val)
-		val = re.sub(r"(\d)\s+(\d)", r"\1+\2", val);
+		for rexp, rpl in MyTime._str2sec_parts:
+			val = rexp.sub(rpl, val)
+		val = MyTime._str2sec_fini.sub(r"\1+\2", val)
 		return eval(val)