From: brain <brain@e03df62e-2008-0410-955e-edbf42e46eb7>
Date: Thu, 23 Aug 2007 16:35:59 +0000 (+0000)
Subject: Switch around the two operations in MatchCIDRBits to make negative matches faster... 
X-Git-Tag: v2.0.23~4760
X-Git-Url: https://git.netwichtig.de/gitweb/?a=commitdiff_plain;h=8214184319ccd044376cb2a9a30518c9bfeebab3;hp=05716503f30bbb386b3e98e4e22ce232eae570d9;p=user%2Fhenk%2Fcode%2Finspircd.git

Switch around the two operations in MatchCIDRBits to make negative matches faster (and not change the speed of positive matches)


git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@7797 e03df62e-2008-0410-955e-edbf42e46eb7
---

diff --git a/src/socket.cpp b/src/socket.cpp
index b28414d4a..976c0585b 100644
--- a/src/socket.cpp
+++ b/src/socket.cpp
@@ -133,19 +133,19 @@ void ListenSocket::HandleEvent(EventType et, int errornum)
 /* Match raw bytes using CIDR bit matching, used by higher level MatchCIDR() */
 bool irc::sockets::MatchCIDRBits(unsigned char* address, unsigned char* mask, unsigned int mask_bits)
 {
-	unsigned int modulus = mask_bits % 8; /* Number of whole bytes in the mask */
-	unsigned int divisor = mask_bits / 8; /* Remaining bits in the mask after whole bytes are dealt with */
+	unsigned int divisor = mask_bits / 8; /* Number of whole bytes in the mask */
+	unsigned int modulus = mask_bits % 8; /* Remaining bits in the mask after whole bytes are dealt with */
 
-	/* First compare the whole bytes, if they dont match, return false */
-	if (memcmp(address, mask, divisor))
-		return false;
-
-	/* Now if there are any remainder bits, we compare them with logic AND */
+	/* First (this is faster) compare the odd bits with logic ops */
 	if (modulus)
 		if ((address[divisor] & inverted_bits[modulus]) != (mask[divisor] & inverted_bits[modulus]))
 			/* If they dont match, return false */
 			return false;
 
+	/* Secondly (this is slower) compare the whole bytes */
+	if (memcmp(address, mask, divisor))
+		return false;
+
 	/* The address matches the mask, to mask_bits bits of mask */
 	return true;
 }