X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Ftag.cpp;h=3586507a5f8ba17c35a560b55fdbfb6990290672;hp=c8041e0d0331c8c20fc7f78a657b39d651e5daab;hb=b617c5d7b5283ad260a77f01e42e6170cabbc03d;hpb=c6aea1bc1586ffef132e6fffdf99343cb56617db

diff --git a/source/tag.cpp b/source/tag.cpp
index c8041e0d..3586507a 100644
--- a/source/tag.cpp
+++ b/source/tag.cpp
@@ -1,21 +1,35 @@
+/* $Id$
+
+This file is part of libmspgl
+Copyright © 2007, 2010  Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
 #include "tag.h"
 
+namespace {
+
+template<typename T>
+inline unsigned hash(T begin, T end)
+{
+	unsigned result = 0;
+	for(T i=begin; (i!=end && *i); ++i)
+		result = ((result>>29)|(result<<5))^static_cast<unsigned char>(*i);
+	return result;
+}
+
+}
+
 namespace Msp {
 namespace GL {
 
 Tag::Tag(const char *s):
-	id(0)
-{
-	for(const char *i=s; *i; ++i)
-		id=id*id+*i;
-}
+	id(s ? hash<const char *>(s, 0) : 0)
+{ }
 
 Tag::Tag(const std::string &s):
-	id(0)
-{
-	for(std::string::const_iterator i=s.begin(); i!=s.end(); ++i)
-		id=id*id+*i;
-}
+	id(hash(s.begin(), s.end()))
+{ }
 
 } // namespace GL
 } // namespace Msp