Fixed python 3 performance regression

It makes the difference between tests in 110s, or 11s

Author: Byron

doc/source/changes.rst

@@ -2,6 +2,11 @@
 Changelog
 #########
 
+**********
+v0.8.4
+**********
+- Fixed Python 3 performance regression
+
 **********
 v0.8.3
 **********

smmap/__init__.py

@@ -3,7 +3,7 @@
 __author__ = "Sebastian Thiel"
 __contact__ = "[email protected]"
 __homepage__ = "https://github.com/Byron/smmap"
-version_info = (0, 8, 3)
+version_info = (0, 8, 4)
 __version__ = '.'.join(str(i) for i in version_info)
 
 # make everything available in root package for convenience

smmap/util.py

@@ -23,9 +23,10 @@
 except NameError:
     # Python 3 has no `buffer`; only `memoryview`
     def buffer(obj, offset, size):
-        # return memoryview(obj)[offset:offset+size]
+        # Actually, for gitpython this is fastest ... .
+        return memoryview(obj)[offset:offset+size]
         # doing it directly is much faster !
-        return obj[offset:offset + size]
+        # return obj[offset:offset + size]
 
 
 def string_types():