In movefile mtime preservation code, simply round down to the nearest whole

second since python's float cannot preserve the st_mtim.tv_nsec field with
complete precision. Note that we have to use stat_obj[stat.ST_MTIME] here
because the float stat_obj.st_mtime rounds *up* sometimes.

svn path=/main/trunk/; revision=15054

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index 5be9a50d3310ef3bb8b637568ae211d9a5c1b421..69533c7c039d864c87c9e08e21ce3b30067942f8 100644 (file)
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -7657,37 +7657,17 @@ def movefile(src, dest, newmtime=None, sstat=None, mysettings=None,
                        if newmtime is not None:
                                os.utime(dest, (newmtime, newmtime))
                        else:
+                               newmtime = sstat[stat.ST_MTIME]
                                if renamefailed:
-                                       # If rename succeeded then this is not necessary, since
-                                       # rename automatically preserves timestamps with complete
-                                       # precision.
-                                       if sstat[stat.ST_MTIME] == long(sstat.st_mtime):
-                                               newmtime = sstat.st_mtime
-                                       else:
-                                               # Prevent mtime from rounding up to the next second.
-                                               # Generate nanosecond resolution (9 decimal places) in
-                                               # order to ensure that the floating point representation
-                                               # is the highest value possible without rounding up.
-                                               int_mtime = sstat[stat.ST_MTIME]
-                                               mtime_str = "%i." % int_mtime
-                                               nonzero_digits = 0
-                                               decimal_places = 9
-                                               for i in range(decimal_places):
-                                                       for digit in range(9, -1, -1):
-                                                               digit_str = str(digit)
-                                                               if int_mtime == long(float(mtime_str + digit_str)):
-                                                                       break
-                                                       if digit > 0:
-                                                               nonzero_digits += 1
-                                                       mtime_str += digit_str
-
-                                               if nonzero_digits > 0:
-                                                       newmtime = float(mtime_str)
-                                               else:
-                                                       newmtime = int_mtime
-
+                                       # If rename succeeded then timestamps are automatically
+                                       # preserved with complete precision because the source
+                                       # and destination inode are the same. Otherwise, round
+                                       # down to the nearest whole second since python's float
+                                       # st_mtime cannot be used to preserve the st_mtim.tv_nsec
+                                       # field with complete precision. Note that we have to use
+                                       # stat_obj[stat.ST_MTIME] here because the float
+                                       # stat_obj.st_mtime rounds *up* sometimes.
                                        os.utime(dest, (newmtime, newmtime))
-                               newmtime = sstat[stat.ST_MTIME]
        except OSError:
                # The utime can fail here with EPERM even though the move succeeded.
                # Instead of failing, use stat to return the mtime if possible.