cvs2svn_lib/time_range.py

   1 # (Be in -*- python -*- mode.)
   2 #
   3 # ====================================================================
   4 # Copyright (c) 2006-2008 CollabNet.  All rights reserved.
   5 #
   6 # This software is licensed as described in the file COPYING, which
   7 # you should have received as part of this distribution.  The terms
   8 # are also available at http://subversion.tigris.org/license-1.html.
   9 # If newer versions of this license are posted there, you may use a
  10 # newer version instead, at your option.
  11 #
  12 # This software consists of voluntary contributions made by many
  13 # individuals.  For exact contribution history, see the revision
  14 # history and logs, available at http://cvs2svn.tigris.org/.
  15 # ====================================================================
  16
  17 """This module contains a class to manage time ranges."""
  18
  19
  20 class TimeRange(object):
  21   __slots__ = ('t_min', 't_max')
  22
  23   def __init__(self):
  24     # Start out with a t_min higher than any incoming time T, and a
  25     # t_max lower than any incoming T.  This way the first T will push
  26     # t_min down to T, and t_max up to T, naturally (without any
  27     # special-casing), and successive times will then ratchet them
  28     # outward as appropriate.
  29     self.t_min = 1L<<32
  30     self.t_max = 0
  31
  32   def add(self, timestamp):
  33     """Expand the range to encompass TIMESTAMP."""
  34
  35     if timestamp < self.t_min:
  36       self.t_min = timestamp
  37     if timestamp > self.t_max:
  38       self.t_max = timestamp
  39
  40   def __cmp__(self, other):
  41     # Sorted by t_max, and break ties using t_min.
  42     return cmp(self.t_max, other.t_max) or cmp(self.t_min, other.t_min)
  43
  44   def __lt__(self, other):
  45     c = cmp(self.t_max, other.t_max)
  46     if 0 == c:
  47       return self.t_min < other.t_min
  48     return c < 0
  49
  50