git_remote_helpers/fastimport/dates.py

   1 # Copyright (C) 2008 Canonical Ltd
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program; if not, write to the Free Software
  15 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16
  17 """Date parsing routines.
  18
  19 Each routine returns timestamp,timezone where
  20
  21 * timestamp is seconds since epoch
  22 * timezone is the offset from UTC in seconds.
  23 """
  24
  25
  26 import time
  27
  28 from git_remote_helpers.fastimport import errors
  29
  30
  31 def parse_raw(s, lineno=0):
  32     """Parse a date from a raw string.
  33
  34     The format must be exactly "seconds-since-epoch offset-utc".
  35     See the spec for details.
  36     """
  37     timestamp_str, timezone_str = s.split(' ', 1)
  38     timestamp = float(timestamp_str)
  39     timezone = _parse_tz(timezone_str, lineno)
  40     return timestamp, timezone
  41
  42
  43 def _parse_tz(tz, lineno):
  44     """Parse a timezone specification in the [+|-]HHMM format.
  45
  46     :return: the timezone offset in seconds.
  47     """
  48     # from git_repository.py in bzr-git
  49     if len(tz) != 5:
  50         raise errors.InvalidTimezone(lineno, tz)
  51     sign = {'+': +1, '-': -1}[tz[0]]
  52     hours = int(tz[1:3])
  53     minutes = int(tz[3:])
  54     return sign * 60 * (60 * hours + minutes)
  55
  56
  57 def parse_rfc2822(s, lineno=0):
  58     """Parse a date from a rfc2822 string.
  59
  60     See the spec for details.
  61     """
  62     raise NotImplementedError(parse_rfc2822)
  63
  64
  65 def parse_now(s, lineno=0):
  66     """Parse a date from a string.
  67
  68     The format must be exactly "now".
  69     See the spec for details.
  70     """
  71     return time.time(), 0
  72
  73
  74 # Lookup tabel of date parsing routines
  75 DATE_PARSERS_BY_NAME = {
  76     'raw':      parse_raw,
  77     'rfc2822':  parse_rfc2822,
  78     'now':      parse_now,
  79     }