import re
import sha
from datetime import datetime
from time import strptime
PATCH_DATE_FORMAT = '%Y%m%d%H%M%S'
patch_pattern = r"""
\[ # Patch start indicator
(?P<name>[^\n]+)\n # Patch name (rest of same line)
(?P<author>[^\*]+) # Patch author
\* # Author/date separator
(?P<inverted>[-\*]) # Inverted patch indicator
(?P<date>\d{14}) # Patch date
(?:\n(?P<comment>(?:^\ [^\n]*\n)+))? # Optional long comment
\] # Patch end indicator
"""
patch_re = re.compile(patch_pattern, re.VERBOSE | re.MULTILINE)
tidy_comment_re = re.compile(r'^ ', re.MULTILINE)
class Patch:
"""
Patch details, as defined in a darcs inventory file.
Attribute names match those generated by the
``darcs changes --xml-output`` command.
"""
def __init__(self, name, author, date, inverted, comment=None):
self.name = name
self.author = author
self.date = datetime(*strptime(date, PATCH_DATE_FORMAT)[:6])
self.inverted = inverted
self.comment = comment
def __str__(self):
return self.name
@property
def hash(self):
"""
Calculates the filename of the gzipped file containing patch
contents in the repository's ``patches`` directory.
This consists of the patch date, a partial SHA-1 hash of the
patch author and a full SHA-1 hash of the complete patch
details.
"""
date_str = self.date.strftime(PATCH_DATE_FORMAT)
complete_patch_details = '%s%s%s%s%s' % (
self.name, self.author, date_str,
self.comment and ''.join([l.rstrip() for l in self.comment.split('\n')]) or '',
self.inverted and 't' or 'f',
)
return '%s-%s-%s.gz' % (date_str,
sha.new(self.author).hexdigest()[:5],
sha.new(complete_patch_details).hexdigest())
def parse_inventory(inventory):
"""
Given the contents of a darcs inventory file, generates ``Patch``
objects representing contained patch details.
"""
for match in patch_re.finditer(inventory):
attrs = match.groupdict(None)
attrs['inverted'] = (attrs['inverted'] == '-')
if attrs['comment'] is not None:
attrs['comment'] = tidy_comment_re.sub('', attrs['comment']).strip()
yield Patch(**attrs)
if __name__ == '__main__':
import urllib2
inventory = urllib2.urlopen('http://darcs.net/_darcs/inventory').read()
for patch in parse_inventory(inventory):
print patch.__dict__
