'Retrieve the directory revision informatino using svnversion'

def get_revision(self):

    (code, data) = _run_command(['svnversion', '-c', self.path])
    if code:
        log.warn('svnversion    failed')
        return 0
    parsed = self.revision_re.match(data)
    if parsed:
        return int(parsed.group(2))
    else:
        return 0
