contrib/genosxversion.py

rust-changelog: introducing an intermediate `ChangelogEntry`

Before this change, client code needing to extract, e.g, the Node ID and the
description from a changeset had no other choice than calling both
`entry_for_rev()` and `data_for_rev()`. This duplicates some (limited) computation, and
more importantly imposes bad hygiene for client code: at some point of developement,
the client code would have to pass over both entry and data in its internal layers,
which at some point of development would raise the question whether they are consistent.

We introduce the intermediate `ChangelogEntry` from which both conversion to the generic
`RevlogEntry` and extraction of `ChangelogRevisionData` are possible.
It might grow some convenience methods in the future.

We keep the `data_for_rev()` method of `Changelog` for compatibility, pointing users at the more
powerful alternative.

#!/usr/bin/env python2

import argparse
import os
import subprocess
import sys

try:
    # Always load hg libraries from the hg we can find on $PATH.
    hglib = subprocess.check_output(['hg', 'debuginstall', '-T', '{hgmodules}'])
    sys.path.insert(0, os.path.dirname(hglib))
except subprocess.CalledProcessError:
    # We're probably running with a PyOxidized Mercurial, so just
    # proceed and hope it works out okay.
    pass

from mercurial import util

ap = argparse.ArgumentParser()
ap.add_argument(
    '--paranoid',
    action='store_true',
    help=(
        "Be paranoid about how version numbers compare and "
        "produce something that's more likely to sort "
        "reasonably."
    ),
)
ap.add_argument('--selftest', action='store_true', help='Run self-tests.')
ap.add_argument('versionfile', help='Path to a valid mercurial __version__.py')


def paranoidver(ver):
    """Given an hg version produce something that distutils can sort.

    Some Mac package management systems use distutils code in order to
    figure out upgrades, which makes life difficult. The test case is
    a reduced version of code in the Munki tool used by some large
    organizations to centrally manage OS X packages, which is what
    inspired this kludge.

    >>> paranoidver('3.4')
    '3.4.0'
    >>> paranoidver('3.4.2')
    '3.4.2'
    >>> paranoidver('3.0-rc+10')
    '2.9.9999-rc+10'
    >>> paranoidver('4.2+483-5d44d7d4076e')
    '4.2.0+483-5d44d7d4076e'
    >>> paranoidver('4.2.1+598-48d1e1214d8c')
    '4.2.1+598-48d1e1214d8c'
    >>> paranoidver('4.3-rc')
    '4.2.9999-rc'
    >>> paranoidver('4.3')
    '4.3.0'
    >>> from distutils import version
    >>> class LossyPaddedVersion(version.LooseVersion):
    ...     '''Subclass version.LooseVersion to compare things like
    ...     "10.6" and "10.6.0" as equal'''
    ...     def __init__(self, s):
    ...             self.parse(s)
    ...
    ...     def _pad(self, version_list, max_length):
    ...         'Pad a version list by adding extra 0 components to the end'
    ...         # copy the version_list so we don't modify it
    ...         cmp_list = list(version_list)
    ...         while len(cmp_list) < max_length:
    ...             cmp_list.append(0)
    ...         return cmp_list
    ...
    ...     def __cmp__(self, other):
    ...         if isinstance(other, str):
    ...             other = MunkiLooseVersion(other)
    ...         max_length = max(len(self.version), len(other.version))
    ...         self_cmp_version = self._pad(self.version, max_length)
    ...         other_cmp_version = self._pad(other.version, max_length)
    ...         return cmp(self_cmp_version, other_cmp_version)
    >>> def testver(older, newer):
    ...   o = LossyPaddedVersion(paranoidver(older))
    ...   n = LossyPaddedVersion(paranoidver(newer))
    ...   return o < n
    >>> testver('3.4', '3.5')
    True
    >>> testver('3.4.0', '3.5-rc')
    True
    >>> testver('3.4-rc', '3.5')
    True
    >>> testver('3.4-rc+10-deadbeef', '3.5')
    True
    >>> testver('3.4.2', '3.5-rc')
    True
    >>> testver('3.4.2', '3.5-rc+10-deadbeef')
    True
    >>> testver('4.2+483-5d44d7d4076e', '4.2.1+598-48d1e1214d8c')
    True
    >>> testver('4.3-rc', '4.3')
    True
    >>> testver('4.3', '4.3-rc')
    False
    """
    major, minor, micro, extra = util.versiontuple(ver, n=4)
    if micro is None:
        micro = 0
    if extra:
        if extra.startswith('rc'):
            if minor == 0:
                major -= 1
                minor = 9
            else:
                minor -= 1
            micro = 9999
            extra = '-' + extra
        else:
            extra = '+' + extra
    else:
        extra = ''
    return '%d.%d.%d%s' % (major, minor, micro, extra)


def main(argv):
    opts = ap.parse_args(argv[1:])
    if opts.selftest:
        import doctest

        doctest.testmod()
        return
    with open(opts.versionfile) as f:
        for l in f:
            if l.startswith('version = b'):
                # version number is entire line minus the quotes
                ver = l[len('version = b') + 1 : -2]
                break
    if opts.paranoid:
        print(paranoidver(ver))
    else:
        print(ver)


if __name__ == '__main__':
    main(sys.argv)