view tests/readlink.py @ 32285:fe3105e6e051

shelve: make shelvestate use simplekeyvaluefile

Currently shelvestate uses line ordering to differentiate fields. This
makes it hard for extensions to wrap shelve, since if two alternative
versions of code add a new line, correct merging is going to be problematic.
simplekeyvaluefile was introduced fot this purpose specifically.

After this patch:
- shelve will always write a simplekeyvaluefile
- unshelve will check the first line of the file for a version, and if the
  version is 1, will read it in a position-based way, if the version is 2,
  will read it in a key-value way

As discussed with Yuya previously, this will be able to handle old-style
shelvedstate files, but old Mercurial versions will fail on the attempt to
read shelvedstate file of version 2 with a self-explanatory message:
  'abort: this version of shelve is incompatible with the version used
  in this repo'

#!/usr/bin/env python

from __future__ import absolute_import, print_function

import errno
import os
import sys

for f in sys.argv[1:]:
    try:
        print(f, '->', os.readlink(f))
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print(f, '->', f, 'not a symlink')

sys.exit(0)