Mercurial > hg
view mercurial/txnutil.py @ 32270:218ca8526ec0
scmutil: make simplekeyvaluefile able to have a non-key-value first line
To ease migration from files with version numbers in their first lines,
we want simplekeyvaluefile to support a non-key-value first line. In this
way, old versions of Mercurial will read such files, discover a newer version
than the one they know how to handle and fail gracefully, rather than with
exception. Shelve's shelvestate file is an example.
author | Kostia Balytskyi <ikostia@fb.com> |
---|---|
date | Thu, 11 May 2017 08:49:33 -0700 |
parents | 206532700213 |
children | 2372284d9457 |
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# txnutil.py - transaction related utilities # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import errno from . import ( encoding, ) def mayhavepending(root): '''return whether 'root' may have pending changes, which are visible to this process. ''' return root == encoding.environ.get('HG_PENDING') def trypending(root, vfs, filename, **kwargs): '''Open file to be read according to HG_PENDING environment variable This opens '.pending' of specified 'filename' only when HG_PENDING is equal to 'root'. This returns '(fp, is_pending_opened)' tuple. ''' if mayhavepending(root): try: return (vfs('%s.pending' % filename, **kwargs), True) except IOError as inst: if inst.errno != errno.ENOENT: raise return (vfs(filename, **kwargs), False)