mercurial/txnutil.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Tue, 13 Dec 2022 09:59:22 +0100
changeset 50057 cf8b9c80d67c
parent 49306 2e726c934fcd
child 51863 f4733654f144
permissions -rw-r--r--
dirstate: issue a developer warning on implicit write on wlock release Our goal is to get rid of all these to clarify the writing pattern, so it is time to warn about this (and later, forbid it).

# 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 . import encoding


def mayhavepending(root):
    """return whether 'root' may have pending changes, which are
    visible to this process.
    """
    return root == encoding.environ.get(b'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(b'%s.pending' % filename, **kwargs), True)
        except FileNotFoundError:
            pass
    return (vfs(filename, **kwargs), False)