mercurial/txnutil.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Mon, 18 Nov 2019 09:38:40 +0100
branchstable
changeset 44169 5fd43c788943
parent 43077 687b865b95ad
child 45957 89a2afe31e82
permissions -rw-r--r--
heptapod-ci: also run the dedicated rust test for the rust code The Rust code has various standard rust test that are fast to run. So let's run them. Differential Revision: https://phab.mercurial-scm.org/D8014

# 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(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 IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
    return (vfs(filename, **kwargs), False)