view mercurial/txnutil.py @ 32267:c2380b448265

caches: move the 'updating the branch cache' message in 'updatecaches'

We are about to remove the branchmap cache update in changegroup application.
There is a debug message alongside this update that we do not want to loose. We
move the message beforehand to simplify the test update in the next changeset.
The message move is quite noisy and isolating that noise is useful.

Most tests update are just line reordering since the message is issued at a
later point during the transaction.

After this changes, the message is displayed in more case since local commit
creation also issue it.

# txnutil.py - transaction related utilities
#
#  Copyright FUJIWARA Katsunori <[e-mail]> 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)