dirstate-v2: no longer register the data-file during transaction
If the data file change during the transaction, we cannot truncate it.
The content of the file itself is fine as it will get backed up at the same time
as the docket.
Leaving the trailing data at the end of failed transaction is fine. The
dirstate-v2 format supports it. The dead data will simply we written over if
necessary.
# 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)