manifest: tigher manifest parsing and flag use
In the manifest line, flags are put directly after the hash, so the
parser has been guessing the presence of flags based on the length of
the hash. Replace this assumption by an enumeration of the valid flags
and removing them from the hash first as they are distinct input values.
Consistently handle the expected 256bit length of the SHA1-replacement
in the pure Python parser. Check that setting flags will use one of the
blessed values.
Extend write logic in the C version to handle 256bit hashes as well.
Verify that hashes always have exactly the expected length. Since
1070df141718 we should no longer depend on the old extra-byte hack.
Differential Revision: https://phab.mercurial-scm.org/D8679
# dirstateguard.py - class to allow restoring dirstate after failure
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# 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
from .i18n import _
from . import (
error,
narrowspec,
util,
)
class dirstateguard(util.transactional):
'''Restore dirstate at unexpected failure.
At the construction, this class does:
- write current ``repo.dirstate`` out, and
- save ``.hg/dirstate`` into the backup file
This restores ``.hg/dirstate`` from backup file, if ``release()``
is invoked before ``close()``.
This just removes the backup file at ``close()`` before ``release()``.
'''
def __init__(self, repo, name):
self._repo = repo
self._active = False
self._closed = False
self._backupname = b'dirstate.backup.%s.%d' % (name, id(self))
self._narrowspecbackupname = b'narrowspec.backup.%s.%d' % (
name,
id(self),
)
repo.dirstate.savebackup(repo.currenttransaction(), self._backupname)
narrowspec.savewcbackup(repo, self._narrowspecbackupname)
self._active = True
def __del__(self):
if self._active: # still active
# this may occur, even if this class is used correctly:
# for example, releasing other resources like transaction
# may raise exception before ``dirstateguard.release`` in
# ``release(tr, ....)``.
self._abort()
def close(self):
if not self._active: # already inactivated
msg = (
_(b"can't close already inactivated backup: %s")
% self._backupname
)
raise error.Abort(msg)
self._repo.dirstate.clearbackup(
self._repo.currenttransaction(), self._backupname
)
narrowspec.clearwcbackup(self._repo, self._narrowspecbackupname)
self._active = False
self._closed = True
def _abort(self):
narrowspec.restorewcbackup(self._repo, self._narrowspecbackupname)
self._repo.dirstate.restorebackup(
self._repo.currenttransaction(), self._backupname
)
self._active = False
def release(self):
if not self._closed:
if not self._active: # already inactivated
msg = (
_(b"can't release already inactivated backup: %s")
% self._backupname
)
raise error.Abort(msg)
self._abort()