Mercurial > hg
view mercurial/dirstateguard.py @ 39016:39b8277e2115
changegroup: differentiate between fulltext and diff based deltas
Previously, revisiondelta encoded a delta and an optional prefix
containing a delta header. The underlying code could populate
the delta with either a real delta or a fulltext revision.
Following the theme of wanting to defer serialization of revision
data to the changegroup format as long as possible, it seems
prudent for the revision delta instance to capture what type of
data is being represented. This could possibly allow us to
encode revision data differently in the future. But for the
short term, it makes the behavior of a revisiondelta more
explicit.
Differential Revision: https://phab.mercurial-scm.org/D4213
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Wed, 08 Aug 2018 16:01:26 -0700 |
parents | ad24b581e4d9 |
children | b74481038438 |
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# 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 = 'dirstate.backup.%s.%d' % (name, id(self)) self._narrowspecbackupname = ('narrowspec.backup.%s.%d' % (name, id(self))) repo.dirstate.savebackup(repo.currenttransaction(), self._backupname) narrowspec.savebackup(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 = (_("can't close already inactivated backup: %s") % self._backupname) raise error.Abort(msg) self._repo.dirstate.clearbackup(self._repo.currenttransaction(), self._backupname) narrowspec.clearbackup(self._repo, self._narrowspecbackupname) self._active = False self._closed = True def _abort(self): narrowspec.restorebackup(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 = (_("can't release already inactivated backup: %s") % self._backupname) raise error.Abort(msg) self._abort()