Mercurial > hg
view mercurial/dirstateguard.py @ 39494:e72130f58f5d
snapshot: consider all snapshots in the parents' chains
There are no reasons to only consider full snapshot as a possible base for an
intermediate snapshot. Now that the basic principles have been set, we can
start adding more levels of snapshots.
We now consider all snapshots in the parent's chains (full or intermediate).
This creates a chain of intermediate snapshots, each smaller than the previous
one.
# Effect On The Test Repository
In the test repository, we can see a decrease in the revlog size and slightly
shorter delta chain.
However, that approach creates snapshots more frequently, increasing the risk
of ending into problematic cases in very branchy repositories (not triggered
by the test repository). The next changesets will remove that risk by adding
logic that increases deltas reuse.
author | Boris Feld <boris.feld@octobus.net> |
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date | Fri, 07 Sep 2018 11:17:30 -0400 |
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()