upstream/mercurial-mirror Files · mercurial/dirstateguard.py

workingctx: add a way for extensions to run code at status fixup time...

workingctx: add a way for extensions to run code at status fixup time Some extensions like fsmonitor need to run code after dirstate.status is called, but while the wlock is held. The extensions could grab the wlock again, but that has its own peculiar race issues. For example, fsmonitor would not like its state to be written out if the dirstate has changed underneath (see issue5581 for what can go wrong in that sort of case). To protect against these sorts of issues, allow extensions to declare that they would like to run some code to run at fixup time. fsmonitor will switch to using this in the next patch in the series.

Augie Fackler - - Load All Authors

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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,

      )

      class dirstateguard(object):

          '''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._suffix = '.backup.%s.%d' % (name, id(self))

              repo.dirstate.savebackup(repo.currenttransaction(), self._suffix)

              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: dirstate%s")

                         % self._suffix)

                  raise error.Abort(msg)

              self._repo.dirstate.clearbackup(self._repo.currenttransaction(),

                                               self._suffix)

              self._active = False

              self._closed = True

          def _abort(self):

              self._repo.dirstate.restorebackup(self._repo.currenttransaction(),

                                                 self._suffix)

              self._active = False

          def release(self):

              if not self._closed:

                  if not self._active: # already inactivated

                      msg = (_("can't release already inactivated backup:"

                               " dirstate%s")

                             % self._suffix)

                      raise error.Abort(msg)

                  self._abort()

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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,
				)

				class dirstateguard(object):
				'''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._suffix = '.backup.%s.%d' % (name, id(self))
				repo.dirstate.savebackup(repo.currenttransaction(), self._suffix)
				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: dirstate%s")
				% self._suffix)
				raise error.Abort(msg)

				self._repo.dirstate.clearbackup(self._repo.currenttransaction(),
				self._suffix)
				self._active = False
				self._closed = True

				def _abort(self):
				self._repo.dirstate.restorebackup(self._repo.currenttransaction(),
				self._suffix)
				self._active = False

				def release(self):
				if not self._closed:
				if not self._active: # already inactivated
				msg = (_("can't release already inactivated backup:"
				" dirstate%s")
				% self._suffix)
				raise error.Abort(msg)
				self._abort()