comparison mercurial/context.py @ 32814:2083d1643d69

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.

32813:6d73b7ff8f92

        return modified, deleted, fixup

    def _poststatusfixup(self, status, fixup):
        """update dirstate for files that are actually clean"""
        if fixup:
            try:
                oldid = self._repo.dirstate.identity()

                # updating the dirstate is optional
                # so we don't wait on the lock
                # wlock can invalidate the dirstate, so cache normal _after_
                # taking the lock
                with self._repo.wlock(False):
                    if self._repo.dirstate.identity() == oldid:
                        normal = self._repo.dirstate.normal
                        for f in fixup:
                            normal(f)
                        # write changes out explicitly, because nesting
                        # wlock at runtime may prevent 'wlock.release()'
                        # after this block from doing so for subsequent
                        # changing files
                        tr = self._repo.currenttransaction()
                        self._repo.dirstate.write(tr)
                    else:
                        # in this case, writing changes out breaks
                        # consistency, because .hg/dirstate was
                        # already changed simultaneously after last
                        # caching (see also issue5584 for detail)
                        self._repo.ui.debug('skip updating dirstate: '
                                            'identity mismatch\n')
            except error.LockError:
                pass

    def _dirstatestatus(self, match=None, ignored=False, clean=False,
                        unknown=False):
        '''Gets the status from the dirstate -- internal use only.'''
        listignored, listclean, listunknown = ignored, clean, unknown

32814:2083d1643d69

        return modified, deleted, fixup

    def _poststatusfixup(self, status, fixup):
        """update dirstate for files that are actually clean"""
        poststatus = self._repo.postdsstatus()
        if fixup or poststatus:
            try:
                oldid = self._repo.dirstate.identity()

                # updating the dirstate is optional
                # so we don't wait on the lock
                # wlock can invalidate the dirstate, so cache normal _after_
                # taking the lock
                with self._repo.wlock(False):
                    if self._repo.dirstate.identity() == oldid:
                        if fixup:
                            normal = self._repo.dirstate.normal
                            for f in fixup:
                                normal(f)
                            # write changes out explicitly, because nesting
                            # wlock at runtime may prevent 'wlock.release()'
                            # after this block from doing so for subsequent
                            # changing files
                            tr = self._repo.currenttransaction()
                            self._repo.dirstate.write(tr)

                        if poststatus:
                            for ps in poststatus:
                                ps(self, status)
                    else:
                        # in this case, writing changes out breaks
                        # consistency, because .hg/dirstate was
                        # already changed simultaneously after last
                        # caching (see also issue5584 for detail)
                        self._repo.ui.debug('skip updating dirstate: '
                                            'identity mismatch\n')
            except error.LockError:
                pass
            finally:
                # Even if the wlock couldn't be grabbed, clear out the list.
                self._repo.clearpostdsstatus()

    def _dirstatestatus(self, match=None, ignored=False, clean=False,
                        unknown=False):
        '''Gets the status from the dirstate -- internal use only.'''
        listignored, listclean, listunknown = ignored, clean, unknown