comparison mercurial/changelog.py @ 47239:682f09857d69

revlogv2: delay the update of the changelog docket to transaction end

This prevent external reader to see the transaction content before it is
commited. However this also prevent the hooks to see the transaction content.
We will fix this in later changesets.

We have to temporarily suppress the error output of the command ran during the
transaction as they sometimes get confused about unknown working directory and
sometimes issue message on std-err in unspecified order.

Differential Revision: https://phab.mercurial-scm.org/D10629

47238:6597255a4f94

        # Ensure all updates go through this function
        assert isinstance(val, frozenset)
        self._filteredrevs = val
        self._filteredrevs_hashcache = {}

    def delayupdate(self, tr):
        """delay visibility of index updates to other readers"""
        if self._docket is not None:
            return

        if not self._delayed:
            if len(self) == 0:
                self._divert = True
                if self._realopener.exists(self._indexfile + b'.a'):
                    self._realopener.unlink(self._indexfile + b'.a')
                self.opener = _divertopener(self._realopener, self._indexfile)

    def _finalize(self, tr):
        """finalize index updates"""
        self._delayed = False
        self.opener = self._realopener
        # move redirected index data back into place
        if self._divert:
            assert not self._delaybuf
            tmpname = self._indexfile + b".a"
            nfile = self.opener.open(tmpname)
            nfile.close()
            self.opener.rename(tmpname, self._indexfile, checkambig=True)

47239:682f09857d69

        # Ensure all updates go through this function
        assert isinstance(val, frozenset)
        self._filteredrevs = val
        self._filteredrevs_hashcache = {}

    def _write_docket(self, tr):
        if not self._delayed:
            super(changelog, self)._write_docket(tr)

    def delayupdate(self, tr):
        """delay visibility of index updates to other readers"""
        if self._docket is None and not self._delayed:
            if len(self) == 0:
                self._divert = True
                if self._realopener.exists(self._indexfile + b'.a'):
                    self._realopener.unlink(self._indexfile + b'.a')
                self.opener = _divertopener(self._realopener, self._indexfile)

    def _finalize(self, tr):
        """finalize index updates"""
        self._delayed = False
        self.opener = self._realopener
        # move redirected index data back into place
        if self._docket is not None:
            self._write_docket(tr)
        elif self._divert:
            assert not self._delaybuf
            tmpname = self._indexfile + b".a"
            nfile = self.opener.open(tmpname)
            nfile.close()
            self.opener.rename(tmpname, self._indexfile, checkambig=True)