comparison mercurial/revlog.py @ 47387:75e1104f23a2

revlog: use dedicated code for reading sidedata

We are about to introduce a new, dedicated, file to store sidedata. Before doing so, we make sidedata reading go through different code as reading data chunk. This will simplify some of the complexity of the next changesets.

The reading is very simple right now and will need some improvement later to
reuse some of the caching strategy we use for the data file.

Differential Revision: https://phab.mercurial-scm.org/D10785

47386:0d0fb091c49f

                func = self._indexfp
            else:
                func = self._datafp
            with func() as fp:
                yield fp

    def tiprev(self):
        return len(self.index) - 1

    def tip(self):

        if self._inline:
            sidedata_offset += self.index.entry_size * (1 + rev)
        if sidedata_size == 0:
            return {}

        comp_segment = self._getsegment(sidedata_offset, sidedata_size)
        comp = self.index[rev][11]
        if comp == COMP_MODE_PLAIN:
            segment = comp_segment
        elif comp == COMP_MODE_DEFAULT:
            segment = self._decompressor(comp_segment)

47387:75e1104f23a2

                func = self._indexfp
            else:
                func = self._datafp
            with func() as fp:
                yield fp

    def _sidedatareadfp(self):
        """file object suitable to read sidedata"""
        return self._datareadfp()

    def tiprev(self):
        return len(self.index) - 1

    def tip(self):

        if self._inline:
            sidedata_offset += self.index.entry_size * (1 + rev)
        if sidedata_size == 0:
            return {}

        # XXX this need caching, as we do for data
        with self._sidedatareadfp() as sdf:
            sdf.seek(sidedata_offset)
            comp_segment = sdf.read(sidedata_size)

            if len(comp_segment) < sidedata_size:
                filename = self._datafile
                length = sidedata_size
                offset = sidedata_offset
                got = len(comp_segment)
                m = PARTIAL_READ_MSG % (filename, length, offset, got)
                raise error.RevlogError(m)

        comp = self.index[rev][11]
        if comp == COMP_MODE_PLAIN:
            segment = comp_segment
        elif comp == COMP_MODE_DEFAULT:
            segment = self._decompressor(comp_segment)