mercurial/revlog.py

40669:39369475445c

        If an existing file handle is passed, it will be seeked and the
        original seek position will NOT be restored.

        Returns a str or buffer of raw byte data.
        """
        # Cache data both forward and backward around the requested
        # data, in a fixed size window. This helps speed up operations
        # involving reading the revlog backwards.
        cachesize = self._chunkcachesize

        reallength = (((offset + length + cachesize) & ~(cachesize - 1))
                      - realoffset)
        with self._datareadfp(df) as df:
            df.seek(realoffset)
            d = df.read(reallength)
        self._cachesegment(realoffset, d)
        if offset != realoffset or reallength != length:
            return util.buffer(d, offset - realoffset, length)
        return d

    def _getsegment(self, offset, length, df=None):
        """Obtain a segment of raw data from the revlog.

40670:87a872555e90

        If an existing file handle is passed, it will be seeked and the
        original seek position will NOT be restored.

        Returns a str or buffer of raw byte data.

        Raises if the requested number of bytes could not be read.
        """
        # Cache data both forward and backward around the requested
        # data, in a fixed size window. This helps speed up operations
        # involving reading the revlog backwards.
        cachesize = self._chunkcachesize

        reallength = (((offset + length + cachesize) & ~(cachesize - 1))
                      - realoffset)
        with self._datareadfp(df) as df:
            df.seek(realoffset)
            d = df.read(reallength)

        self._cachesegment(realoffset, d)
        if offset != realoffset or reallength != length:
            startoffset = offset - realoffset
            if len(d) - startoffset < length:
                raise error.RevlogError(
                    _('partial read of revlog %s; expected %d bytes from '
                      'offset %d, got %d') %
                    (self.indexfile if self._inline else self.datafile,
                     length, realoffset, len(d) - startoffset))

            return util.buffer(d, startoffset, length)

        if len(d) < length:
            raise error.RevlogError(
                _('partial read of revlog %s; expected %d bytes from offset '
                  '%d, got %d') %
                (self.indexfile if self._inline else self.datafile,
                 length, offset, len(d)))

        return d

    def _getsegment(self, offset, length, df=None):
        """Obtain a segment of raw data from the revlog.