comparison mercurial/revlogutils/docket.py @ 47324:0a3fa41fa719

revlogv2: use a unique filename for data

Having a unique data will allow for ambiguity less rewriting of revlog content,
something useful to clarify handling of some operation like censoring or
stripping.

Differential Revision: https://phab.mercurial-scm.org/D10772

47323:f612db768c7a

#
# * 4 bytes: revlog version
#          |   This is mandatory as docket must be compatible with the previous
#          |   revlog index header.
# * 1 bytes: size of index uuid
# * 8 bytes: size of index-data
# * 8 bytes: pending size of index-data
# * 8 bytes: size of data
# * 8 bytes: pending size of data
# * 1 bytes: default compression header
S_HEADER = struct.Struct(constants.INDEX_HEADER.format + 'BLLLLc')


class RevlogDocket(object):
    """metadata associated with revlog"""

        self,
        revlog,
        use_pending=False,
        version_header=None,
        index_uuid=None,
        index_end=0,
        pending_index_end=0,
        data_end=0,
        pending_data_end=0,
        default_compression_header=None,

        self._dirty = False
        self._radix = revlog.radix
        self._path = revlog._docket_file
        self._opener = revlog.opener
        self._index_uuid = index_uuid
        # thes asserts should be True as long as we have a single index filename
        assert index_end <= pending_index_end
        assert data_end <= pending_data_end
        self._initial_index_end = index_end
        self._pending_index_end = pending_index_end

        """file path to the current index file associated to this docket"""
        # very simplistic version at first
        if self._index_uuid is None:
            self._index_uuid = make_uid()
        return b"%s-%s.idx" % (self._radix, self._index_uuid)

    @property
    def index_end(self):
        return self._index_end

        # this assert should be True as long as we have a single index filename
        assert official_data_end <= self._data_end
        data = (
            self._version_header,
            len(self._index_uuid),
            official_index_end,
            self._index_end,
            official_data_end,
            self._data_end,
            self.default_compression_header,
        )
        s = []
        s.append(S_HEADER.pack(*data))
        s.append(self._index_uuid)
        return b''.join(s)


def default_docket(revlog, version_header):
    """given a revlog version a new docket object for the given revlog"""

    offset = S_HEADER.size
    version_header = header[0]
    index_uuid_size = header[1]
    index_uuid = data[offset : offset + index_uuid_size]
    offset += index_uuid_size
    index_size = header[2]
    pending_index_size = header[3]
    data_size = header[4]
    pending_data_size = header[5]
    default_compression_header = header[6]
    docket = RevlogDocket(
        revlog,
        use_pending=use_pending,
        version_header=version_header,
        index_uuid=index_uuid,
        index_end=index_size,
        pending_index_end=pending_index_size,
        data_end=data_size,
        pending_data_end=pending_data_size,
        default_compression_header=default_compression_header,

47324:0a3fa41fa719

#
# * 4 bytes: revlog version
#          |   This is mandatory as docket must be compatible with the previous
#          |   revlog index header.
# * 1 bytes: size of index uuid
# * 1 bytes: size of data uuid
# * 8 bytes: size of index-data
# * 8 bytes: pending size of index-data
# * 8 bytes: size of data
# * 8 bytes: pending size of data
# * 1 bytes: default compression header
S_HEADER = struct.Struct(constants.INDEX_HEADER.format + 'BBLLLLc')


class RevlogDocket(object):
    """metadata associated with revlog"""

        self,
        revlog,
        use_pending=False,
        version_header=None,
        index_uuid=None,
        data_uuid=None,
        index_end=0,
        pending_index_end=0,
        data_end=0,
        pending_data_end=0,
        default_compression_header=None,

        self._dirty = False
        self._radix = revlog.radix
        self._path = revlog._docket_file
        self._opener = revlog.opener
        self._index_uuid = index_uuid
        self._data_uuid = data_uuid
        # thes asserts should be True as long as we have a single index filename
        assert index_end <= pending_index_end
        assert data_end <= pending_data_end
        self._initial_index_end = index_end
        self._pending_index_end = pending_index_end

        """file path to the current index file associated to this docket"""
        # very simplistic version at first
        if self._index_uuid is None:
            self._index_uuid = make_uid()
        return b"%s-%s.idx" % (self._radix, self._index_uuid)

    def data_filepath(self):
        """file path to the current index file associated to this docket"""
        # very simplistic version at first
        if self._data_uuid is None:
            self._data_uuid = make_uid()
        return b"%s-%s.dat" % (self._radix, self._data_uuid)

    @property
    def index_end(self):
        return self._index_end

        # this assert should be True as long as we have a single index filename
        assert official_data_end <= self._data_end
        data = (
            self._version_header,
            len(self._index_uuid),
            len(self._data_uuid),
            official_index_end,
            self._index_end,
            official_data_end,
            self._data_end,
            self.default_compression_header,
        )
        s = []
        s.append(S_HEADER.pack(*data))
        s.append(self._index_uuid)
        s.append(self._data_uuid)
        return b''.join(s)


def default_docket(revlog, version_header):
    """given a revlog version a new docket object for the given revlog"""

    offset = S_HEADER.size
    version_header = header[0]
    index_uuid_size = header[1]
    index_uuid = data[offset : offset + index_uuid_size]
    offset += index_uuid_size
    data_uuid_size = header[2]
    data_uuid = data[offset : offset + data_uuid_size]
    offset += data_uuid_size
    index_size = header[3]
    pending_index_size = header[4]
    data_size = header[5]
    pending_data_size = header[6]
    default_compression_header = header[7]
    docket = RevlogDocket(
        revlog,
        use_pending=use_pending,
        version_header=version_header,
        index_uuid=index_uuid,
        data_uuid=data_uuid,
        index_end=index_size,
        pending_index_end=pending_index_size,
        data_end=data_size,
        pending_data_end=pending_data_size,
        default_compression_header=default_compression_header,