comparison mercurial/pure/parsers.py @ 47078:223b47235d1c

sidedata: enable sidedata computers to optionally rewrite flags

Sidedata computers may want to influence the flags of the revision they touch.
For example, the computer for changelog-based copytracing can add a flag to
signify that this revision might affect copytracing, inversely removing said
flag if the information is no longer applicable.

See inline documentation in `storageutil` for more details.

Differential Revision: https://phab.mercurial-scm.org/D10344

47077:119790e1c67c

class Index2Mixin(object):
    index_format = revlog_constants.INDEX_ENTRY_V2
    null_item = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid, 0, 0)

    def replace_sidedata_info(self, i, sidedata_offset, sidedata_length):
        """
        Replace an existing index entry's sidedata offset and length with new
        ones.
        This cannot be used outside of the context of sidedata rewriting,
        inside the transaction that creates the revision `i`.

        sidedata_format = b">Qi"
        packed_size = struct.calcsize(sidedata_format)
        if i >= self._lgt:
            packed = _pack(sidedata_format, sidedata_offset, sidedata_length)
            old = self._extra[i - self._lgt]
            new = old[:64] + packed + old[64 + packed_size :]
            self._extra[i - self._lgt] = new
        else:
            msg = b"cannot rewrite entries outside of this transaction"
            raise KeyError(msg)

47078:223b47235d1c

class Index2Mixin(object):
    index_format = revlog_constants.INDEX_ENTRY_V2
    null_item = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid, 0, 0)

    def replace_sidedata_info(
        self, i, sidedata_offset, sidedata_length, offset_flags
    ):
        """
        Replace an existing index entry's sidedata offset and length with new
        ones.
        This cannot be used outside of the context of sidedata rewriting,
        inside the transaction that creates the revision `i`.

        sidedata_format = b">Qi"
        packed_size = struct.calcsize(sidedata_format)
        if i >= self._lgt:
            packed = _pack(sidedata_format, sidedata_offset, sidedata_length)
            old = self._extra[i - self._lgt]
            offset_flags = struct.pack(b">Q", offset_flags)
            new = offset_flags + old[8:64] + packed + old[64 + packed_size :]
            self._extra[i - self._lgt] = new
        else:
            msg = b"cannot rewrite entries outside of this transaction"
            raise KeyError(msg)