comparison mercurial/revlog.py @ 40325:b0fbd1792e2d

storageutil: extract most of peek_censored from revlog

This function is super hacky and isn't correct 100% of the time. I'm going
to need this functionality on a future non-revlog store.

Let's copy things to storageutil so this code only exists once.

Differential Revision: https://phab.mercurial-scm.org/D5118

40324:6637b079ae45

    def _peek_iscensored(self, baserev, delta, flush):
        """Quickly check if a delta produces a censored revision."""
        if not self._censorable:
            return False

        # Fragile heuristic: unless new file meta keys are added alphabetically
        # preceding "censored", all censored revisions are prefixed by
        # "\1\ncensored:". A delta producing such a censored revision must be a
        # full-replacement delta, so we inspect the first and only patch in the
        # delta for this prefix.
        hlen = struct.calcsize(">lll")
        if len(delta) <= hlen:
            return False

        oldlen = self.rawsize(baserev)
        newlen = len(delta) - hlen
        if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen):
            return False

        add = "\1\ncensored:"
        addlen = len(add)
        return newlen >= addlen and delta[hlen:hlen + addlen] == add

    def getstrippoint(self, minlink):
        """find the minimum rev that must be stripped to strip the linkrev

        Returns a tuple containing the minimum rev and a set of all revs that

40325:b0fbd1792e2d

    def _peek_iscensored(self, baserev, delta, flush):
        """Quickly check if a delta produces a censored revision."""
        if not self._censorable:
            return False

        return storageutil.deltaiscensored(delta, baserev, self.rawsize)

    def getstrippoint(self, minlink):
        """find the minimum rev that must be stripped to strip the linkrev

        Returns a tuple containing the minimum rev and a set of all revs that