comparison mercurial/revlog.py @ 47294:93a0abe098e7

revlog: avoid raising no-arg RevlogError for internal flow control

I'm about to make RevlogError require a `message` argument and this
code was failing. This patch refactors it to not raise an exception
for intra-function flow control.

Differential Revision: https://phab.mercurial-scm.org/D10740

47293:7a769ac49637

                pass

    def _partialmatch(self, id):
        # we don't care wdirfilenodeids as they should be always full hash
        maybewdir = self.nodeconstants.wdirhex.startswith(id)
        try:
            partial = self.index.partialmatch(id)
            if partial and self.hasnode(partial):
                if maybewdir:
                    # single 'ff...' match in radix tree, ambiguous with wdir
                    raise error.RevlogError
                return partial
            if maybewdir:
                # no 'ff...' match in radix tree, wdir identified
                raise error.WdirUnsupported
            return None
        except error.RevlogError:
            # parsers.c radix tree lookup gave multiple matches
            # fast path: for unfiltered changelog, radix tree is accurate
            if not getattr(self, 'filteredrevs', None):
                raise error.AmbiguousPrefixLookupError(
                    id, self.display_id, _(b'ambiguous identifier')
                )
            # fall through to slow path that filters hidden revisions
        except (AttributeError, ValueError):
            # we are pure python, or key was too short to search radix tree
            pass

        if id in self._pcache:
            return self._pcache[id]

        if len(id) <= 40:

47294:93a0abe098e7

                pass

    def _partialmatch(self, id):
        # we don't care wdirfilenodeids as they should be always full hash
        maybewdir = self.nodeconstants.wdirhex.startswith(id)
        ambiguous = False
        try:
            partial = self.index.partialmatch(id)
            if partial and self.hasnode(partial):
                if maybewdir:
                    # single 'ff...' match in radix tree, ambiguous with wdir
                    ambiguous = True
                else:
                    return partial
            elif maybewdir:
                # no 'ff...' match in radix tree, wdir identified
                raise error.WdirUnsupported
            else:
                return None
        except error.RevlogError:
            # parsers.c radix tree lookup gave multiple matches
            # fast path: for unfiltered changelog, radix tree is accurate
            if not getattr(self, 'filteredrevs', None):
                ambiguous = True
            # fall through to slow path that filters hidden revisions
        except (AttributeError, ValueError):
            # we are pure python, or key was too short to search radix tree
            pass
        if ambiguous:
            raise error.AmbiguousPrefixLookupError(
                id, self.display_id, _(b'ambiguous identifier')
            )

        if id in self._pcache:
            return self._pcache[id]

        if len(id) <= 40: