Re: [Gnu-arch-users] [PATCH] arch speedups on big trees

[Tom Lord]

    > From: Andrew Suffield <address@hidden>

    > Actually, that suggests a variation that makes more sense:

    > When we're trying to modify or delete the file with id X, we don't
    > really want to know the path of every file in the tree - just the one
    > with id X. So, start by asking "Does the file at path foo have id X?",
    > and if it does, stop. If it doesn't, scan outwards until we find it
    > (simplified form: scan the whole tree).

    > That'll require a bit of refactoring of the inventory interface, I
    > think, but shouldn't be too hard. It should work for any changeset
    > application.

    > Adding a file is the exceptional case - we have to scan the whole tree
    > for that. But it doesn't happen very often in general, so that's
    > probably a reasonable cutoff point for the optimisation.

My hunch is that you're proposing a fairly large amount of code work
and resulting complexity for, after the inode-sig-implies-id hack
being extended to handle explicit tags, a relatively small return.

I'd be much happier just to see a first cut at mason's optimization
that only tries to handle the exact-patching case.

-t