Re: heads-up: git-index-pack in "next" is broken
- From
Linus Torvalds <torvalds@osdl.org>
- Date
- Oct 18, 2006, 21:48 UTC
- Message-ID
- <Pine.LNX.4.64.0610181434510.3962@g5.osdl.org>
- In-Reply-To
- <Pine.LNX.4.64.0610181407040.18885@alien.or.mcafeemobile.com>
On Wed, 18 Oct 2006, Davide Libenzi wrote:
> > The hash value (hence the hash bucket index) simply directs you to the > bucket where a real record-compare loop is performed.
As far as I can tell not all loops do a real "record-compare" thing.
Some of the hash loops _only_ look at the hash, and as such a bad hash will do more than just cause bad performance, it will actually degrade the diff itself. Isn't that what XDL_MAX_EQLIMIT effectively does?
Btw, the binary delta generator doesn't seem to have this issue at all: it uses "unsigned int" for the hash values, so the xdiff delta generation will give the same exact results on 32-bit and 64-bit architectures.
Or was that one of the changes by Nico? (I only looked at the git version of that code)
Linus