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Re: [PATCH 4/6] introduce a commit metapack

From
Jeff King <peff@peff.net>
Date
Feb 1, 2013, 09:21 UTC
Message-ID
<20130201092105.GD30644@sigill.intra.peff.net>
In-Reply-To
<7vk3qvm962.fsf@alter.siamese.dyndns.org>
On Tue, Jan 29, 2013 at 11:17:41PM -0800, Junio C Hamano wrote:
Show 5 quoted lines
> > True, but it is even less headache if the file is totally separate and
> > optional.
> 
> Once you start thinking about using an offset to some list of SHA-1,
> perhaps?  A section inside the same file can never go out of sync.

Yes, having a data dependency is important. It is unavoidable to have a dependency on the packfile, though (and that is why the index and the metapacks embed the sha1 of the packfile). If the offsets used are packfile offsets, then that is sufficient.

If the offsets are from the index, then yes, putting it in the same file is one way to keep them tied together. Another way is to do the same sha1 verification, except to embed the sha1 of the index in the metapack.

So I certainly consider putting the dependency-handling to be a point in favor of the same file, but I'd weight it against other points (headache of bumping index version, performance of both types, etc).

> Also a longer-term advantage is that you can teach index-pack to do
> this.

I think that is roughly the same amount of difficulty to do whether they are in the same file or not.

-Peff
Previous: Junio C HamanoNext: Junio C Hamano
Message 19 of 43 in “commit caching”
  1. 0/6 commit cachingJeff King, Jan 29, 2013
  2. 1/6 csum-file: make sha1write const-correctJeff King, Jan 29, 2013
  3. 2/6 strbuf: add string-chomping functionsJeff King, Jan 29, 2013
  4. Michael HaggertyJan 29, 2013
  5. Jeff KingJan 29, 2013
  6. Michael HaggertyJan 30, 2013
  7. 3/6 introduce pack metadata cache filesJeff King, Jan 29, 2013
  8. Junio C HamanoJan 29, 2013
  9. Jeff KingJan 30, 2013
  10. Duy NguyenJan 30, 2013
  11. Jeff KingJan 30, 2013
  12. 4/6 introduce a commit metapackJeff King, Jan 29, 2013
  13. Michael HaggertyJan 29, 2013
  14. Jeff KingJan 29, 2013
  15. Junio C HamanoJan 29, 2013
  16. Junio C HamanoJan 29, 2013
  17. Jeff KingJan 30, 2013
  18. Junio C HamanoJan 30, 2013
  19. Jeff KingFeb 1, 2013
  20. Junio C HamanoJan 30, 2013
  21. Shawn PearceJan 31, 2013
  22. Jeff KingFeb 1, 2013
  23. Junio C HamanoFeb 2, 2013
  24. Jeff KingJan 30, 2013
  25. Duy NguyenJan 30, 2013
  26. Jeff KingJan 30, 2013
  27. Duy NguyenJan 30, 2013
  28. Duy NguyenJan 30, 2013
  29. Duy NguyenJan 31, 2013
  30. Jeff KingFeb 1, 2013
  31. Duy NguyenFeb 2, 2013
  32. Jeff KingFeb 1, 2013
  33. Duy NguyenMar 17, 2013
  34. Jeff KingMar 18, 2013
  35. Jeff KingFeb 1, 2013
  36. 5/6 add git-metapack commandJeff King, Jan 29, 2013
  37. 6/6 commit: look up commit info in metapackJeff King, Jan 29, 2013
  38. Duy NguyenJan 30, 2013
  39. Jeff KingJan 30, 2013
  40. Duy NguyenJan 30, 2013
  41. Shawn PearceJan 31, 2013
  42. Jeff KingFeb 1, 2013
  43. Shawn PearceFeb 2, 2013

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