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From: Jonathan Nieder <jrnieder@gmail.com>
To: Jakub Narebski <jnareb@gmail.com>
Cc: Jeff King <peff@peff.net>, Shawn Pearce <spearce@spearce.org>,
	Ramkumar Ramachandra <artagnon@gmail.com>,
	Jens Lehmann <Jens.Lehmann@web.de>,
	Christian Couder <chriscool@tuxfamily.org>,
	Thomas Rast <trast@student.ethz.ch>, git <git@vger.kernel.org>,
	David Barr <david.barr@cordelta.com>,
	Elijah Newren <newren@gmail.com>
Subject: History surgery with fast-import (Re: Summer of Code project ideas due this Friday)
Date: Fri, 11 Mar 2011 18:20:17 -0600	[thread overview]
Message-ID: <20110312002017.GA16081@elie> (raw)
In-Reply-To: <m339mu7u6n.fsf@localhost.localdomain>

Jakub Narebski wrote:
> Jonathan Nieder <jrnieder@gmail.com> writes:

>> 4. filter-branch killer: using fast-import's new features to implement
>>    common filter-branch operations (--subdirectory-filter,
>>    --prune-empty, obliterating certain files) faster.
>
> How it would be different from existing reposurgeon tool by ESR
> (cross-VC thanks to using fast-import format), or git_fast_filter by
> Elijah Newren (more of a library than a ready tool)?

Good question.

. reposurgeon loads the whole history into a convenient format,
  manipulates it, then dumps it as a separate step.  So it is even more
  flexible than filter-branch, but with a large history and especially
  on a small machine it can be slower.

. git_fast_filter is what Thomas mentioned --- a filter to go between
  fast-export and fast-import.

Both involve unpacking all trees.  Which is not a huge expense, mind
you, but there is room to go faster.

What I was suggesting is instead a tool that relies on fast-import to
do the heavy lifting.  So, for example, when you ask to delete
path/to/remove.txt from all commits, it would write:

 commit refs/heads/master
 mark :172
 author A U Thor <author@example.com> ...
 committer ...
 data ...
 from ...
 merge ...
 M 040000 [old tree name for that commit] ""
 D path/to/remove.txt

 commit refs/heads/mater
 mark :173
 ...

The idea is inspired by
http://thread.gmane.org/gmane.comp.version-control.git/158375
I am interested in it because I imagine something like this could be
useful for splitting out branches from a naive import of an svn repo
(and similar surgeries).

  parent reply	other threads:[~2011-03-12  0:20 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-03 18:08 Google Summer of Code 2011 Shawn Pearce
2011-03-03 18:59 ` Jeff King
2011-03-03 19:04   ` Shawn Pearce
2011-03-03 20:33     ` Jeff King
2011-03-03 21:25       ` Jakub Narebski
2011-03-09 16:38         ` Jeff King
2011-03-09 16:39       ` Jeff King
2011-03-09 16:47         ` Shawn Pearce
2011-03-09 17:49       ` Jeff King
2011-03-09 17:52         ` Shawn Pearce
2011-03-09 21:58           ` Summer of Code project ideas due this Friday Jeff King
2011-03-10  0:10             ` Jonathan Nieder
2011-03-10 16:30               ` Jeff King
2011-03-10 17:31                 ` Shawn Pearce
2011-03-10 21:43                   ` Alexander Miseler
2011-03-10 17:15               ` Thomas Rast
2011-03-10 18:17                 ` Santi Béjar
2011-03-10 18:46                 ` Jeff King
2011-03-10 19:21                   ` Junio C Hamano
2011-03-10 19:28                     ` Jeff King
2011-03-10 20:54                       ` Junio C Hamano
2011-03-10 21:42                         ` Jeff King
2011-03-10 22:58                           ` Junio C Hamano
2011-03-10 23:09                             ` Jeff King
2011-03-11 13:31                   ` Thomas Rast
2011-03-10 17:39               ` Jakub Narebski
2011-03-11 13:28                 ` Thomas Rast
2011-03-12  0:20                 ` Jonathan Nieder [this message]
2011-03-13 17:08               ` Ramkumar Ramachandra
2011-03-10  0:19             ` Nguyen Thai Ngoc Duy
2011-03-10 16:31               ` Jeff King
2011-03-10 21:40             ` Alexander Miseler
2011-03-10 22:18               ` Jeff King
2011-03-11 14:17                 ` Alexander Miseler
2011-03-12 19:47                   ` Alexander Miseler
2011-03-11 12:18             ` Alexander Miseler
2011-03-11 12:52               ` Ilari Liusvaara
2011-03-11 13:48                 ` Nguyen Thai Ngoc Duy
2011-03-11 14:10                   ` Alexander Miseler
2011-03-11 14:27                     ` Nguyen Thai Ngoc Duy
2011-03-11 22:42                       ` Sam Vilain
2011-03-12 21:41                       ` Alexander Miseler
2011-03-11 12:43             ` Ævar Arnfjörð Bjarmason
2011-03-11 14:24               ` code.sculptor
2011-03-17 23:40             ` Summer of Code project ideas Jakub Narebski
2011-03-22 20:31               ` Heiko Voigt
2011-03-22 22:55               ` J.H.
2011-03-25  1:11               ` Pat Thoyts
2011-03-25 13:02                 ` Jakub Narebski
2011-03-03 21:04 ` Google Summer of Code 2011 Ramkumar Ramachandra
2011-03-03 22:08   ` Jonathan Nieder
2011-03-07 12:15   ` Sverre Rabbelier
2011-03-08 12:33     ` Ramkumar Ramachandra
2011-03-08 12:49       ` Sverre Rabbelier
2011-03-03 22:38 ` Jens Lehmann
2011-03-05  4:05 ` Christian Couder
2011-03-06 19:24 ` Sam Vilain
2011-03-07 19:40 ` Heiko Voigt
2011-03-07 20:50   ` Fredrik Gustafsson
2011-03-09 21:52     ` Heiko Voigt
2011-03-09 23:16       ` Fredrik Gustafsson
2011-03-10 22:46         ` Heiko Voigt
2011-03-09 15:18 ` Thomas Rast

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