Re: [PATCH] Add contrib/rerere-train script

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Sep 29, 2008, 12:39 UTC
Message-ID: <alpine.DEB.1.00.0809291430050.16478@pacific.mpi-cbg.de.mpi-cbg.de>
In-Reply-To: <20080927204415.6117@nanako3.lavabit.com>

Hi,

On Sat, 27 Sep 2008, Nanako Shiraishi wrote:

> This script takes a range of commits (e.g. maint..next) as its 
> arguments, recreates merge commits in the range to prime rr-cache 
> database.

Cute idea. However, I would _love_ to have this as an option to git-rerere, which would work in memory only.

This is how I would do it (if I had enough time to play with Git):

- teach merge_recursive_options not to write anything to the working 
  directory (should be relatively easy, as many parts of merge-recursive.c 
  already have no_wd/update_wd/!o->call_depth checks for that),

- refactor handle_file() in rerere.c to provide an in-memory-only version,

- teach rerere to call merge_recursive() with the in-memory-only option, 
  and then call the in-memory version of the handle_file() function for 
  all unmerged paths, using the resolutions from the given merge commit.

- then teach this new function to take an arbitrary commit range (but only 
  handling the two-parent merges within it).

Ciao, Dscho