efficient way to filter several branches with common history?

Is there an efficient way to filter several branches at once through git-filter-branch? Often several branches have a lot of common history. Therefore, I suspect it would be much more efficient to filter them with one call to git-filter-branch. For example how can I efficiently filter all origin/* branches to filtered/* branches?

	Steffen

Steffen Prohaska wrote:

That feature is not yet implemented.

In the meantime do it this way:

Make an octopus merge of the branches onto a new branch. (If you have more than a dozen or so, you better make a hierarchy of octopusses.) You don't need to resolve conflicts (you are not interested in the merge result), or use -s ours to avoid them in the first place. Then filter that new branch. Then create new refs at the rewritten commits:

   $ git update-ref refs/filtered/b1 $id-of-rewritten-origin/b1
   $ ...

Use gitk to find the $ids-of-rewritten-origin/*

-- Hannes

On Jul 4, 2007, at 10:37 AM, Johannes Sixt wrote:

Thanks for your explanation. The following is the template I used to build my fully automated version of what you proposed:

--- SNIP --- echo "merging branches to be filtered ..." git-checkout -b tmp/all origin/master

for b in origin/branchX origin/branchY [ ... more branches here ...]
do
     git merge -s ours -m "merge-for-preparing-filter-branch $b" $b
done

echo "... filtering ..."
git-filter-branch \
[... your git-filter-branch filters here ...] \
   filtered/all >filter-branch.log

echo "... setting heads of filtered branches."
lastp1=
git-log --pretty="format:%s %P" filtered/all |
while read t b p1 p2
do
     [[ "$t" == "merge-for-preparing-filter-branch" ]] || { git  
update-ref refs/heads/filtered/master $lastp1 ; break ; }
     b=filtered/$(basename $b)
     git update-ref refs/heads/$b $p2
     lastp1=$p1
done

echo "delete tmp/all and filtered/all after checking the result" --- SNIP ---

	Steffen

Hi,

On Wed, 4 Jul 2007, Steffen Prohaska wrote:

Since you seem quite proficient in shell, why not implement this feature in filter-branch (which is a shell script) to begin with?

Ciao, Dscho