Plumbing version of 'git branch --contains' ?

[Crabtree, Andrew]

I need to get a list of refs that can reach a certain SHA in in a script.

git branch --contains SHA

would be great (runs in ~2 seconds), but not my preferred option for scripting.

I tried

for br in $(git for-each-ref --format='%(refname:short)' refs/heads/)
do
git merge-base --is-ancestor $1 ${br}
if [ $? -eq 0 ]
then
echo "${br}"
fi
done

Which gives me perfect output, but takes 82 seconds to run in my environment.

Is there an alternative I'm missing to give me the run time performance of 'git branch --contains' but with stable output suitable for parsing?

Thanks in advance,
-Andrew

[Jeff King]

Post by Crabtree, Andrew
I need to get a list of refs that can reach a certain SHA in in a script.
git branch --contains SHA
would be great (runs in ~2 seconds), but not my preferred option for scripting.
I tried
for br in $(git for-each-ref --format='%(refname:short)' refs/heads/)
do
git merge-base --is-ancestor $1 ${br}
if [ $? -eq 0 ]
then
echo "${br}"
fi
done
Which gives me perfect output, but takes 82 seconds to run in my environment.

Right. There's some setup work that happens in `git branch --contains`
that we end up repeating.

Post by Crabtree, Andrew
Is there an alternative I'm missing to give me the run time
performance of 'git branch --contains' but with stable output suitable
for parsing?

Sadly, no, there isn't currently. The right tool would be `git
for-each-ref --contains`, but it doesn't exist yet. I was working
towards it, but got stopped on factoring out a `--contains` traversal
suitable for both `git tag` and `git branch` (they currently are
different and make performance tradeoffs based on the expected depth of
the merge bases, which is usually different between tags and
branches)[1]. That's work I'd love to resume, but I haven't gotten
around to it yet.

-Peff

[1] http://thread.gmane.org/gmane.comp.version-control.git/252472

[Junio C Hamano]

Post by Jeff King

Post by Crabtree, Andrew
I need to get a list of refs that can reach a certain SHA in in a script.
git branch --contains SHA
would be great (runs in ~2 seconds), but not my preferred option for scripting.
I tried
for br in $(git for-each-ref --format='%(refname:short)' refs/heads/)
do
git merge-base --is-ancestor $1 ${br}
if [ $? -eq 0 ]
then
echo "${br}"
fi
done
Which gives me perfect output, but takes 82 seconds to run in my environment.

Right. There's some setup work that happens in `git branch --contains`
that we end up repeating.

Post by Crabtree, Andrew
Is there an alternative I'm missing to give me the run time
performance of 'git branch --contains' but with stable output suitable
for parsing?

Sadly, no, there isn't currently. The right tool would be `git
for-each-ref --contains`, but it doesn't exist yet. I was working
towards it, but got stopped on factoring out a `--contains` traversal
suitable for both `git tag` and `git branch` (they currently are
different and make performance tradeoffs based on the expected depth of
the merge bases, which is usually different between tags and
branches)[1]. That's work I'd love to resume, but I haven't gotten
around to it yet.
-Peff
[1] http://thread.gmane.org/gmane.comp.version-control.git/252472

Thanks for status update. I was wondering if I should start looking
into it myself.