threads / discuss / 28839

Find the size of git push in pre-receive hook

Subject: Find the size of git push in pre-receive hook

## tl;dr

5 messages between Nov 4, 2011 and Nov 8, 2011.

replies: 4people: 4as markdown or json

manigandans· Nov 4, 2011, 09:20 UTC · lore

Hi,

I want to restrict the size of the push on the git remote repository. How can I find the size of the push in pre-receive hook?

Thanks a lot in advance.

Best regards, Manigandan S.

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Magnus Bäck· Nov 4, 2011, 09:46 UTC · re: manigandans · lore

Re: Find the size of git push in pre-receive hook

On Friday, November 04, 2011 at 10:20 CET,
     manigandans <etc.mani@gmail.com> wrote:

> I want to restrict the size of the push on the git remote repository.
> How can I find the size of the push in pre-receive hook?

What does "size of the push" mean to you? Number of bytes transmitted over the wire? Number of commits pushed? Number of refs updated? Number of files modified? Number of lines modified? Something else?

-- 
Magnus Bäck                   Opinions are my own and do not necessarily
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Junio C Hamano· Nov 4, 2011, 18:01 UTC · re: manigandans · lore

Re: Find the size of git push in pre-receive hook

manigandans <etc.mani@gmail.com> writes:

> I want to restrict the size of the push on the git remote repository. How
> can I find the size of the push in pre-receive hook?

You don't.

What are you trying to solve?

The thing is, by the time pre-receive-hook is run, the packs have already been transferred to the destination. Otherwise pre-receive-hook cannot do its primary task of inspecting the history the push is trying to update the refs with and allow or deny the ref updates.

Presumably you could run "git rev-list --objects" between the values of refs before and after the proposed updates, sum up their sizes and reject the push when the push adds too much data for your liking, and the next gc will clean things up, but if your goal is to cap the maximum disk quota including the transient use during the time pre-receive-hook is run, it would not help.

Junio C Hamano· Nov 7, 2011, 05:42 UTC · lore

Re: Find the size of git push in pre-receive hook

Manigandan S <etc.mani@gmail.com> writes:

> Let me explain it in detail, if I was not clear.

Do not top-post on this list.

You said you wanted to restrict the size of a push, but what you are trying is to restrict the size of a repository after a push. If accepting this push will result in your repository go over the quota, the push will be denied. Otherwise the push will be accepted.

If that is the case, how much the resulting repository weighs is what you are trying to measure, not the size of _this_ push, i.e. the amount of additional data this push will introduce, and "du -s" for the repository inside pre-receive-hook is the way to do so.

Jeff King· Nov 8, 2011, 05:41 UTC · re: Junio C Hamano · lore

Re: Find the size of git push in pre-receive hook

On Sun, Nov 06, 2011 at 09:42:37PM -0800, Junio C Hamano wrote:

Show 15 quoted lines

> Manigandan S <etc.mani@gmail.com> writes:
> 
> > Let me explain it in detail, if I was not clear.
> 
> Do not top-post on this list.
> 
> You said you wanted to restrict the size of a push, but what you are
> trying is to restrict the size of a repository after a push. If accepting
> this push will result in your repository go over the quota, the push will
> be denied. Otherwise the push will be accepted.
> 
> If that is the case, how much the resulting repository weighs is what you
> are trying to measure, not the size of _this_ push, i.e. the amount of
> additional data this push will introduce, and "du -s" for the repository
> inside pre-receive-hook is the way to do so.

I'm not sure even "du -s" is a good method. That will tell you how big this push is right _now_, which is at least a maximum. But most commits, when packed with other commits, will take up a fraction of that space due to deltas.

So you might receive a 100K thin pack on the network that git will explode to a 5 megabyte full pack on disk. Next time you repack, it will only increase the size of your existing packed data by 100K or so.

If receive-pack actually measured the incoming pack bytes in the thin pack, that would probably be a more accurate guess (but again, it's still just a guess).

-Peff