Re: [RFC PATCH 1/4] Document the HTTP transport protocol

From: Shawn O. Pearce <spearce@spearce.org>
Date: Oct 15, 2009, 16:39 UTC
Message-ID: <20091015163904.GN10505@spearce.org>
In-Reply-To: <loom.20091009T104530-586@post.gmane.org>

Alex Blewitt <Alex.Blewitt@gmail.com> wrote:

Show 6 quoted lines

> Shawn O. Pearce <spearce <at> spearce.org> writes:
> 
> > +URL Format
> > +----------
> 
> It's worth making clear here that $GIT_URL will be the path to the repository,

...

Thanks, noted.

> > HEX = [0-9a-f]
> 
> Is there any reason not to support A-F as well in the hex spec, even if they
> SHOULD use a-f?

Consistency. I'd rather be strict and say HEX is [0-9a-f] and demand that everyone try to standardize on the lower case form.

> This may limit the appeal for some case-insensitive systems.

Given that this particular notation of HEX is *only* used within the protocol body to describe SHA-1 IDs, it won't make it to the file system as-is.

A conforming Git implementation would first validate that this is in
fact a SHA-1 ID, likely translate it into a binary representation
(that is collapse the 40 byte hex to a 20 byte binary), and then
reformat it as a file system path if its looking for a loose object.

> It would also be good to document, like with the git daemon, whether all
> repositories under a path are exported or only those that have the magic
> setting in the config like git-daemon-export-ok.

This isn't something that matters to the protocol specification. Its a server access control, not protocol detail.

Really, its an implementation detail of git-http-backend in git.git, or of the RepositoryResolver and UploadPackFactory in JGit.

Therefore, its not going to be documented in this document.

> Lastly, it would be good to clarify when the result of this GET/POST exchange
> is a text-based (and encoded in UTF-8) vs when binary data is returned; we 
> don't want to get into the state where we're returning binary data and 
> pretending that it's UTF-8.

Oh, right.

-- 
Shawn.