Re: [PATCH] raisin: Some git-checkout improvements

[George Dunlap <george.dunlap@eu.citrix.com>]

On 04/22/2015 03:11 PM, Stefano Stabellini wrote:
> On Tue, 21 Apr 2015, George Dunlap wrote:
>> 1. Switch local variables to lower-case and declare them local.
> 
> This is good.
> 
> 
>> 2. Cloning git trees from remote repos is often a very long operation.
>> Allow the user to specify a faster git cache as a prefix.
>>
>> 3. At the moment you can either check out a specific changeset or
>> "master", but you can't check out a different branch, because git
>> doesn't always look in origin/ for the branch.  If the initial git
>> checkout $tag fails, try checking out origin/$tag before giving up.
> 
> I am in two minds about this, because it is still possible for the user
> to simply:
> 
> LIBVIRT_REVISION="origin/blah"

Then we should have all the revisions point to "origin/master" for
consistency.

In any case, it requires the user to know the default remote repository
name.

>> Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
>> ---
>> CC: Stefano Stabellini <stefano.stabellini@citrix.com>
>> ---
>>  defconfig           |  3 +++
>>  lib/git-checkout.sh | 33 ++++++++++++++++++++-------------
>>  2 files changed, 23 insertions(+), 13 deletions(-)
>>
>> diff --git a/defconfig b/defconfig
>> index d3ef283..38c7455 100644
>> --- a/defconfig
>> +++ b/defconfig
>> @@ -35,3 +35,6 @@ QEMU_TRADITIONAL_REVISION="master"
>>  SEABIOS_REVISION="master"
>>  GRUB_REVISION="master"
>>  LIBVIRT_REVISION="master"
>> +
>> +# Git prefix.  Use this if you have a git caching proxy.
>> +#GIT_PREFIX=""
> 
> Are you aware that you can simply specify a directory in the URL
> variable?

I wasn't thinking of a local directory; I was thinking of the git proxy
running locally on drall; e.g.:

git://drall.uk.xensource.com:9419/git://xenbits.xen.org/xen.git

contacts a git proxy server running on drall, port 9419. If the proxy
server doesn't already have that repo, it will clone it; otherwise it
will just do a fetch.  Then it feeds you the info locally, which for a
clone is typically a *lot* faster than cloning remotely.  I think
Anthony has a git proxy running on his workstation too.

I was thinking of suggesting the name of a local caching proxy people
might wish to set up here; but ATM I'm just using the one that someone
else has already set up; I don't even know the name of either of the
ones I mentioned above. :-)

> Also wouldn't it be possible to achieve the same goal with the GIT
> environmental variable?

A brief scan of the git man page, combined with a brief survey of
Google, didn't turn up anything...

>> -	    cd $DIR-remote.tmp
>> +	    cd $dir-remote.tmp
>>  	    $GIT branch -D dummy >/dev/null 2>&1 ||:
>> -	    $GIT checkout -b dummy $TAG
>> +	    $GIT checkout -b dummy $tag \
>> +		|| $GIT checkout -b dummy origin/$tag
> 
> XXX

Is this actually a comment, or just a placeholder of some sort? :-)

 -George