Re: Merge policies

On Wed, May 2, 2012 at 12:47 PM, Philip Martin
<philip.martin_at_wandisco.com> wrote:
> Johan Corveleyn <jcorvel_at_gmail.com> writes:
>
>> On Fri, Apr 20, 2012 at 10:52 PM, Stefan Fuhrmann <eqfox_at_web.de> wrote:
>>> Am 19.04.2012 14:03, schrieb Johan Corveleyn:
>>>> - maybe propgetting through one of the bindings is much faster than
>>>> through svnlook, and you intend for admins to set this up with some
>>>> language bindings? In that case, keep in mind that bindings are not
>>>> always installed. Svnlook usually is always there.
>>>
>>>
>>> The problem is probably that svnlook is at a hefty
>>> disadvantage over e.g. the server because it has
>>> to open the FSFS repo anew for each access. Don't
>>> know really what to do about that.
>>
>> So the only way to get the "relevant property changes" really fast
>> with svnlook, would be with a command that gets everything with one
>> invocation, I guess.
>>
>> Actually, there is probably a way to get all those propchanges
>> quicker, by parsing the output of 'svnlook diff -t TXN'. But I've not
>> done the effort to do that.
>
> As suggested above, the bindings are fast:
>
> $ svnadmin create repo
> $ svn import -mm ../src file://`pwd`/repo/trunk   # import Subversion trunk
> $ svn co file://`pwd`/repo wc
> $ svn ps -R svn:mime-type foo/bar wc
> $ svn ci -mm wc
> $ ./x.py repo 2 | wc
>   2270    2270  141635
>
> Getting the mime-type for 2270 files takes less than 1 second.
>
>
> $ cat x.py
> #!/usr/bin/python
> import sys
> from svn import repos, fs
> r=repos.open(sys.argv[1])
> f=repos.fs(r)
> #t=fs.open_txn(f, sys.argv[2])
> t=fs.revision_root(f, int(sys.argv[2]))
> p=fs.paths_changed2(t)
> for key, val in p.iteritems():
>  print key + ":" + str(fs.node_prop(t, key, 'svn:mime-type'))

Nice. Thanks for testing. That's good to know.

That said, I think an improvement for svnlook is still sorely needed.
A lot of installations out there don't have bindings installed, plus a
lot of existing (sometimes publicly available) hooks are written for
svnlook (to be as generically useful as possible). Like this very nice
configurable pre-commit hook:

https://github.com/qazwart/SVN-Precommit-Kitchen-Sink-Hook

Anyway, I don't have the cycles to work on this myself, but I just
wanted to mention this as an important aspect if more and more tools
are going to validate properties in pre-commit hooks (like for
enforcing merge policies).

-- 
Johan