[Buildbot-devel] Status of hg polling

[Georges Racinet]

Le 30/05/2012 21:21, Tom Prince a écrit :
> Georges Racinet<gracinet at anybox.fr>  writes:
>> After a quick read of GitPoller and its tests, that doesn't seem very
>> hard to adapt to Mercurial. What it relies on is fetching the changes by
>> calling the git executable in a subprocess.
> One thing that the current git poller doesn't do well, is handle changed
> settings or messed up poller directory. If you are writting an hg
> poller, it would be good to make it reslient, i.e. check the state of
> the repository, rather than making assumptions about the state, like the
> git poller does.
Ok. The worse experience I have in this department is the bzr 
executable, though : it leaves hard to break locks behind in case of 
interruption, is frail wrt to dirty upstream practices, and extreme 
measures such as wipe and branch again have a big performance impact.

>
>> I don't know if importing mercurial from python could further allow to
>> avoid actually transmitting the changesets, but that would be much
>> harder to maintain anyway, as it's officially not stable (some
>> experience with Mercurial internals, here)
> On thing to be carefulof, if you do this, is that any blocking code
> needs to be in a thread (using deferToThread).
Due noted, and I think there's an example of that in BzrPoller. In a 
first run, I'd go the easier subprocess way, though.
>> A question though : I see that BzrPoller is in contrib while GitPoller
>> is in the main package. What's the reason ? If I were to try and
>> contribute some generic HgPoller (with tests), where should I put it, then ?
> I'm not sure if there is any big reason. Perhaps partly because
> bzr_buildbot mixes polling code, with commit hook code (the latter
> typically lives inside contrib). If you are submitting a new change
> source, it probably belongs in the main pacakge.
Thanks, I'll try to sneak a few hours to begin experiments this 
week-end, in a branch taken from current master. I'll open a ticket on 
the trac to keep the community posted (I guess a serious staging on our 
buildbots is necessary before any merge)

Best,