[PATCH 2 of 8] discovery: move code for creating outgoing from heads and common (API)

[Gregory Szorc]

> On Aug 5, 2016, at 17:37, Pierre-Yves David <pierre-yves.david at ens-lyon.org> wrote:
> 
> 
> 
>> On 08/05/2016 05:16 AM, Gregory Szorc wrote:
>> # HG changeset patch
>> # User Gregory Szorc <gregory.szorc at gmail.com>
>> # Date 1470365488 25200
>> #      Thu Aug 04 19:51:28 2016 -0700
>> # Node ID 19d16c9bce2fdf86d8c84915a45815bb7d4fd932
>> # Parent  8a046444390debab5372de0b4f38863c57058f69
>> discovery: move code for creating outgoing from heads and common (API)
>> 
>> We recently moved similar code from changegroup.py to
>> discovery.outgoingbetween(). It makes sense for creation of outgoing
>> instances to all live together in discovery.py. So move
>> changegroup.computeoutgoing() to discovery.outgoingheadsandcommon() and
>> update consumers to use the new function.
> 
> I like the general idea of cleaning the changegroup API. but I think we can move toward something even saner:
> 
> With your series we end up with 3 way to obtains an outgoing object
> 
> - outgoingbetween(repo, roots, heads)
>  # root can be empty//False
> 
> - outgoingheadsandcommon(repo, heads, common)
>  # common will be filtered from locally missing
>  # heads can be empty (means all heads)
> 
> - outgoing(revlog, commonheads, missingheads):
> 
> That is probably 2 more function than we want.
> 
> First, even if the object will only bear a changelog object, all creators seems to have access to a repository anyway. So we can probably make the class internal and have all caller go through a builder function.
> 
> Second, we can probably have a single function handling all this with default value:
> 
> - outgoing(repo, roots=None, commonheads=None, heads=None)
>  # 'roots' and 'commonheads' cannot be both specified
>  # if neither 'roots' or 'commonheads' is set, 'commonheads' is nullid
>  # commonheads is filtered if specified
>  # heads=None mean 'all heads in the repo
> 
> In my opinion having a single high level API would make things much simpler.

I agree there is room to improve these APIs. However, that's work for a follow-up series. It's not something that interests me greatly. So if you want to write the patches, go for it.