[PATCH 1 of 4 V2] flagutil: introduce a flagprocessorsmixin class

[Pierre-Yves David]

On 8/31/19 5:02 AM, Yuya Nishihara wrote:
> On Sun, 11 Aug 2019 13:10:47 +0200, Pierre-Yves David wrote:
>> # HG changeset patch
>> # User Pierre-Yves David <pierre-yves.david at octobus.net>
>> # Date 1565219568 -7200
>> #      Thu Aug 08 01:12:48 2019 +0200
>> # Node ID e6d22ec889461dbe819e0dbf4d2f0167736b2416
>> # Parent  6d61be152c5515fed315885f6c9cf9defe73de71
>> # EXP-Topic flag-processors
>> # Available At https://bitbucket.org/octobus/mercurial-devel/
>> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r e6d22ec88946
>> flagutil: introduce a flagprocessorsmixin class
> 
> CC +indygreg
> 
>> diff --git a/mercurial/revlogutils/flagutil.py b/mercurial/revlogutils/flagutil.py
>> --- a/mercurial/revlogutils/flagutil.py
>> +++ b/mercurial/revlogutils/flagutil.py
>> @@ -78,3 +78,74 @@ def insertflagprocessor(flag, processor,
>>           msg = _("cannot register multiple processors on flag '%#x'.") % (flag)
>>           raise error.Abort(msg)
>>       flagprocessors[flag] = processor
>> +
>> +class flagprocessorsmixin(object):
>> +    """basic mixin to support revlog flag processing
>> +
>> +    Make sure the `_flagprocessors` attribute is set at ``__init__`` time.
> 
> I feel a plain function taking (revlog, flagprocessors, ...) is simpler
> than the mixin class which implicitly depends on revlog attributes. But
> maybe I'm biased. I don't like class inheritance in general.

Are you suggesting (revlog, currently_supported_flags, …)? If so, I am 
afraid this would lead to wrong API usage. It is important that the 
revlog bear the supported flags to help enforcing extension/config 
isolation. Maybe we could still use an external function but still rely 
on the attribute ?

In all case, can we move forward with this series and adjust in a follow 
up, I have a lot of other changes waiting on this ?


-- 
Pierre-Yves David