[PATCH 1 of 9 V3] obsolete: introduce a _succs class

[Denis Laxalde]

Boris Feld a écrit :
> # HG changeset patch
> # User Boris Feld <boris.feld at octobus.net>
> # Date 1499036035 -7200
> #      Mon Jul 03 00:53:55 2017 +0200
> # Node ID 328789121fa66b99c50ffa2fb139df700cf9fdc8
> # Parent  3cfc9070245fbaa8c4c010327f24d579a416370f
> # EXP-Topic obsfatetemplate
> obsolete: introduce a _succs class
> 
> It will be useful later when we will be adding markers to _succs in order to
> represent a successorset with the list of markers from the root to each
> successors sets. This information will be needed for the obsfate template I will
> introduce.
> 
> Makes it a subclass of list so all callers will continue to work.
> 
> diff -r 3cfc9070245f -r 328789121fa6 mercurial/obsutil.py
> --- a/mercurial/obsutil.py	Wed Aug 16 10:44:06 2017 -0700
> +++ b/mercurial/obsutil.py	Mon Jul 03 00:53:55 2017 +0200
> @@ -327,6 +327,9 @@
>               obsoleted.add(rev)
>       return obsoleted
>   
> +class _succs(list):
> +    """small class to represent a successors with some metadata about it"""
> +
>   def successorssets(repo, initialnode, closest=False, cache=None):
>       """Return set of all latest successors of initial nodes
>   
> @@ -445,11 +448,11 @@
>               # case (2): end of walk.
>               if current in repo:
>                   # We have a valid successors.
> -                cache[current] = [(current,)]
> +                cache[current] = [_succs((current,))]
>               else:
>                   # Final obsolete version is unknown locally.
>                   # Do not count that as a valid successors
> -                cache[current] = []
> +                cache[current] = _succs()

While equivalent by value (at this point), it seems to me that this
should be kept as an empty list in "else" case (to keep
`type(cache[current]) == list`).

>           else:
>               # cases (3) and (4)
>               #
> @@ -487,7 +490,7 @@
>                       if suc not in cache:
>                           if suc in stackedset:
>                               # cycle breaking
> -                            cache[suc] = []
> +                            cache[suc] = _succs()
>                           else:
>                               # case (3) If we have not computed successors sets
>                               # of one of those successors we add it to the
> @@ -521,13 +524,13 @@
>                   succssets = []
>                   for mark in sorted(succmarkers[current]):
>                       # successors sets contributed by this marker
> -                    markss = [[]]
> +                    markss = [_succs()]
>                       for suc in mark[1]:
>                           # cardinal product with previous successors
>                           productresult = []
>                           for prefix in markss:
>                               for suffix in cache[suc]:
> -                                newss = list(prefix)
> +                                newss = _succs(prefix)
>                                   for part in suffix:
>                                       # do not duplicated entry in successors set
>                                       # first entry wins.