[PATCH 2 of 2] commands: allow debugobsolete to delete arbitrary obsmarkers

[Pierre-Yves David]

On 04/01/2016 08:56 AM, Kostia Balytskyi wrote:
> # HG changeset patch
> # User Kostia Balytskyi <ikostia at fb.com>
> # Date 1459525644 25200
> #      Fri Apr 01 08:47:24 2016 -0700
> # Node ID ff46f27e8fca7b726cc042eb745e54a3bc9dbe39
> # Parent  d4fc1ec31c6666d85eb2e8c174f6c231546ad8fd
> commands: allow debugobsolete to delete arbitrary obsmarkers
>
> Sample usage is:
>    '$ hg debugobsolete --delete 0 5'
>
> This is a debug feature that will help people working on evolution and
> obsolescense.
>
> diff --git a/mercurial/commands.py b/mercurial/commands.py
> --- a/mercurial/commands.py
> +++ b/mercurial/commands.py
> @@ -3046,6 +3046,7 @@ def debuglocks(ui, repo, **opts):
>             _('record parent information for the precursor')),
>            ('r', 'rev', [], _('display markers relevant to REV')),
>            ('', 'index', False, _('display index of the marker')),
> +         ('', 'delete', [], _('delete markers specified by indices')),
>           ] + commitopts2,
>            _('[OBSOLETED [REPLACEMENT ...]]'))
>   def debugobsolete(ui, repo, precursor=None, *successors, **opts):
> @@ -3066,6 +3067,16 @@ def debugobsolete(ui, repo, precursor=No
>               raise error.Abort('changeset references must be full hexadecimal '
>                                'node identifiers')
>
> +    if opts.get('delete'):
> +        try:
> +            indices = [int(v) for v in opts.get('delete')]
> +        except ValueError:
> +            raise error.Abort(_('invalid index value'),
> +                              hint=_('use integers fro indices'))
> +        n = repo.obsstore.delete(indices)

We'll want some locking around this to prevent other process reading the 
repository to misbehave.

> +        ui.write(_('Deleted %i obsolescense markers\n') % n)
> +        return
> +
>       if precursor is not None:
>           if opts['rev']:
>               raise error.Abort('cannot select revision when creating marker')
> diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
> --- a/mercurial/obsolete.py
> +++ b/mercurial/obsolete.py
> @@ -633,6 +633,30 @@ class obsstore(object):
>           transaction.hookargs['new_obsmarkers'] = str(previous + len(new))
>           return len(new)
>
> +    def delete(self, indices):
> +        """Delete some obsmarkers from store and return the number of them
> +
> +        Indices is a list of ints which are the indices
> +        of the markers to be deleted."""
> +        if not indices:
> +            # we don't want to rewrite the obsstore with the same content
> +            return
> +
> +        left = []
> +        current = self._all
> +        n = 0
> +        for i, m in enumerate(current):
> +            if i in indices:
> +                n += 1
> +                continue
> +            left.append(m)
> +
> +        newobsstore = self.svfs('obsstore', 'w', atomictemp=True)
> +        for bytes in encodemarkers(left, True, self._version):
> +            newobsstore.write(bytes)
> +        newobsstore.close()
> +        return n
> +

We probably want to have this somewhat collaborating with the 
transaction, like mercurial.repair.strip do. At least we want to ensure 
we are not in a transaction before butchering the obstore.

(and that we are locked)

>       def mergemarkers(self, transaction, data):
>           """merge a binary stream of markers inside the obsstore


-- 
Pierre-Yves David