[PATCH 6 of 9] flagutil: introduce a flagprocessorsmixin class

[Pierre-Yves David]

On 8/11/19 1:35 AM, Gregory Szorc wrote:
> On Wed, Aug 7, 2019 at 7:18 PM Pierre-Yves David 
> <pierre-yves.david at ens-lyon.org <mailto:pierre-yves.david at ens-lyon.org>> 
> wrote:
> 
>     # HG changeset patch
>     # User Pierre-Yves David <pierre-yves.david at octobus.net
>     <mailto:pierre-yves.david at octobus.net>>
>     # Date 1565219568 -7200
>     #      Thu Aug 08 01:12:48 2019 +0200
>     # Node ID 466943d2fed3602e08ac9117afef1c727bcb98a5
>     # Parent  82e7f9d4d0bac574e4aa1b8f81e81ac1df3f6ddc
>     # EXP-Topic flag-processors
>     # Available At https://bitbucket.org/octobus/mercurial-devel/
>     #              hg pull
>     https://bitbucket.org/octobus/mercurial-devel/ -r 466943d2fed3
>     flagutil: introduce a flagprocessorsmixin class
> 
>     To avoid code duplication, we will provide a simple "ready to use"
>     mixin that
>     carry the appropriate logic. First we use it in standard revlog,
>     we'll remove
>     code duplication in later changesets.
> 
>     diff --git a/mercurial/revlog.py b/mercurial/revlog.py
>     --- a/mercurial/revlog.py
>     +++ b/mercurial/revlog.py
>     @@ -259,7 +259,7 @@ class revlogio(object):
>                   p = versionformat_pack(version) + p[4:]
>               return p
> 
>     -class revlog(object):
>     +class revlog(flagutil.flagprocessorsmixin):
>           """
>           the underlying revision storage object
> 
>     @@ -1682,69 +1682,6 @@ class revlog(object):
>               """
>               return storageutil.hashrevisionsha1(text, p1, p2)
> 
>     -    def _processflags(self, text, flags, operation, raw=False):
>     -        """Inspect revision data flags and applies transforms
>     defined by
>     -        registered flag processors.
>     -
>     -        ``text`` - the revision data to process
>     -        ``flags`` - the revision flags
>     -        ``operation`` - the operation being performed (read or write)
>     -        ``raw`` - an optional argument describing if the raw
>     transform should be
>     -        applied.
>     -
>     -        This method processes the flags in the order (or reverse
>     order if
>     -        ``operation`` is 'write') defined by REVIDX_FLAGS_ORDER,
>     applying the
>     -        flag processors registered for present flags. The order of
>     flags defined
>     -        in REVIDX_FLAGS_ORDER needs to be stable to allow
>     non-commutativity.
>     -
>     -        Returns a 2-tuple of ``(text, validatehash)`` where
>     ``text`` is the
>     -        processed text and ``validatehash`` is a bool indicating
>     whether the
>     -        returned text should be checked for hash integrity.
>     -
>     -        Note: If the ``raw`` argument is set, it has precedence
>     over the
>     -        operation and will only update the value of ``validatehash``.
>     -        """
>     -        # fast path: no flag processors will run
>     -        if flags == 0:
>     -            return text, True
>     -        if not operation in ('read', 'write'):
>     -            raise error.ProgrammingError(_("invalid '%s' operation") %
>     -                                         operation)
>     -        # Check all flags are known.
>     -        if flags & ~flagutil.REVIDX_KNOWN_FLAGS:
>     -            raise error.RevlogError(_("incompatible revision flag
>     '%#x'") %
>     -                                    (flags &
>     ~flagutil.REVIDX_KNOWN_FLAGS))
>     -        validatehash = True
>     -        # Depending on the operation (read or write), the order
>     might be
>     -        # reversed due to non-commutative transforms.
>     -        orderedflags = REVIDX_FLAGS_ORDER
>     -        if operation == 'write':
>     -            orderedflags = reversed(orderedflags)
>     -
>     -        for flag in orderedflags:
>     -            # If a flagprocessor has been registered for a known
>     flag, apply the
>     -            # related operation transform and update result tuple.
>     -            if flag & flags:
>     -                vhash = True
>     -
>     -                if flag not in self._flagprocessors:
>     -                    message = _("missing processor for flag '%#x'")
>     % (flag)
>     -                    raise error.RevlogError(message)
>     -
>     -                processor = self._flagprocessors[flag]
>     -                if processor is not None:
>     -                    readtransform, writetransform, rawtransform =
>     processor
>     -
>     -                    if raw:
>     -                        vhash = rawtransform(self, text)
>     -                    elif operation == 'read':
>     -                        text, vhash = readtransform(self, text)
>     -                    else: # write operation
>     -                        text, vhash = writetransform(self, text)
>     -                validatehash = validatehash and vhash
>     -
>     -        return text, validatehash
>     -
>           def checkhash(self, text, node, p1=None, p2=None, rev=None):
>               """Check node hash integrity.
> 
>     diff --git a/mercurial/revlogutils/flagutil.py
>     b/mercurial/revlogutils/flagutil.py
>     --- a/mercurial/revlogutils/flagutil.py
>     +++ b/mercurial/revlogutils/flagutil.py
>     @@ -78,3 +78,90 @@ def insertflagprocessor(flag, processor,
>               msg = _("cannot register multiple processors on flag
>     '%#x'.") % (flag)
>               raise error.Abort(msg)
>           flagprocessors[flag] = processor
>     +
>     +# Flag processors for REVIDX_ELLIPSIS.
>     +def ellipsisreadprocessor(rl, text):
>     +    return text, False
>     +
>     +def ellipsiswriteprocessor(rl, text):
>     +    return text, False
>     +
>     +def ellipsisrawprocessor(rl, text):
>     +    return False
>     +
>     +ellipsisprocessor = (
>     +    ellipsisreadprocessor,
>     +    ellipsiswriteprocessor,
>     +    ellipsisrawprocessor,
>     +)
> 
> 
> Is the addition of the ellipsis flag processor intentional for this commit?

It is not, I'll clean that up and send a V2.

-- 
Pierre-Yves David