hgext/narrow/narrowpatch.py

changegroup: differentiate between fulltext and diff based deltas

Previously, revisiondelta encoded a delta and an optional prefix
containing a delta header. The underlying code could populate
the delta with either a real delta or a fulltext revision.

Following the theme of wanting to defer serialization of revision
data to the changegroup format as long as possible, it seems
prudent for the revision delta instance to capture what type of
data is being represented. This could possibly allow us to
encode revision data differently in the future. But for the
short term, it makes the behavior of a revisiondelta more
explicit.

Differential Revision: https://phab.mercurial-scm.org/D4213

# narrowpatch.py - extensions to mercurial patch module to support narrow clones
#
# Copyright 2017 Google, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from mercurial import (
    extensions,
    patch,
)

def setup(repo):
    def _filepairs(orig, *args):
        """Only includes files within the narrow spec in the diff."""
        narrowmatch = repo.narrowmatch()
        if not narrowmatch.always():
            for x in orig(*args):
                f1, f2, copyop = x
                if ((not f1 or narrowmatch(f1)) and
                    (not f2 or narrowmatch(f2))):
                    yield x
        else:
            for x in orig(*args):
                yield x

    def trydiff(orig, repo, revs, ctx1, ctx2, modified, added, removed,
                copy, getfilectx, *args, **kwargs):
        narrowmatch = repo.narrowmatch()
        if not narrowmatch.always():
            modified = [f for f in modified if narrowmatch(f)]
            added = [f for f in added if narrowmatch(f)]
            removed = [f for f in removed if narrowmatch(f)]
            copy = {k: v for k, v in copy.iteritems() if narrowmatch(k)}
        return orig(repo, revs, ctx1, ctx2, modified, added, removed, copy,
                    getfilectx, *args, **kwargs)

    extensions.wrapfunction(patch, '_filepairs', _filepairs)
    extensions.wrapfunction(patch, 'trydiff', trydiff)