rust-cpython: bindings for MissingAncestors
The exposition is rather straightforward, except for the
remove_ancestors_from() method, which forces us to an inefficient
conversion between Python sets and Rust HashSets.
Two alternatives are proposed in comments:
- changing the inner API to "emit" the revision numbers to discard
this would be a substantial change, and it would be better only in the
cases where there are more to retain than to discard
- mutating the Python set directly: this would force us to define an abstract
`RevisionSet` trait, and implement it both for plain `HashSet` and for
a struct enclosing a Python set with the GIL marker `Python<'p>`, also a non
trivial effort.
The main (and seemingly only) caller of this method being
`mercurial.setdiscovery`, which is currently undergoing serious refactoring,
it's not clear whether these improvements would be worth the effort right now,
so we're leaving it as-is.
Also, in `get_bases()` (will also be used by `setdiscovery`), we'd prefer
to build a Python set directly, but we resort to returning a tuple, waiting
to hear back from our PR onto rust-cpython about that
Differential Revision: https://phab.mercurial-scm.org/D5550
#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# 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
import os
import sys
if os.environ.get('HGUNICODEPEDANTRY', False):
try:
reload(sys)
sys.setdefaultencoding("undefined")
except NameError:
pass
libdir = '@LIBDIR@'
if libdir != '@' 'LIBDIR' '@':
if not os.path.isabs(libdir):
libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
libdir)
libdir = os.path.abspath(libdir)
sys.path.insert(0, libdir)
from hgdemandimport import tracing
with tracing.log('hg script'):
# enable importing on demand to reduce startup time
try:
if sys.version_info[0] < 3 or sys.version_info >= (3, 6):
import hgdemandimport; hgdemandimport.enable()
except ImportError:
sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
' '.join(sys.path))
sys.stderr.write("(check your install and PYTHONPATH)\n")
sys.exit(-1)
from mercurial import dispatch
dispatch.run()