mercurial/thirdparty/attr/_compat.py

narrow: only send the narrowspecs back if ACL in play

I am unable to think why we need to send narrowspecs back from the server. The
current state adds a 'narrow:spec' part to each changegroup which is generated
when narrow extension is enabled. So we are sending narrowspecs on pull also.

There is a problem with sending the narrowspecs the way we are doing it right
now. We add include and exclude as parameter of the 'narrow:spec' bundle2 part.
The the len of include or exclude string increase 255 which is obvious while
working on large repos, bundle2 generation code breaks. For more on that refer
issue5952 on bugzilla.

I was thinking why we need to send the narrowspecs back, and deleted the
'narrow:spec' bundle2 part generation code and found that only narrow-acl test
has some failure.

With this patch, we will only send the 'narrow:spec' bundle2 part if ACL is
enabled because the original narrowspecs in those cases can be a subset of
narrowspecs user requested.

There are phase related output change in couple of tests. The output change
shows that we are now dealing in public phases completely. So maybe sending the
narrow:spec bundle2 part was preventing phases being exchanged or phase bundle2
data being applied.

Differential Revision: https://phab.mercurial-scm.org/D4931

from __future__ import absolute_import, division, print_function

import sys
import types


PY2 = sys.version_info[0] == 2


if PY2:
    from UserDict import IterableUserDict

    # We 'bundle' isclass instead of using inspect as importing inspect is
    # fairly expensive (order of 10-15 ms for a modern machine in 2016)
    def isclass(klass):
        return isinstance(klass, (type, types.ClassType))

    # TYPE is used in exceptions, repr(int) is different on Python 2 and 3.
    TYPE = "type"

    def iteritems(d):
        return d.iteritems()

    def iterkeys(d):
        return d.iterkeys()

    # Python 2 is bereft of a read-only dict proxy, so we make one!
    class ReadOnlyDict(IterableUserDict):
        """
        Best-effort read-only dict wrapper.
        """

        def __setitem__(self, key, val):
            # We gently pretend we're a Python 3 mappingproxy.
            raise TypeError("'mappingproxy' object does not support item "
                            "assignment")

        def update(self, _):
            # We gently pretend we're a Python 3 mappingproxy.
            raise AttributeError("'mappingproxy' object has no attribute "
                                 "'update'")

        def __delitem__(self, _):
            # We gently pretend we're a Python 3 mappingproxy.
            raise TypeError("'mappingproxy' object does not support item "
                            "deletion")

        def clear(self):
            # We gently pretend we're a Python 3 mappingproxy.
            raise AttributeError("'mappingproxy' object has no attribute "
                                 "'clear'")

        def pop(self, key, default=None):
            # We gently pretend we're a Python 3 mappingproxy.
            raise AttributeError("'mappingproxy' object has no attribute "
                                 "'pop'")

        def popitem(self):
            # We gently pretend we're a Python 3 mappingproxy.
            raise AttributeError("'mappingproxy' object has no attribute "
                                 "'popitem'")

        def setdefault(self, key, default=None):
            # We gently pretend we're a Python 3 mappingproxy.
            raise AttributeError("'mappingproxy' object has no attribute "
                                 "'setdefault'")

        def __repr__(self):
            # Override to be identical to the Python 3 version.
            return "mappingproxy(" + repr(self.data) + ")"

    def metadata_proxy(d):
        res = ReadOnlyDict()
        res.data.update(d)  # We blocked update, so we have to do it like this.
        return res

else:
    def isclass(klass):
        return isinstance(klass, type)

    TYPE = "class"

    def iteritems(d):
        return d.items()

    def iterkeys(d):
        return d.keys()

    def metadata_proxy(d):
        return types.MappingProxyType(dict(d))