Commit 9e8dfad0 authored by John Snow's avatar John Snow Committed by Max Reitz
Browse files

event_match: always match on None value 



Before, event_match didn't always recurse if the event value was not a
dictionary, and would instead check for equality immediately.

By delaying equality checking to post-recursion, we can allow leaf
values like "5" to match "None" and take advantage of the generic
None-returns-True clause.

This makes the matching a little more obviously consistent at the
expense of being able to check for explicit None values, which is
probably not that important given what this function is used for.

Signed-off-by: default avatarJohn Snow <jsnow@redhat.com>
Message-id: 20190528183857.26167-1-jsnow@redhat.com
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent ba7704f2

python/qemu/__init__.py

+14 −10
Original line number Diff line number Diff line
@@ -409,27 +409,31 @@ class QEMUMachine(object): 


        The match criteria takes the form of a matching subdict. The event is

        checked to be a superset of the subdict, recursively, with matching

        values whenever those values are not None.

        values whenever the subdict values are not None.



        This has a limitation that you cannot explicitly check for None values.



        Examples, with the subdict queries on the left:

         - None matches any object.

         - {"foo": None} matches {"foo": {"bar": 1}}

         - {"foo": {"baz": None}} does not match {"foo": {"bar": 1}}

         - {"foo": {"baz": 2}} matches {"foo": {"bar": 1, "baz": 2}}

         - {"foo": None} matches {"foo": 5}

         - {"foo": {"abc": None}} does not match {"foo": {"bar": 1}}

         - {"foo": {"rab": 2}} matches {"foo": {"bar": 1, "rab": 2}}

        """

        if match is None:

            return True



        try:

            for key in match:

                if key in event:

                if isinstance(event[key], dict):

                    if not QEMUMachine.event_match(event[key], match[key]):

                        return False

                elif event[key] != match[key]:

                    return False

                else:

                    return False

            return True

        except TypeError:

            # either match or event wasn't iterable (not a dict)

            return match == event



    def event_wait(self, name, timeout=60.0, match=None):

        """