As a convenience. It isn't used by the library itself, but it is used by
the test suite. It will also come in handy for users of the library
still on Python 3.6.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-23-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This is added in anticipation of wanting it for a synchronous wrapper
for the iotest interface. Normally, execute() and execute_msg() both
raise QMP errors in the form of Python exceptions.
Many iotests expect the entire reply as-is. To reduce churn there, add a
private execution interface that will ease transition churn. However, I
do not wish to encourage its use, so it will remain a private interface.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-22-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Add execute() and execute_msg().
_execute() is split into _issue() and _reply() halves so that
hypothetical subclasses of QMP that want to support different execution
paradigms can do so.
I anticipate a synchronous interface may have need of separating the
send/reply phases. However, I do not wish to expose that interface here
and want to actively discourage it, so they remain private interfaces.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-21-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
mypy handles this better -- but we only need the workaround because
pylint under Python 3.6 does not understand that a MutableMapping really
does have a .get() method attached.
We could remove this again once 3.7 is our minimum.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-19-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
The star of our show!
Add most of the QMP protocol, sans support for actually executing
commands. No problem, that happens in the next several commits.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-18-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
too-many-function-args seems prone to failure when considering
things like Method Resolution Order, which mypy gets correct. When
dealing with multiple inheritance, pylint doesn't seem to understand
which method will actually get called, while mypy does.
Remove the less powerful, redundant check.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-17-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This class was designed as a "mix-in" primarily so that the feature
could be given its own treatment in its own python module.
It gets quite a bit too long otherwise.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-16-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
The QMP spec doesn't define very many objects that are iron-clad in
their format, but there are a few. This module makes it trivial to
validate them without relying on an external third-party library.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-15-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
The Message class is here primarily to serve as a solid type to use for
mypy static typing for unambiguous annotation and documentation.
We can also stuff JSON serialization and deserialization into this class
itself so it can be re-used even outside this infrastructure.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-14-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This is added as a courtesy: many protocols are line-based, including
QMP. Putting it in AsyncProtocol lets us keep the QMP class
implementation just a pinch more abstract.
(And, if we decide to add a QTEST implementation later, it will need
this, too. (Yes, I have a QTEST implementation.))
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-13-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Add hooks designed to log/filter incoming/outgoing messages. The primary
intent for these is to be able to support iotests which may want to log
messages with specific filters for reproducible output.
Another use is for plugging into Urwid frameworks; all messages in/out
can be automatically added to a rendering list for the purposes of a
qmp-shell like tool.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-12-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This serves a few purposes:
1. Protect interfaces when it's not safe to call them (via @require)
2. Add an interface by which an async client can determine if the state
has changed, for the purposes of connection management.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-7-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This is the bare minimum that you need to establish a full-duplex async
message-based protocol with Python's asyncio.
The features to be added in forthcoming commits are:
- Runstate tracking
- Logging
- Support for incoming connections via accept()
- _cb_outbound, _cb_inbound message hooks
- _readline() method
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Python 3.6 does not have all of the goodies that Python 3.7 does, and we
need to support both. Add some compatibility wrappers needed for this
purpose.
(Note: Python 3.6 is EOL December 2021.)
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
A few new annoyances. Of note is the new warning for an unspecified
encoding when opening a text file, which actually does indicate a
potentially real problem; see
https://www.python.org/dev/peps/pep-0597/#motivation
Use LC_CTYPE to determine an encoding to use for interpreting QEMU's
terminal output. Note that Python states: "language code and encoding
may be None if their values cannot be determined" -- use a platform
default as a backup.
Notes: Passing encoding=None will generate a suppressed warning on
Python 3.10+ that 'None' should not be passed as the encoding
argument. This behavior may be deprecated in the future and the default
switched to be a ubiquitous UTF-8. Opting in to the locale default will
be done by passing the encoding 'locale', but that isn't available in
3.6 through 3.9. Presumably this warning will be unsuppressed some time
prior to the actual switch and we can re-investigate these issues at
that time if necessary.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-id: 20210916182248.721529-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
John Snow
Vladimir Sementsov-OgievskiyandHanna Reitz