Commit graph

14 commits

Author SHA1 Message Date
John Snow 6e7751dc38 python/aqmp: rename AQMPError to QMPError
This is in preparation for renaming qemu.aqmp to qemu.qmp. I should have
done this from this from the very beginning, but it's a convenient time
to make sure this churn is taken care of.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2022-01-21 16:01:31 -05:00
John Snow 728dcac5e3 python/aqmp: add SocketAddrT to package root
It's a commonly needed definition, it can be re-exported by the root.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Beraldo Leal <bleal@redhat.com>
2022-01-21 16:01:31 -05:00
John Snow dc6877bd2e python/aqmp: fix docstring typo
Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Beraldo Leal <bleal@redhat.com>
2022-01-21 16:01:31 -05:00
John Snow 0f71c9a936 python/aqmp: Remove scary message
The scary message interferes with the iotests output. Coincidentally, if
iotests works by removing this, then it's good evidence that we don't
really need to scare people away from using it.

Signed-off-by: John Snow <jsnow@redhat.com>
Acked-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-id: 20211026175612.4127598-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-11-01 11:54:59 -04:00
John Snow 3a3d84f5ec python/aqmp: Disable logging messages by default
AQMP is a library, and ideally it should not print error diagnostics
unless a user opts into seeing them. By default, Python will print all
WARNING, ERROR or CRITICAL messages to screen if no logging
configuration has been created by a client application.

In AQMP's case, ERROR logging statements are used to report additional
detail about runtime failures that will also eventually be reported to the
client library via an Exception, so these messages should not be
rendered by default.

(Why bother to have them at all, then? In async contexts, there may be
multiple Exceptions and we are only able to report one of them back to
the client application. It is not reasonably easy to predict ahead of
time if one or more of these Exceptions will be squelched. Therefore,
it's useful to log intermediate failures to help make sense of the
ultimate, resulting failure.)

Add a NullHandler that will suppress these messages until a client
application opts into logging via logging.basicConfig or similar. Note
that upon calling basicConfig(), this handler will *not* suppress these
messages from being displayed by the client's configuration.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210923004938.3999963-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-10-12 12:22:11 -04:00
John Snow ed6d4d7a95 python/aqmp: add scary message
Add a warning whenever AQMP is used to steer people gently away from
using it for the time-being.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-24-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow e0fea0b3ac python/aqmp: add execute() interfaces
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>
2021-09-27 12:10:29 -04:00
John Snow c67d696b85 python/aqmp: add QMP protocol support
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>
2021-09-27 12:10:29 -04:00
John Snow b3cda213a7 python/aqmp: add QMP event support
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>
2021-09-27 12:10:29 -04:00
John Snow 08f98a2231 python/aqmp: add QMP Message format
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>
2021-09-27 12:10:29 -04:00
John Snow c58b42e095 python/aqmp: add runstate state machine to AsyncProtocol
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>
2021-09-27 12:10:29 -04:00
John Snow 4ccaab0377 python/aqmp: add generic async message-based protocol support
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>
2021-09-27 12:10:29 -04:00
John Snow fbfb6a37a3 python/aqmp: add error classes
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:29 -04:00
John Snow a093a65567 python/aqmp: add asynchronous QMP (AQMP) subpackage
For now, it's empty! Soon, it won't be.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20210915162955.333025-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-09-27 12:10:27 -04:00