|
| From: | John Snow |
| Subject: | Re: [PATCH v3 04/13] python/aqmp-tui: Add AQMP TUI draft |
| Date: | Thu, 5 Aug 2021 15:11:29 -0400 |
Added a draft of AQMP TUI.
Implements the follwing basic features:
1) Command transmission/reception.
2) Shows events asynchronously.
3) Shows server status in the bottom status bar.
Also added necessary pylint, mypy configurations
Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
---
python/qemu/aqmp/aqmp_tui.py | 333 +++++++++++++++++++++++++++++++++++
python/setup.cfg | 16 +-
2 files changed, 348 insertions(+), 1 deletion(-)
create mode 100644 python/qemu/aqmp/aqmp_tui.py
diff --git a/python/qemu/aqmp/aqmp_tui.py b/python/qemu/aqmp/aqmp_tui.py
new file mode 100644
index 0000000000..ec9eba0aa7
--- /dev/null
+++ b/python/qemu/aqmp/aqmp_tui.py
@@ -0,0 +1,333 @@
+# Copyright (c) 2021
+#
+# Authors:
+# Niteesh Babu G S <niteesh.gs@gmail.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or
+# later. See the COPYING file in the top-level directory.
+
+import argparse
+import asyncio
+import logging
+from logging import Handler
+import signal
+
+import urwid
+import urwid_readline
+
+from ..qmp import QEMUMonitorProtocol, QMPBadPortError
+from .message import DeserializationError, Message, UnexpectedTypeError
+from .protocol import ConnectError
+from .qmp_client import ExecInterruptedError, QMPClient
+from .util import create_task, pretty_traceback
+
+
+UPDATE_MSG = 'UPDATE_MSG'
+
+# Using root logger to enable all loggers under qemu and asyncio
+LOGGER = logging.getLogger()
+
+
+def format_json(msg):
+ """
+ Formats given multiline JSON message into a single line message.
+ Converting into single line is more asthetically pleasing when looking
+ along with error messages compared to multiline JSON.
+ """
+ # FIXME: Use better formatting mechanism. Might break at more complex JSON
+ # data.
+ msg = msg.replace('\n', '')
+ words = msg.split(' ')
+ words = [word for word in words if word != '']
+ return ' '.join(words)
+
+
+class App(QMPClient):
+ def __init__(self, address):
+ urwid.register_signal(type(self), UPDATE_MSG)
+ self.window = Window(self)
+ self.address = address
+ self.aloop = None
+ super().__init__()
+
+ def add_to_history(self, msg):
+ urwid.emit_signal(self, UPDATE_MSG, msg)
+
+ def _cb_outbound(self, msg):
+ # FIXME: I think the ideal way to omit these messages during in-TUI
+ # logging will be to add a filter to the logger. We can use regex to
+ # filter out messages starting with 'Request:' or 'Response:' but I
+ # think a better approach will be encapsulate the message in an object
+ # and filter based on the object. Encapsulation of the message will
+ # also be necessary when we want different formatting of messages
+ # inside TUI.
+ handler = LOGGER.handlers[0]
+ if not isinstance(handler, TUILogHandler):
+ LOGGER.debug('Request: %s', str(msg))
+ self.add_to_history('<-- ' + str(msg))
+ return msg
+
+ def _cb_inbound(self, msg):
+ handler = LOGGER.handlers[0]
+ if not isinstance(handler, TUILogHandler):
+ LOGGER.debug('Response: %s', str(msg))
+ self.add_to_history('--> ' + str(msg))
+ return msg
+
+ async def wait_for_events(self):
+ async for event in self.events:
+ self.handle_event(event)
+
+ async def _send_to_server(self, raw_msg):
+ # FIXME: Format the raw_msg in history view to one line. It is not
+ # pleasing to see multiple lines JSON object with an error statement.
+ try:
+ msg = Message(bytes(raw_msg, encoding='utf-8'))
+ # Format multiline json into a single line JSON, since it is more
+ # pleasing to look along with err message in TUI.
+ raw_msg = self.format_json(raw_msg)
+ await self._raw(msg, assign_id='id' not in msg)
+ except (ValueError, TypeError) as err:
+ LOGGER.info('Invalid message: %s', str(err))
+ self.add_to_history(f'{raw_msg}: {err}')
+ except (DeserializationError, UnexpectedTypeError) as err:
+ LOGGER.info('Invalid message: %s', err.error_message)
+ self.add_to_history(f'{raw_msg}: {err.error_message}')
+ except ExecInterruptedError:
+ LOGGER.info('Error server disconnected before reply')
+ urwid.emit_signal(self, UPDATE_MSG,
+ '{"error": "Server disconnected before reply"}')
+ self._set_status("Server disconnected")
+ except Exception as err:
+ LOGGER.error('Exception from _send_to_server: %s', str(err))
+ raise err
+
+ def cb_send_to_server(self, msg):
+ create_task(self._send_to_server(msg))
+
+ def unhandled_input(self, key):
+ if key == 'esc':
+ self.kill_app()
+
+ def kill_app(self):
+ # TODO: Work on the disconnect logic
+ create_task(self._kill_app())
+
+ async def _kill_app(self):
+ # It is ok to call disconnect even in disconnect state
+ try:
+ await self.disconnect()
+ LOGGER.debug('Disconnect finished. Exiting app')
+ except Exception as err:
+ LOGGER.info('_kill_app: %s', str(err))
+ # Let the app crash after providing a proper stack trace
+ raise err
+ raise urwid.ExitMainLoop()
+
+ def handle_event(self, event):
+ # FIXME: Consider all states present in qapi/run-state.json
+ if event['event'] == 'SHUTDOWN':
+ self._set_status('Server shutdown')
+
+ def _set_status(self, msg: str) -> None:
+ self.window.footer.set_text(msg)
+
+ def _get_formatted_address(self) -> str:
+ addr = f'{self.address}'
+ if isinstance(self.address, tuple):
+ host, port = self.address
+ addr = f'{host}:{port}'
+ return addr
+
+ async def connect_server(self):
+ try:
+ await self.connect(self.address)
+ addr = self._get_formatted_address()
+ self._set_status(f'Connected to {addr}')
+ except ConnectError as err:
+ LOGGER.info('connect_server: ConnectError %s', str(err))
+ self._set_status('Server shutdown')
+
+ def run(self, debug=False):
+ self.aloop = asyncio.get_event_loop()
+ self.aloop.set_debug(debug)
+
+ # Gracefully handle SIGTERM and SIGINT signals
+ cancel_signals = [signal.SIGTERM, signal.SIGINT]
+ for sig in cancel_signals:
+ self.aloop.add_signal_handler(sig, self.kill_app)
+
+ event_loop = urwid.AsyncioEventLoop(loop=self.aloop)
+ main_loop = urwid.MainLoop(urwid.AttrMap(self.window, 'background'),
+ unhandled_input=self.unhandled_input,
+ handle_mouse=True,
+ event_loop=event_loop)
+
+ create_task(self.wait_for_events(), self.aloop)
+ create_task(self.connect_server(), self.aloop)
+ try:
+ main_loop.run()
+ except Exception as err:
+ LOGGER.error('%s\n%s\n', str(err), pretty_traceback())
+ raise err
+
+
+class StatusBar(urwid.Text):
+ """
+ A simple Text widget that currently only shows connection status.
+ """
+ def __init__(self, text=''):
+ super().__init__(text, align='right')
+
+
+class Editor(urwid_readline.ReadlineEdit):
+ """
+ Support urwid_readline features along with
+ history support which lacks in urwid_readline
+ """
+ def __init__(self, master):
+ super().__init__(caption='> ', multiline=True)
+ self.master = master
+ self.history = []
+ self.last_index = -1
+ self.show_history = False
+
+ def keypress(self, size, key):
+ # TODO: Add some logic for down key and clean up logic if possible.
+ # Returning None means the key has been handled by this widget
+ # which otherwise is propogated to the parent widget to be
+ # handled
+ msg = self.get_edit_text()
+ if key == 'up' and not msg:
+ # Show the history when 'up arrow' is pressed with no input text.
+ # NOTE: The show_history logic is necessary because in 'multiline'
+ # mode (which we use) 'up arrow' is used to move between lines.
+ self.show_history = True
+ last_msg = self.history[self.last_index] if self.history else ''
+ self.set_edit_text(last_msg)
+ self.edit_pos = len(last_msg)
+ self.last_index += 1
+ elif key == 'up' and self.show_history:
+ if self.last_index < len(self.history):
+ self.set_edit_text(self.history[self.last_index])
+ self.edit_pos = len(self.history[self.last_index])
+ self.last_index += 1
+ elif key == 'meta enter':
+ # When using multiline, enter inserts a new line into the editor
+ # send the input to the server on alt + enter
+ self.master.cb_send_to_server(msg)
+ self.history.insert(0, msg)
+ self.set_edit_text('')
+ self.last_index = 0
+ self.show_history = False
+ else:
+ self.show_history = False
+ self.last_index = 0
+ return super().keypress(size, key)
+ return None
+
+
+class EditorWidget(urwid.Filler):
+ """
+ Wraps CustomEdit
+ """
+ def __init__(self, master):
+ super().__init__(Editor(master), valign='top')
+
+
+class HistoryBox(urwid.ListBox):
+ """
+ Shows all the QMP message transmitted/received
+ """
+ def __init__(self, master):
+ self.master = master
+ self.history = urwid.SimpleFocusListWalker([])
+ super().__init__(self.history)
+
+ def add_to_history(self, history):
+ self.history.append(urwid.Text(history))
+ if self.history:
+ self.history.set_focus(len(self.history) - 1)
+
+
+class HistoryWindow(urwid.Frame):
+ """
+ Composes the HistoryBox and EditorWidget
+ """
+ def __init__(self, master):
+ self.master = master
+ self.editor_widget = EditorWidget(master)
+ self.editor = urwid.LineBox(self.editor_widget)
+ self.history = HistoryBox(master)
+ self.body = urwid.Pile([('weight', 80, self.history),
+ ('weight', 20, self.editor)])
+ super().__init__(self.body)
+ urwid.connect_signal(self.master, UPDATE_MSG, self.cb_add_to_history)
+
+ def cb_add_to_history(self, msg):
+ self.history.add_to_history(msg)
+
+
+class Window(urwid.Frame):
+ """
+ This is going to be the main window that is going to compose other
+ windows. In this stage it is unnecesssary but will be necessary in
+ future when we will have multiple windows and want to the switch between
+ them and display overlays
+ """
+ def __init__(self, master):
+ self.master = master
+ footer = StatusBar()
+ body = HistoryWindow(master)
+ super().__init__(body, footer=footer)
+
+
+class TUILogHandler(Handler):
+ def __init__(self, tui):
+ super().__init__()
+ self.tui = tui
+
+ def emit(self, record):
+ level = record.levelname
+ msg = record.getMessage()
+ msg = f'[{level}]: {msg}'
+ self.tui.add_to_history(msg)
+
+
+def main():
+ parser = argparse.ArgumentParser(description='AQMP TUI')
+ parser.add_argument('qmp_server', help='Address of the QMP server'
+ '< UNIX socket path | TCP addr:port >')
+ parser.add_argument('--log-file', help='The Log file name')
+ parser.add_argument('--log-level', default='WARNING',
+ help='Log level <CRITICAL|ERROR|WARNING|INFO|DEBUG|>')
+ parser.add_argument('--asyncio-debug', action=""> + help='Enable debug mode for asyncio loop'
+ 'Generates lot of output, makes TUI unusable when'
+ 'logs are logged in the TUI itself.'
+ 'Use only when logging to a file')
+ args = parser.parse_args()
+
+ try:
+ address = QEMUMonitorProtocol.parse_address(args.qmp_server)
+ except QMPBadPortError as err:
+ parser.error(err)
+
+ app = App(address)
+
+ if args.log_file:
+ LOGGER.addHandler(logging.FileHandler(args.log_file))
+ else:
+ LOGGER.addHandler(TUILogHandler(app))
+
+ log_level = logging.getLevelName(args.log_level)
+ # getLevelName returns 'Level {log_level}' when a invalid level is passed.
+ if log_level == f'Level {args.log_level}':
+ parser.error('Invalid log level')
+ LOGGER.setLevel(log_level)
+
+ app.run(args.asyncio_debug)
+
+
+if __name__ == '__main__':
+ main() # type: ignore
diff --git a/python/setup.cfg b/python/setup.cfg
index d106a0ed7a..50f9894468 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -81,8 +81,22 @@ namespace_packages = True
# fusepy has no type stubs:
allow_subclassing_any = True
+[mypy-qemu.aqmp.aqmp_tui]
+disallow_untyped_defs = False
+disallow_incomplete_defs = False
+check_untyped_defs = False
+# urwid and urwid_readline have no type stubs:
+allow_subclassing_any = True
+
+# The following missing import directives are because these libraries do not
+# provide type stubs. Allow them on an as-needed basis for mypy.
[mypy-fuse]
-# fusepy has no type stubs:
+ignore_missing_imports = True
+
+[mypy-urwid]
+ignore_missing_imports = True
+
+[mypy-urwid_readline]
ignore_missing_imports = True
[pylint.messages control]
--
2.17.1
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