platypush/platypush/plugins/__init__.py
Fabio Manganiello 8378bee7c6 Refactored AssistantEvent.
`AssistantEvent.assistant` is now modelled as an opaque object that
behaves the following way:

- The underlying plugin name is saved under `event.args['_assistant']`.

- `event.assistant` is a property that returns the assistant instance
  via `get_plugin`.

- `event.assistant` is reported as a string (plugin qualified name) upon
  event dump.

This allows event hooks to easily use `event.assistant` to interact with
the underlying assistant and easily modify the conversation flow, while
event hook conditions can still be easily modelled as equality
operations between strings.
2024-05-02 00:51:09 +00:00

341 lines
10 KiB
Python

import asyncio
import logging
import threading
import warnings
from abc import ABC, abstractmethod
from functools import wraps
from typing import Any, Callable, Optional
from platypush.bus import Bus
from platypush.common import ExtensionWithManifest
from platypush.event import EventGenerator
from platypush.message.response import Response
from platypush.utils import get_decorators, get_plugin_name_by_class
PLUGIN_STOP_TIMEOUT = 5 # Plugin stop timeout in seconds
_logger = logging.getLogger(__name__)
def action(f: Callable[..., Any]) -> Callable[..., Response]:
"""
Decorator used to wrap the methods in the plugin classes that should be
exposed as actions.
It wraps the method's response into a generic
:meth:`platypush.message.response.Response` object.
"""
@wraps(f)
def _execute_action(*args, **kwargs) -> Response:
response = Response()
try:
result = f(*args, **kwargs)
except Exception as e:
if isinstance(e, KeyboardInterrupt):
return response
_logger.exception(e)
result = Response(errors=[str(e)])
if result and isinstance(result, Response):
result.errors = (
result.errors if isinstance(result.errors, list) else [result.errors]
)
response = result
elif isinstance(result, tuple) and len(result) == 2:
response.errors = result[1] if isinstance(result[1], list) else [result[1]]
if len(response.errors) == 1 and response.errors[0] is None:
response.errors = []
response.output = result[0]
else:
response = Response(output=result, errors=[])
return response
# Propagate the docstring
_execute_action.__doc__ = f.__doc__
# Expose the wrapped function
_execute_action.wrapped = f # type: ignore
return _execute_action
class Plugin(EventGenerator, ExtensionWithManifest): # lgtm [py/missing-call-to-init]
"""Base plugin class"""
def __init__(self, **kwargs):
super().__init__()
self.logger = logging.getLogger(
'platypush:plugin:' + get_plugin_name_by_class(self.__class__)
)
if 'logging' in kwargs:
self.logger.setLevel(getattr(logging, kwargs['logging'].upper()))
self.registered_actions = set(
get_decorators(self.__class__, climb_class_hierarchy=True).get('action', [])
)
@property
def _db(self):
"""
:return: The reference to the :class:`platypush.plugins.db.DbPlugin`.
"""
from platypush.context import get_plugin
from platypush.plugins.db import DbPlugin
db: DbPlugin = get_plugin(DbPlugin) # type: ignore
assert db, 'db plugin not initialized'
return db
@property
def _redis(self):
"""
:return: The reference to the :class:`platypush.plugins.redis.RedisPlugin`.
"""
from platypush.context import get_plugin
from platypush.plugins.redis import RedisPlugin
redis: RedisPlugin = get_plugin(RedisPlugin) # type: ignore
assert redis, 'db plugin not initialized'
return redis
@property
def _bus(self):
"""
:return: The reference to the :class:`platypush.bus.Bus`.
"""
from platypush.context import get_bus
return get_bus()
@property
def _entities(self):
"""
:return: The reference to the :class:`platypush.plugins.entities.EntitiesPlugin`.
"""
from platypush.context import get_plugin
from platypush.plugins.entities import EntitiesPlugin
entities: EntitiesPlugin = get_plugin('entities') # type: ignore
assert entities, 'entities plugin not initialized'
return entities
def __str__(self):
"""
:return: The qualified name of the plugin.
"""
return get_plugin_name_by_class(self.__class__)
def run(self, method, *args, **kwargs):
assert (
method in self.registered_actions
), f'{method} is not a registered action on {self.__class__.__name__}'
return getattr(self, method)(*args, **kwargs)
class RunnablePlugin(Plugin):
"""
Class for runnable plugins - i.e. plugins that have a start/stop method and can be started.
"""
def __init__(
self,
poll_interval: Optional[float] = 15,
stop_timeout: Optional[float] = PLUGIN_STOP_TIMEOUT,
disable_monitor: bool = False,
**kwargs,
):
"""
:param poll_interval: How often the :meth:`.loop` function should be
executed (default: 15 seconds). *NOTE*: For back-compatibility
reasons, the `poll_seconds` argument is also supported, but it's
deprecated.
:param stop_timeout: How long we should wait for any running
threads/processes to stop before exiting (default: 5 seconds).
:param disable_monitor: If set to True then the plugin will not monitor
for new events. This is useful if you want to run a plugin in
stateless mode and only leverage its actions, without triggering any
events. Defaults to False.
"""
super().__init__(**kwargs)
self.poll_interval = poll_interval
self.bus: Optional[Bus] = None
self.disable_monitor = disable_monitor
self._should_stop = threading.Event()
self._stop_timeout = stop_timeout
self._thread: Optional[threading.Thread] = None
if kwargs.get('poll_seconds') is not None:
warnings.warn(
'poll_seconds is deprecated, use poll_interval instead',
DeprecationWarning,
stacklevel=2,
)
if self.poll_interval is None:
self.poll_interval = kwargs['poll_seconds']
def main(self):
"""
Implementation of the main loop of the plugin.
"""
raise NotImplementedError()
def should_stop(self) -> bool:
return self._should_stop.is_set()
def wait_stop(self, timeout=None):
"""
Wait until a stop event is received.
"""
if self.disable_monitor:
# Wait indefinitely if the monitor is disabled
return self._should_stop.wait(timeout=None)
return self._should_stop.wait(timeout=timeout)
def start(self):
"""
Start the plugin.
"""
self._thread = threading.Thread(
target=self._runner, name=self.__class__.__name__
)
self._thread.start()
def stop(self):
"""
Stop the plugin.
"""
self._should_stop.set()
if (
self._thread
and self._thread != threading.current_thread()
and self._thread.is_alive()
):
self.logger.info('Waiting for the plugin to stop')
try:
if self._thread:
self._thread.join(timeout=self._stop_timeout)
if self._thread and self._thread.is_alive():
self.logger.warning(
'Timeout (seconds=%s) on exit for the plugin',
self._stop_timeout,
)
except Exception as e:
self.logger.warning('Could not join thread on stop: %s', e)
self.logger.info(
'Stopped plugin: [%s]', get_plugin_name_by_class(self.__class__)
)
def _runner(self):
"""
Implementation of the runner thread.
"""
if self.disable_monitor:
return
self.logger.info(
'Starting plugin: [%s]', get_plugin_name_by_class(self.__class__)
)
while not self.should_stop():
try:
self.main()
except Exception as e:
self.logger.exception(e)
if self.poll_interval:
self.wait_stop(self.poll_interval)
self._thread = None
class AsyncRunnablePlugin(RunnablePlugin, ABC):
"""
Class for runnable plugins with an asynchronous event loop attached.
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._loop: Optional[asyncio.AbstractEventLoop] = asyncio.new_event_loop()
self._task: Optional[asyncio.Task] = None
@property
def _should_start_runner(self):
"""
This property is used to determine if the runner and the event loop
should be started for this plugin.
"""
return True
@abstractmethod
async def listen(self):
"""
Main body of the async plugin. When it's called, the event loop should
already be running and available over `self._loop`.
"""
async def _listen(self):
"""
Wrapper for :meth:`.listen` that catches any exceptions and logs them.
"""
try:
await self.listen()
except KeyboardInterrupt:
pass
except RuntimeError as e:
if not (
str(e).startswith('Event loop stopped before ')
or str(e).startswith('no running event loop')
):
raise e
def _run_listener(self):
"""
Initialize an event loop and run the listener as a task.
"""
assert self._loop, 'The loop is not initialized'
asyncio.set_event_loop(self._loop)
self._task = self._loop.create_task(self._listen())
if hasattr(self._task, 'set_name'):
self._task.set_name(self.__class__.__name__ + '.listen')
try:
self._loop.run_until_complete(self._task)
except Exception as e:
if not self.should_stop():
self.logger.warning('The loop has terminated with an error')
self.logger.exception(e)
self._task.cancel()
def main(self):
if self.should_stop():
self.logger.info('The plugin is already scheduled to stop')
return
self._loop = asyncio.new_event_loop()
if self._should_start_runner:
while not self.should_stop():
try:
self._run_listener()
finally:
self.wait_stop(self.poll_interval)
else:
self.wait_stop()
def stop(self):
if self._loop and self._loop.is_running():
self._loop.call_soon_threadsafe(self._loop.stop)
self._loop = None
super().stop()
# vim:sw=4:ts=4:et: