docstrings and full test coverage for server module; small adjustments

This commit is contained in:
Daniil Fajnberg 2022-02-13 16:17:50 +01:00
parent be03097bf4
commit 3fb451a00e
4 changed files with 203 additions and 12 deletions

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@ -1,6 +1,6 @@
[metadata]
name = asyncio-taskpool
version = 0.3.0
version = 0.3.1
author = Daniil Fajnberg
author_email = mail@daniil.fajnberg.de
description = Dynamically manage pools of asyncio tasks

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@ -31,74 +31,121 @@ from typing import Optional, Union
from .client import ControlClient, UnixControlClient
from .pool import TaskPool, SimpleTaskPool
from .session import ControlSession
from .types import ConnectedCallbackT
log = logging.getLogger(__name__)
class ControlServer(ABC): # TODO: Implement interface for normal TaskPool instances, not just SimpleTaskPool
"""
Abstract base class for a task pool control server.
This class acts as a wrapper around an async server instance and initializes a `ControlSession` upon a client
connecting to it. The entire interface is defined within that session class.
"""
_client_class = ControlClient
@classmethod
@property
def client_class_name(cls) -> str:
"""Returns the name of the control client class matching the server class."""
return cls._client_class.__name__
@abstractmethod
async def get_server_instance(self, client_connected_cb, **kwargs) -> AbstractServer:
async def _get_server_instance(self, client_connected_cb: ConnectedCallbackT, **kwargs) -> AbstractServer:
"""
Initializes, starts, and returns an async server instance (Unix or TCP type).
Args:
client_connected_cb:
The callback for when a client connects to the server (as per `asyncio.start_server` or
`asyncio.start_unix_server`); will always be the internal `_client_connected_cb` method.
**kwargs (optional):
Keyword arguments to pass into the function that starts the server.
Returns:
The running server object (a type of `asyncio.Server`).
"""
raise NotImplementedError
@abstractmethod
def final_callback(self) -> None:
def _final_callback(self) -> None:
"""The method to run after the server's `serve_forever` methods ends for whatever reason."""
raise NotImplementedError
def __init__(self, pool: Union[TaskPool, SimpleTaskPool], **server_kwargs) -> None:
"""
Initializes by merely saving the internal attributes, but without starting the server yet.
The task pool must be passed here and can not be set/changed afterwards. This means a control server is always
tied to one specific task pool.
Args:
pool:
An instance of a `BaseTaskPool` subclass to tie the server to.
**server_kwargs (optional):
Keyword arguments that will be passed into the function that starts the server.
"""
self._pool: Union[TaskPool, SimpleTaskPool] = pool
self._server_kwargs = server_kwargs
self._server: Optional[AbstractServer] = None
def __str__(self) -> str:
return f"{self.__class__.__name__} for {self._pool}"
@property
def pool(self) -> Union[TaskPool, SimpleTaskPool]:
"""Read-only property for accessing the task pool instance controlled by the server."""
return self._pool
def is_serving(self) -> bool:
"""Wrapper around the `asyncio.Server.is_serving` method."""
return self._server.is_serving()
async def _client_connected_cb(self, reader: StreamReader, writer: StreamWriter) -> None:
"""
The universal client callback that will be passed into the `_get_server_instance` method.
Instantiates a control session, performs the client handshake, and enters the session's `listen` loop.
"""
session = ControlSession(self, reader, writer)
await session.client_handshake()
await session.listen()
async def _serve_forever(self) -> None:
"""
To be run as an `asyncio.Task` by the following method.
Serves as a wrapper around the the `asyncio.Server.serve_forever` method that ensures that the `_final_callback`
method is called, when the former method ends for whatever reason.
"""
try:
async with self._server:
await self._server.serve_forever()
except CancelledError:
log.debug("%s stopped", self.__class__.__name__)
finally:
self.final_callback()
self._final_callback()
async def serve_forever(self) -> Task:
"""
This method actually starts the server and begins listening to client connections on the specified interface.
It should never block because the serving will be performed in a separate task.
"""
log.debug("Starting %s...", self.__class__.__name__)
self._server = await self.get_server_instance(self._client_connected_cb, **self._server_kwargs)
self._server = await self._get_server_instance(self._client_connected_cb, **self._server_kwargs)
return create_task(self._serve_forever())
class UnixControlServer(ControlServer):
"""Task pool control server class that exposes a unix socket for control clients to connect to."""
_client_class = UnixControlClient
def __init__(self, pool: SimpleTaskPool, **server_kwargs) -> None:
self._socket_path = Path(server_kwargs.pop('path'))
super().__init__(pool, **server_kwargs)
async def get_server_instance(self, client_connected_cb, **kwargs) -> AbstractServer:
srv = await start_unix_server(client_connected_cb, self._socket_path, **kwargs)
async def _get_server_instance(self, client_connected_cb: ConnectedCallbackT, **kwargs) -> AbstractServer:
server = await start_unix_server(client_connected_cb, self._socket_path, **kwargs)
log.debug("Opened socket '%s'", str(self._socket_path))
return srv
return server
def final_callback(self) -> None:
def _final_callback(self) -> None:
"""Removes the unix socket on which the server was listening."""
self._socket_path.unlink()
log.debug("Removed socket '%s'", str(self._socket_path))

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@ -34,4 +34,5 @@ CoroutineFunc = Callable[[...], Awaitable[Any]]
EndCallbackT = Callable
CancelCallbackT = Callable
ConnectedCallbackT = Callable[[StreamReader, StreamWriter], Awaitable[None]]
ClientConnT = Union[Tuple[StreamReader, StreamWriter], Tuple[None, None]]

143
tests/test_server.py Normal file
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@ -0,0 +1,143 @@
import asyncio
import logging
from pathlib import Path
from unittest import IsolatedAsyncioTestCase
from unittest.mock import AsyncMock, MagicMock, patch
from asyncio_taskpool import server
from asyncio_taskpool.client import ControlClient, UnixControlClient
FOO, BAR = 'foo', 'bar'
class ControlServerTestCase(IsolatedAsyncioTestCase):
log_lvl: int
@classmethod
def setUpClass(cls) -> None:
cls.log_lvl = server.log.level
server.log.setLevel(999)
@classmethod
def tearDownClass(cls) -> None:
server.log.setLevel(cls.log_lvl)
def setUp(self) -> None:
self.abstract_patcher = patch('asyncio_taskpool.server.ControlServer.__abstractmethods__', set())
self.mock_abstract_methods = self.abstract_patcher.start()
self.mock_pool = MagicMock()
self.kwargs = {FOO: 123, BAR: 456}
self.server = server.ControlServer(pool=self.mock_pool, **self.kwargs)
def tearDown(self) -> None:
self.abstract_patcher.stop()
def test_client_class_name(self):
self.assertEqual(ControlClient.__name__, server.ControlServer.client_class_name)
async def test_abstract(self):
with self.assertRaises(NotImplementedError):
args = [AsyncMock()]
await self.server._get_server_instance(*args)
with self.assertRaises(NotImplementedError):
self.server._final_callback()
def test_init(self):
self.assertEqual(self.mock_pool, self.server._pool)
self.assertEqual(self.kwargs, self.server._server_kwargs)
self.assertIsNone(self.server._server)
def test_pool(self):
self.assertEqual(self.mock_pool, self.server.pool)
def test_is_serving(self):
self.server._server = MagicMock(is_serving=MagicMock(return_value=FOO + BAR))
self.assertEqual(FOO + BAR, self.server.is_serving())
@patch.object(server, 'ControlSession')
async def test__client_connected_cb(self, mock_client_session_cls: MagicMock):
mock_client_handshake, mock_listen = AsyncMock(), AsyncMock()
mock_client_session_cls.return_value = MagicMock(client_handshake=mock_client_handshake, listen=mock_listen)
mock_reader, mock_writer = MagicMock(), MagicMock()
self.assertIsNone(await self.server._client_connected_cb(mock_reader, mock_writer))
mock_client_session_cls.assert_called_once_with(self.server, mock_reader, mock_writer)
mock_client_handshake.assert_awaited_once_with()
mock_listen.assert_awaited_once_with()
@patch.object(server.ControlServer, '_final_callback')
async def test__serve_forever(self, mock__final_callback: MagicMock):
mock_aenter, mock_serve_forever = AsyncMock(), AsyncMock(side_effect=asyncio.CancelledError)
self.server._server = MagicMock(__aenter__=mock_aenter, serve_forever=mock_serve_forever)
with self.assertLogs(server.log, logging.DEBUG):
self.assertIsNone(await self.server._serve_forever())
mock_aenter.assert_awaited_once_with()
mock_serve_forever.assert_awaited_once_with()
mock__final_callback.assert_called_once_with()
mock_aenter.reset_mock()
mock_serve_forever.reset_mock(side_effect=True)
mock__final_callback.reset_mock()
self.assertIsNone(await self.server._serve_forever())
mock_aenter.assert_awaited_once_with()
mock_serve_forever.assert_awaited_once_with()
mock__final_callback.assert_called_once_with()
@patch.object(server, 'create_task')
@patch.object(server.ControlServer, '_serve_forever', new_callable=MagicMock())
@patch.object(server.ControlServer, '_get_server_instance')
async def test_serve_forever(self, mock__get_server_instance: AsyncMock, mock__serve_forever: MagicMock,
mock_create_task: MagicMock):
mock__serve_forever.return_value = mock_awaitable = 'some_coroutine'
mock_create_task.return_value = expected_output = 12345
output = await self.server.serve_forever()
self.assertEqual(expected_output, output)
mock__get_server_instance.assert_awaited_once_with(self.server._client_connected_cb, **self.kwargs)
mock__serve_forever.assert_called_once_with()
mock_create_task.assert_called_once_with(mock_awaitable)
class UnixControlServerTestCase(IsolatedAsyncioTestCase):
log_lvl: int
@classmethod
def setUpClass(cls) -> None:
cls.log_lvl = server.log.level
server.log.setLevel(999)
@classmethod
def tearDownClass(cls) -> None:
server.log.setLevel(cls.log_lvl)
def setUp(self) -> None:
self.base_init_patcher = patch.object(server.ControlServer, '__init__')
self.mock_base_init = self.base_init_patcher.start()
self.mock_pool = MagicMock()
self.path = '/tmp/asyncio_taskpool'
self.kwargs = {FOO: 123, BAR: 456}
self.server = server.UnixControlServer(pool=self.mock_pool, path=self.path, **self.kwargs)
def tearDown(self) -> None:
self.base_init_patcher.stop()
def test__client_class(self):
self.assertEqual(UnixControlClient, self.server._client_class)
def test_init(self):
self.assertEqual(Path(self.path), self.server._socket_path)
self.mock_base_init.assert_called_once_with(self.mock_pool, **self.kwargs)
@patch.object(server, 'start_unix_server')
async def test__get_server_instance(self, mock_start_unix_server: AsyncMock):
mock_start_unix_server.return_value = expected_output = 'totally_a_server'
mock_callback, mock_kwargs = MagicMock(), {'a': 1, 'b': 2}
args = [mock_callback]
output = await self.server._get_server_instance(*args, **mock_kwargs)
self.assertEqual(expected_output, output)
mock_start_unix_server.assert_called_once_with(mock_callback, Path(self.path), **mock_kwargs)
def test__final_callback(self):
self.server._socket_path = MagicMock()
self.assertIsNone(self.server._final_callback())
self.server._socket_path.unlink.assert_called_once_with()