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felixdivofelixdivo
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Add more typying (hardbyte#1012)
* simplify test_socketcan.py * type base classes * type ctypesutil.py; the last file in can/*.py not being typed
1 parent a116c8a commit 941d2aa

5 files changed

Lines changed: 106 additions & 113 deletions

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‎.travis.yml‎

Lines changed: 1 addition & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -89,22 +89,7 @@ jobs:
8989
--python-version=3.7
9090
--ignore-missing-imports
9191
--no-implicit-optional
92-
can/bit_timing.py
93-
can/broadcastmanager.py
94-
can/bus.py
95-
can/interface.py
96-
can/interfaces/udp_multicast/**.py
97-
can/interfaces/slcan.py
98-
can/interfaces/socketcan/**.py
99-
can/interfaces/virtual.py
100-
can/listener.py
101-
can/logger.py
102-
can/message.py
103-
can/notifier.py
104-
can/player.py
105-
can/thread_safe_bus.py
106-
can/typechecking.py
107-
can/util.py
92+
can/*.py
10893
can/io/**.py
10994
scripts/**.py
11095
examples/**.py

‎can/broadcastmanager.py‎

Lines changed: 19 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -36,7 +36,7 @@ class CyclicTask:
3636
"""
3737

3838
@abc.abstractmethod
39-
def stop(self):
39+
def stop(self) -> None:
4040
"""Cancel this periodic task.
4141
4242
:raises can.CanError:
@@ -49,7 +49,9 @@ class CyclicSendTaskABC(CyclicTask):
4949
Message send task with defined period
5050
"""
5151

52-
def __init__(self, messages: Union[Sequence[Message], Message], period: float):
52+
def __init__(
53+
self, messages: Union[Sequence[Message], Message], period: float
54+
) -> None:
5355
"""
5456
:param messages:
5557
The messages to be sent periodically.
@@ -104,7 +106,7 @@ def __init__(
104106
messages: Union[Sequence[Message], Message],
105107
period: float,
106108
duration: Optional[float],
107-
):
109+
) -> None:
108110
"""Message send task with a defined duration and period.
109111
110112
:param messages:
@@ -122,14 +124,14 @@ class RestartableCyclicTaskABC(CyclicSendTaskABC):
122124
"""Adds support for restarting a stopped cyclic task"""
123125

124126
@abc.abstractmethod
125-
def start(self):
127+
def start(self) -> None:
126128
"""Restart a stopped periodic task."""
127129

128130

129131
class ModifiableCyclicTaskABC(CyclicSendTaskABC):
130132
"""Adds support for modifying a periodic message"""
131133

132-
def _check_modified_messages(self, messages: Tuple[Message, ...]):
134+
def _check_modified_messages(self, messages: Tuple[Message, ...]) -> None:
133135
"""Helper function to perform error checking when modifying the data in
134136
the cyclic task.
135137
@@ -149,7 +151,7 @@ def _check_modified_messages(self, messages: Tuple[Message, ...]):
149151
"from when the task was created"
150152
)
151153

152-
def modify_data(self, messages: Union[Sequence[Message], Message]):
154+
def modify_data(self, messages: Union[Sequence[Message], Message]) -> None:
153155
"""Update the contents of the periodically sent messages, without
154156
altering the timing.
155157
@@ -178,7 +180,7 @@ def __init__(
178180
count: int,
179181
initial_period: float,
180182
subsequent_period: float,
181-
):
183+
) -> None:
182184
"""
183185
Transmits a message `count` times at `initial_period` then continues to
184186
transmit messages at `subsequent_period`.
@@ -206,12 +208,12 @@ def __init__(
206208
period: float,
207209
duration: Optional[float] = None,
208210
on_error: Optional[Callable[[Exception], bool]] = None,
209-
):
211+
) -> None:
210212
"""Transmits `messages` with a `period` seconds for `duration` seconds on a `bus`.
211213
212214
The `on_error` is called if any error happens on `bus` while sending `messages`.
213215
If `on_error` present, and returns ``False`` when invoked, thread is
214-
stopped immediately, otherwise, thread continuiously tries to send `messages`
216+
stopped immediately, otherwise, thread continuously tries to send `messages`
215217
ignoring errors on a `bus`. Absence of `on_error` means that thread exits immediately
216218
on error.
217219
@@ -224,22 +226,24 @@ def __init__(
224226
self.bus = bus
225227
self.send_lock = lock
226228
self.stopped = True
227-
self.thread = None
228-
self.end_time = time.perf_counter() + duration if duration else None
229+
self.thread: Optional[threading.Thread] = None
230+
self.end_time: Optional[float] = (
231+
time.perf_counter() + duration if duration else None
232+
)
229233
self.on_error = on_error
230234

231235
if HAS_EVENTS:
232-
self.period_ms: int = int(round(period * 1000, 0))
236+
self.period_ms = int(round(period * 1000, 0))
233237
self.event = win32event.CreateWaitableTimer(None, False, None)
234238

235239
self.start()
236240

237-
def stop(self):
241+
def stop(self) -> None:
238242
if HAS_EVENTS:
239243
win32event.CancelWaitableTimer(self.event.handle)
240244
self.stopped = True
241245

242-
def start(self):
246+
def start(self) -> None:
243247
self.stopped = False
244248
if self.thread is None or not self.thread.is_alive():
245249
name = "Cyclic send task for 0x%X" % (self.messages[0].arbitration_id)
@@ -253,7 +257,7 @@ def start(self):
253257

254258
self.thread.start()
255259

256-
def _run(self):
260+
def _run(self) -> None:
257261
msg_index = 0
258262
while not self.stopped:
259263
# Prevent calling bus.send from multiple threads

‎can/bus.py‎

Lines changed: 36 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -6,14 +6,14 @@
66

77
import can.typechecking
88

9-
from abc import ABCMeta, abstractmethod
9+
from abc import ABC, ABCMeta, abstractmethod
1010
import can
1111
import logging
1212
import threading
1313
from time import time
1414
from enum import Enum, auto
1515

16-
from can.broadcastmanager import ThreadBasedCyclicSendTask
16+
from can.broadcastmanager import ThreadBasedCyclicSendTask, CyclicSendTaskABC
1717
from can.message import Message
1818

1919
LOG = logging.getLogger(__name__)
@@ -61,7 +61,7 @@ def __init__(
6161
:param dict kwargs:
6262
Any backend dependent configurations are passed in this dictionary
6363
"""
64-
self._periodic_tasks: List[can.broadcastmanager.CyclicSendTaskABC] = []
64+
self._periodic_tasks: List[_SelfRemovingCyclicTask] = []
6565
self.set_filters(can_filters)
6666

6767
def __str__(self) -> str:
@@ -172,7 +172,7 @@ def send(self, msg: Message, timeout: Optional[float] = None) -> None:
172172

173173
def send_periodic(
174174
self,
175-
msgs: Union[Sequence[Message], Message],
175+
msgs: Union[Message, Sequence[Message]],
176176
period: float,
177177
duration: Optional[float] = None,
178178
store_task: bool = True,
@@ -188,7 +188,7 @@ def send_periodic(
188188
- the task's :meth:`CyclicTask.stop()` method is called.
189189
190190
:param msgs:
191-
Messages to transmit
191+
Message(s) to transmit
192192
:param period:
193193
Period in seconds between each message
194194
:param duration:
@@ -215,26 +215,35 @@ def send_periodic(
215215
appropriate as the stopped tasks are still taking up memory as they
216216
are associated with the Bus instance.
217217
"""
218-
if not isinstance(msgs, (list, tuple)):
219-
if isinstance(msgs, Message):
220-
msgs = [msgs]
221-
else:
222-
raise ValueError("Must be either a list, tuple, or a Message")
223-
if not msgs:
224-
raise ValueError("Must be at least a list or tuple of length 1")
225-
task = self._send_periodic_internal(msgs, period, duration)
218+
if isinstance(msgs, Message):
219+
msgs = [msgs]
220+
elif isinstance(msgs, Sequence):
221+
# A Sequence does not necessarily provide __bool__ we need to use len()
222+
if len(msgs) == 0:
223+
raise ValueError("Must be a sequence at least of length 1")
224+
else:
225+
raise ValueError("Must be either a message or a sequence of messages")
226+
227+
# Create a backend specific task; will be patched to a _SelfRemovingCyclicTask later
228+
task = cast(
229+
_SelfRemovingCyclicTask,
230+
self._send_periodic_internal(msgs, period, duration),
231+
)
232+
226233
# we wrap the task's stop method to also remove it from the Bus's list of tasks
234+
periodic_tasks = self._periodic_tasks
227235
original_stop_method = task.stop
228236

229-
def wrapped_stop_method(remove_task=True):
237+
def wrapped_stop_method(remove_task: bool = True) -> None:
238+
nonlocal task, periodic_tasks, original_stop_method
230239
if remove_task:
231240
try:
232-
self._periodic_tasks.remove(task)
241+
periodic_tasks.remove(task)
233242
except ValueError:
234-
pass
243+
pass # allow the task to be already removed
235244
original_stop_method()
236245

237-
setattr(task, "stop", wrapped_stop_method)
246+
task.stop = wrapped_stop_method # type: ignore
238247

239248
if store_task:
240249
self._periodic_tasks.append(task)
@@ -273,13 +282,13 @@ def _send_periodic_internal(
273282
)
274283
return task
275284

276-
def stop_all_periodic_tasks(self, remove_tasks=True):
285+
def stop_all_periodic_tasks(self, remove_tasks: bool = True) -> None:
277286
"""Stop sending any messages that were started using **bus.send_periodic**.
278287
279288
.. note::
280289
The result is undefined if a single task throws an exception while being stopped.
281290
282-
:param bool remove_tasks:
291+
:param remove_tasks:
283292
Stop tracking the stopped tasks.
284293
"""
285294
for task in self._periodic_tasks:
@@ -288,7 +297,7 @@ def stop_all_periodic_tasks(self, remove_tasks=True):
288297
task.stop(remove_task=False)
289298

290299
if remove_tasks:
291-
self._periodic_tasks = []
300+
self._periodic_tasks.clear()
292301

293302
def __iter__(self) -> Iterator[Message]:
294303
"""Allow iteration on messages as they are received.
@@ -434,3 +443,10 @@ def _detect_available_configs() -> List[can.typechecking.AutoDetectedConfig]:
434443

435444
def fileno(self) -> int:
436445
raise NotImplementedError("fileno is not implemented using current CAN bus")
446+
447+
448+
class _SelfRemovingCyclicTask(CyclicSendTaskABC, ABC):
449+
"""Removes itself from a bus. Only needed for typing :meth:`Bus._periodic_tasks`. Do not instantiate."""
450+
451+
def stop(self, remove_task: bool = True) -> None:
452+
raise NotImplementedError()

‎can/ctypesutil.py‎

Lines changed: 34 additions & 48 deletions
Original file line numberDiff line numberDiff line change
@@ -6,23 +6,40 @@
66
import logging
77
import sys
88

9+
from typing import Any, Callable, Optional, Tuple, Union
10+
911
log = logging.getLogger("can.ctypesutil")
1012

1113
__all__ = ["CLibrary", "HANDLE", "PHANDLE", "HRESULT"]
1214

15+
1316
try:
14-
_LibBase = ctypes.WinDLL
17+
_LibBase = ctypes.WinDLL # type: ignore
18+
_FUNCTION_TYPE = ctypes.WINFUNCTYPE # type: ignore
1519
except AttributeError:
1620
_LibBase = ctypes.CDLL
21+
_FUNCTION_TYPE = ctypes.CFUNCTYPE
1722

1823

19-
class LibraryMixin:
20-
def map_symbol(self, func_name, restype=None, argtypes=(), errcheck=None):
24+
class CLibrary(_LibBase): # type: ignore
25+
def __init__(self, library_or_path: Union[str, ctypes.CDLL]) -> None:
26+
if isinstance(library_or_path, str):
27+
super().__init__(library_or_path)
28+
else:
29+
super().__init__(library_or_path._name, library_or_path._handle)
30+
31+
def map_symbol(
32+
self,
33+
func_name: str,
34+
restype: Any = None,
35+
argtypes: Tuple[Any, ...] = (),
36+
errcheck: Optional[Callable[..., Any]] = None,
37+
) -> Any:
2138
"""
2239
Map and return a symbol (function) from a C library. A reference to the
2340
mapped symbol is also held in the instance
2441
25-
:param str func_name:
42+
:param func_name:
2643
symbol_name
2744
:param ctypes.c_* restype:
2845
function result type (i.e. ctypes.c_ulong...), defaults to void
@@ -32,67 +49,36 @@ def map_symbol(self, func_name, restype=None, argtypes=(), errcheck=None):
3249
optional error checking function, see ctypes docs for _FuncPtr
3350
"""
3451
if argtypes:
35-
prototype = self.function_type(restype, *argtypes)
52+
prototype = _FUNCTION_TYPE(restype, *argtypes)
3653
else:
37-
prototype = self.function_type(restype)
54+
prototype = _FUNCTION_TYPE(restype)
3855
try:
39-
symbol = prototype((func_name, self))
56+
symbol: Any = prototype((func_name, self))
4057
except AttributeError:
4158
raise ImportError(
42-
"Could not map function '{}' from library {}".format(
43-
func_name, self._name
44-
)
59+
f'Could not map function "{func_name}" from library {self._name}'
4560
) from None
4661

47-
setattr(symbol, "_name", func_name)
62+
symbol._name = func_name
4863
log.debug(
4964
f'Wrapped function "{func_name}", result type: {type(restype)}, error_check {errcheck}'
5065
)
5166

52-
if errcheck:
67+
if errcheck is not None:
5368
symbol.errcheck = errcheck
5469

55-
setattr(self, func_name, symbol)
56-
return symbol
57-
58-
59-
class CLibrary_Win32(_LibBase, LibraryMixin):
60-
" Basic ctypes.WinDLL derived class + LibraryMixin "
61-
62-
def __init__(self, library_or_path):
63-
if isinstance(library_or_path, str):
64-
super().__init__(library_or_path)
65-
else:
66-
super().__init__(library_or_path._name, library_or_path._handle)
67-
68-
@property
69-
def function_type(self):
70-
return ctypes.WINFUNCTYPE
71-
70+
self.func_name = symbol
7271

73-
class CLibrary_Unix(ctypes.CDLL, LibraryMixin):
74-
" Basic ctypes.CDLL derived class + LibraryMixin "
75-
76-
def __init__(self, library_or_path):
77-
if isinstance(library_or_path, str):
78-
super().__init__(library_or_path)
79-
else:
80-
super().__init__(library_or_path._name, library_or_path._handle)
81-
82-
@property
83-
def function_type(self):
84-
return ctypes.CFUNCTYPE
72+
return symbol
8573

8674

8775
if sys.platform == "win32":
88-
CLibrary = CLibrary_Win32
8976
HRESULT = ctypes.HRESULT
90-
else:
91-
CLibrary = CLibrary_Unix
92-
if sys.platform == "cygwin":
93-
# Define HRESULT for cygwin
94-
class HRESULT(ctypes.c_long):
95-
pass
77+
78+
elif sys.platform == "cygwin":
79+
80+
class HRESULT(ctypes.c_long):
81+
pass
9682

9783

9884
# Common win32 definitions

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