1# Copyright 2016 Étienne Bersac
2# Copyright 2016 Julien Danjou
3# Copyright 2016 Joshua Harlow
4# Copyright 2013-2014 Ray Holder
5#
6# Licensed under the Apache License, Version 2.0 (the "License");
7# you may not use this file except in compliance with the License.
8# You may obtain a copy of the License at
9#
10# http://www.apache.org/licenses/LICENSE-2.0
11#
12# Unless required by applicable law or agreed to in writing, software
13# distributed under the License is distributed on an "AS IS" BASIS,
14# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15# See the License for the specific language governing permissions and
16# limitations under the License.
17
18import functools
19import sys
20import typing as t
21
22import tenacity
23from tenacity import AttemptManager
24from tenacity import BaseRetrying
25from tenacity import DoAttempt
26from tenacity import DoSleep
27from tenacity import RetryCallState
28from tenacity import RetryError
29from tenacity import after_nothing
30from tenacity import before_nothing
31from tenacity import _utils
32
33# Import all built-in retry strategies for easier usage.
34from .retry import RetryBaseT
35from .retry import retry_all # noqa
36from .retry import retry_any # noqa
37from .retry import retry_if_exception # noqa
38from .retry import retry_if_result # noqa
39from ..retry import RetryBaseT as SyncRetryBaseT
40
41if t.TYPE_CHECKING:
42 from tenacity.stop import StopBaseT
43 from tenacity.wait import WaitBaseT
44
45WrappedFnReturnT = t.TypeVar("WrappedFnReturnT")
46WrappedFn = t.TypeVar("WrappedFn", bound=t.Callable[..., t.Awaitable[t.Any]])
47
48
49def _portable_async_sleep(seconds: float) -> t.Awaitable[None]:
50 # If trio is already imported, then importing it is cheap.
51 # If trio isn't already imported, then it's definitely not running, so we
52 # can skip further checks.
53 if "trio" in sys.modules:
54 # If trio is available, then sniffio is too
55 import trio
56 import sniffio
57
58 if sniffio.current_async_library() == "trio":
59 return trio.sleep(seconds)
60 # Otherwise, assume asyncio
61 # Lazy import asyncio as it's expensive (responsible for 25-50% of total import overhead).
62 import asyncio
63
64 return asyncio.sleep(seconds)
65
66
67class AsyncRetrying(BaseRetrying):
68 def __init__(
69 self,
70 sleep: t.Callable[
71 [t.Union[int, float]], t.Union[None, t.Awaitable[None]]
72 ] = _portable_async_sleep,
73 stop: "StopBaseT" = tenacity.stop.stop_never,
74 wait: "WaitBaseT" = tenacity.wait.wait_none(),
75 retry: "t.Union[SyncRetryBaseT, RetryBaseT]" = tenacity.retry_if_exception_type(),
76 before: t.Callable[
77 ["RetryCallState"], t.Union[None, t.Awaitable[None]]
78 ] = before_nothing,
79 after: t.Callable[
80 ["RetryCallState"], t.Union[None, t.Awaitable[None]]
81 ] = after_nothing,
82 before_sleep: t.Optional[
83 t.Callable[["RetryCallState"], t.Union[None, t.Awaitable[None]]]
84 ] = None,
85 reraise: bool = False,
86 retry_error_cls: t.Type["RetryError"] = RetryError,
87 retry_error_callback: t.Optional[
88 t.Callable[["RetryCallState"], t.Union[t.Any, t.Awaitable[t.Any]]]
89 ] = None,
90 ) -> None:
91 super().__init__(
92 sleep=sleep, # type: ignore[arg-type]
93 stop=stop,
94 wait=wait,
95 retry=retry, # type: ignore[arg-type]
96 before=before, # type: ignore[arg-type]
97 after=after, # type: ignore[arg-type]
98 before_sleep=before_sleep, # type: ignore[arg-type]
99 reraise=reraise,
100 retry_error_cls=retry_error_cls,
101 retry_error_callback=retry_error_callback,
102 )
103
104 async def __call__( # type: ignore[override]
105 self, fn: WrappedFn, *args: t.Any, **kwargs: t.Any
106 ) -> WrappedFnReturnT:
107 self.begin()
108
109 retry_state = RetryCallState(retry_object=self, fn=fn, args=args, kwargs=kwargs)
110 while True:
111 do = await self.iter(retry_state=retry_state)
112 if isinstance(do, DoAttempt):
113 try:
114 result = await fn(*args, **kwargs)
115 except BaseException: # noqa: B902
116 retry_state.set_exception(sys.exc_info()) # type: ignore[arg-type]
117 else:
118 retry_state.set_result(result)
119 elif isinstance(do, DoSleep):
120 retry_state.prepare_for_next_attempt()
121 await self.sleep(do) # type: ignore[misc]
122 else:
123 return do # type: ignore[no-any-return]
124
125 def _add_action_func(self, fn: t.Callable[..., t.Any]) -> None:
126 self.iter_state.actions.append(_utils.wrap_to_async_func(fn))
127
128 async def _run_retry(self, retry_state: "RetryCallState") -> None: # type: ignore[override]
129 self.iter_state.retry_run_result = await _utils.wrap_to_async_func(self.retry)(
130 retry_state
131 )
132
133 async def _run_wait(self, retry_state: "RetryCallState") -> None: # type: ignore[override]
134 if self.wait:
135 sleep = await _utils.wrap_to_async_func(self.wait)(retry_state)
136 else:
137 sleep = 0.0
138
139 retry_state.upcoming_sleep = sleep
140
141 async def _run_stop(self, retry_state: "RetryCallState") -> None: # type: ignore[override]
142 self.statistics["delay_since_first_attempt"] = retry_state.seconds_since_start
143 self.iter_state.stop_run_result = await _utils.wrap_to_async_func(self.stop)(
144 retry_state
145 )
146
147 async def iter(
148 self, retry_state: "RetryCallState"
149 ) -> t.Union[DoAttempt, DoSleep, t.Any]: # noqa: A003
150 self._begin_iter(retry_state)
151 result = None
152 for action in self.iter_state.actions:
153 result = await action(retry_state)
154 return result
155
156 def __iter__(self) -> t.Generator[AttemptManager, None, None]:
157 raise TypeError("AsyncRetrying object is not iterable")
158
159 def __aiter__(self) -> "AsyncRetrying":
160 self.begin()
161 self._retry_state = RetryCallState(self, fn=None, args=(), kwargs={})
162 return self
163
164 async def __anext__(self) -> AttemptManager:
165 while True:
166 do = await self.iter(retry_state=self._retry_state)
167 if do is None:
168 raise StopAsyncIteration
169 elif isinstance(do, DoAttempt):
170 return AttemptManager(retry_state=self._retry_state)
171 elif isinstance(do, DoSleep):
172 self._retry_state.prepare_for_next_attempt()
173 await self.sleep(do) # type: ignore[misc]
174 else:
175 raise StopAsyncIteration
176
177 def wraps(self, fn: WrappedFn) -> WrappedFn:
178 wrapped = super().wraps(fn)
179 # Ensure wrapper is recognized as a coroutine function.
180
181 @functools.wraps(
182 fn, functools.WRAPPER_ASSIGNMENTS + ("__defaults__", "__kwdefaults__")
183 )
184 async def async_wrapped(*args: t.Any, **kwargs: t.Any) -> t.Any:
185 # Always create a copy to prevent overwriting the local contexts when
186 # calling the same wrapped functions multiple times in the same stack
187 copy = self.copy()
188 async_wrapped.statistics = copy.statistics # type: ignore[attr-defined]
189 return await copy(fn, *args, **kwargs)
190
191 # Preserve attributes
192 async_wrapped.retry = self # type: ignore[attr-defined]
193 async_wrapped.retry_with = wrapped.retry_with # type: ignore[attr-defined]
194 async_wrapped.statistics = {} # type: ignore[attr-defined]
195
196 return async_wrapped # type: ignore[return-value]
197
198
199__all__ = [
200 "retry_all",
201 "retry_any",
202 "retry_if_exception",
203 "retry_if_result",
204 "WrappedFn",
205 "AsyncRetrying",
206]