import asyncio import logging import sys from abc import abstractmethod from dataclasses import dataclass from types import TracebackType from typing import ( Any, Awaitable, Callable, Dict, Generator, List, Optional, Tuple, Type, Union, ) from aiohttp import ClientResponse, ClientSession, hdrs from aiohttp.typedefs import StrOrURL from yarl import URL as YARL_URL from .retry_options import ExponentialRetry, RetryOptionsBase if sys.version_info >= (3, 8): from typing import Protocol else: from typing_extensions import Protocol class _Logger(Protocol): """ _Logger defines which methods logger object should have """ @abstractmethod def debug(self, msg: str, *args: Any, **kwargs: Any) -> None: pass @abstractmethod def warning(self, msg: str, *args: Any, **kwargs: Any) -> None: pass @abstractmethod def exception(self, msg: str, *args: Any, **kwargs: Any) -> None: pass # url itself or list of urls for changing between retries _RAW_URL_TYPE = Union[StrOrURL, YARL_URL] _URL_TYPE = Union[_RAW_URL_TYPE, List[_RAW_URL_TYPE], Tuple[_RAW_URL_TYPE, ...]] _LoggerType = Union[_Logger, logging.Logger] RequestFunc = Callable[..., Awaitable[ClientResponse]] @dataclass class RequestParams: method: str url: _RAW_URL_TYPE headers: Optional[Dict[str, Any]] = None trace_request_ctx: Optional[Dict[str, Any]] = None kwargs: Optional[Dict[str, Any]] = None class _RequestContext: def __init__( self, request_func: RequestFunc, params_list: List[RequestParams], logger: _LoggerType, retry_options: RetryOptionsBase, raise_for_status: bool = False, ) -> None: assert len(params_list) > 0 self._request_func = request_func self._params_list = params_list self._logger = logger self._retry_options = retry_options self._raise_for_status = raise_for_status self._response: Optional[ClientResponse] = None def _is_status_code_ok(self, code: int) -> bool: if code >= 500 and self._retry_options.retry_all_server_errors: return False return code not in self._retry_options.statuses async def _do_request(self) -> ClientResponse: current_attempt = 0 while True: self._logger.debug(f"Attempt {current_attempt+1} out of {self._retry_options.attempts}") current_attempt += 1 try: try: params = self._params_list[current_attempt - 1] except IndexError: params = self._params_list[-1] response: ClientResponse = await self._request_func( params.method, params.url, headers=params.headers, trace_request_ctx={ 'current_attempt': current_attempt, **(params.trace_request_ctx or {}), }, **(params.kwargs or {}), ) if self._is_status_code_ok(response.status) or current_attempt == self._retry_options.attempts: if self._raise_for_status: response.raise_for_status() if self._retry_options.evaluate_response_callback is not None: try: is_response_correct = await self._retry_options.evaluate_response_callback(response) except Exception: self._logger.exception('while evaluating response an exception occurred') is_response_correct = False else: is_response_correct = True if is_response_correct or current_attempt == self._retry_options.attempts: self._response = response return response else: self._logger.debug(f"Retrying after evaluate response callback check") else: self._logger.debug(f"Retrying after response code: {response.status}") retry_wait = self._retry_options.get_timeout(attempt=current_attempt, response=response) except Exception as e: if current_attempt >= self._retry_options.attempts: raise e is_exc_valid = any([isinstance(e, exc) for exc in self._retry_options.exceptions]) if not is_exc_valid: raise e self._logger.debug(f"Retrying after exception: {repr(e)}") retry_wait = self._retry_options.get_timeout(attempt=current_attempt, response=None) await asyncio.sleep(retry_wait) def __await__(self) -> Generator[Any, None, ClientResponse]: return self.__aenter__().__await__() async def __aenter__(self) -> ClientResponse: return await self._do_request() async def __aexit__( self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType], ) -> None: if self._response is not None: if not self._response.closed: self._response.close() def _url_to_urls(url: _URL_TYPE) -> Tuple[StrOrURL, ...]: if isinstance(url, str) or isinstance(url, YARL_URL): return (url,) if isinstance(url, list): urls = tuple(url) elif isinstance(url, tuple): urls = url else: raise ValueError("you can pass url only by str or list/tuple") if len(urls) == 0: raise ValueError("you can pass url by str or list/tuple with attempts count size") return urls class RetryClient: def __init__( self, client_session: Optional[ClientSession] = None, logger: Optional[_LoggerType] = None, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: bool = False, *args: Any, **kwargs: Any, ) -> None: if client_session is not None: client = client_session closed = None else: client = ClientSession(*args, **kwargs) closed = False self._client = client self._closed = closed self._logger: _LoggerType = logger or logging.getLogger("aiohttp_retry") self._retry_options: RetryOptionsBase = retry_options or ExponentialRetry() self._raise_for_status = raise_for_status @property def retry_options(self) -> RetryOptionsBase: return self._retry_options def requests( self, params_list: List[RequestParams], retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, ) -> _RequestContext: return self._make_requests( params_list=params_list, retry_options=retry_options, raise_for_status=raise_for_status, ) def request( self, method: str, url: StrOrURL, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=method, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def get( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_GET, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def options( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_OPTIONS, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def head( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_HEAD, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def post( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_POST, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def put( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_PUT, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def patch( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_PATCH, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) def delete( self, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: return self._make_request( method=hdrs.METH_DELETE, url=url, retry_options=retry_options, raise_for_status=raise_for_status, **kwargs, ) async def close(self) -> None: await self._client.close() self._closed = True def _make_request( self, method: str, url: _URL_TYPE, retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, **kwargs: Any, ) -> _RequestContext: url_list = _url_to_urls(url) params_list = [RequestParams( method=method, url=url, headers=kwargs.pop('headers', {}), trace_request_ctx=kwargs.pop('trace_request_ctx', None), kwargs=kwargs, ) for url in url_list] return self._make_requests( params_list=params_list, retry_options=retry_options, raise_for_status=raise_for_status, ) def _make_requests( self, params_list: List[RequestParams], retry_options: Optional[RetryOptionsBase] = None, raise_for_status: Optional[bool] = None, ) -> _RequestContext: if retry_options is None: retry_options = self._retry_options if raise_for_status is None: raise_for_status = self._raise_for_status return _RequestContext( request_func=self._client.request, params_list=params_list, logger=self._logger, retry_options=retry_options, raise_for_status=raise_for_status, ) async def __aenter__(self) -> 'RetryClient': return self async def __aexit__( self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType], ) -> None: await self.close() def __del__(self) -> None: if getattr(self, '_closed', None) is None: # in case object was not initialized (__init__ raised an exception) return if not self._closed: self._logger.warning("Aiohttp retry client was not closed")