Source code for aiohttp_client_cache.session

"""Core functions for cache configuration"""
import warnings
from contextlib import asynccontextmanager
from logging import getLogger

from aiohttp import ClientSession
from aiohttp.typedefs import StrOrURL

from aiohttp_client_cache.backends import CacheBackend
from aiohttp_client_cache.forge_utils import extend_signature, forge
from aiohttp_client_cache.response import AnyResponse

logger = getLogger(__name__)

[docs]class CacheMixin: """A mixin class for :py:class:`aiohttp.ClientSession` that adds caching support Args: cache: A cache backend object. See :py:module:`aiohttp_client_cache.backends` for options. If not provided, an in-memory cache will be used. """ @extend_signature(ClientSession.__init__) def __init__(self, *, cache: CacheBackend = None, **kwargs): super().__init__(**kwargs) # type: ignore self.cache = cache or CacheBackend()
[docs] @forge.copy(ClientSession._request) async def _request(self, method: str, str_or_url: StrOrURL, **kwargs) -> AnyResponse: """Wrapper around :py:meth:`.SessionClient._request` that adds caching""" cache_key = self.cache.create_key(method, str_or_url, **kwargs) # Attempt to fetch cached response; if missing or expired, fetch new one cached_response = await self.cache.get_response(cache_key) if cached_response: return cached_response else:'Cached response not found; making request to {str_or_url}') new_response = await super()._request(method, str_or_url, **kwargs) # type: ignore await await self.cache.save_response(cache_key, new_response) return new_response
[docs] @asynccontextmanager async def disable_cache(self): """Temporarily disable the cache Example: >>> session = CachedSession() >>> await session.get('') >>> async with session.disable_cache(): >>> # Will return a new response, not a cached one >>> await session.get('') """ self.cache.disabled = True yield self.cache.disabled = False
[docs] async def delete_expired_responses(self): """Remove all expired responses from the cache""" await self.cache.delete_expired_responses()
# Ignore aiohttp warning: "Inheritance from ClientSession is discouraged" # Since only _request() is overridden, there is minimal chance of breakage, but still possible with warnings.catch_warnings(): warnings.simplefilter("ignore")
[docs] class CachedSession(CacheMixin, ClientSession): """A drop-in replacement for :py:class:`aiohttp.ClientSession` that adds caching support"""