import asyncio
from typing import Dict
from aiocache.base import BaseCache
from aiocache.serializers import NullSerializer
class SimpleMemoryBackend(BaseCache):
"""
Wrapper around dict operations to use it as a cache backend
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self._cache: Dict[str, object] = {}
self._handlers: Dict[str, asyncio.TimerHandle] = {}
async def _get(self, key, encoding="utf-8", _conn=None):
return self._cache.get(key)
async def _gets(self, key, encoding="utf-8", _conn=None):
return await self._get(key, encoding=encoding, _conn=_conn)
async def _multi_get(self, keys, encoding="utf-8", _conn=None):
return [self._cache.get(key) for key in keys]
async def _set(self, key, value, ttl=None, _cas_token=None, _conn=None):
if _cas_token is not None and _cas_token != self._cache.get(key):
return 0
if key in self._handlers:
self._handlers[key].cancel()
self._cache[key] = value
if ttl:
loop = asyncio.get_running_loop()
self._handlers[key] = loop.call_later(ttl, self.__delete, key)
return True
async def _multi_set(self, pairs, ttl=None, _conn=None):
for key, value in pairs:
await self._set(key, value, ttl=ttl)
return True
async def _add(self, key, value, ttl=None, _conn=None):
if key in self._cache:
raise ValueError("Key {} already exists, use .set to update the value".format(key))
await self._set(key, value, ttl=ttl)
return True
async def _exists(self, key, _conn=None):
return key in self._cache
async def _increment(self, key, delta, _conn=None):
if key not in self._cache:
self._cache[key] = delta
else:
try:
self._cache[key] = int(self._cache[key]) + delta
except ValueError:
raise TypeError("Value is not an integer") from None
return self._cache[key]
async def _expire(self, key, ttl, _conn=None):
if key in self._cache:
handle = self._handlers.pop(key, None)
if handle:
handle.cancel()
if ttl:
loop = asyncio.get_running_loop()
self._handlers[key] = loop.call_later(ttl, self.__delete, key)
return True
return False
async def _delete(self, key, _conn=None):
return self.__delete(key)
async def _clear(self, namespace=None, _conn=None):
if namespace:
for key in list(self._cache):
if key.startswith(namespace):
self.__delete(key)
else:
self._cache = {}
self._handlers = {}
return True
async def _raw(self, command, *args, encoding="utf-8", _conn=None, **kwargs):
return getattr(self._cache, command)(*args, **kwargs)
async def _redlock_release(self, key, value):
if self._cache.get(key) == value:
return self.__delete(key)
return 0
def __delete(self, key):
if self._cache.pop(key, None) is not None:
handle = self._handlers.pop(key, None)
if handle:
handle.cancel()
return 1
return 0
class SimpleMemoryCache(SimpleMemoryBackend):
"""
Memory cache implementation with the following components as defaults:
- serializer: :class:`aiocache.serializers.NullSerializer`
- plugins: None
Config options are:
:param serializer: obj derived from :class:`aiocache.serializers.BaseSerializer`.
:param plugins: list of :class:`aiocache.plugins.BasePlugin` derived classes.
:param namespace: string to use as default prefix for the key used in all operations of
the backend. Default is None.
:param timeout: int or float in seconds specifying maximum timeout for the operations to last.
By default its 5.
"""
NAME = "memory"
def __init__(self, serializer=None, **kwargs):
super().__init__(serializer=serializer or NullSerializer(), **kwargs)
@classmethod
def parse_uri_path(cls, path):
return {}