import json
import uuid
from time import time
from . import AbstractStorage, Session
class MemcachedStorage(AbstractStorage):
"""Memcached storage"""
def __init__(self, memcached_conn, *, cookie_name="AIOHTTP_SESSION",
domain=None, max_age=None, path='/',
secure=None, httponly=True,
key_factory=lambda: uuid.uuid4().hex,
encoder=json.dumps, decoder=json.loads):
super().__init__(cookie_name=cookie_name, domain=domain,
max_age=max_age, path=path, secure=secure,
httponly=httponly,
encoder=encoder, decoder=decoder)
self._key_factory = key_factory
self.conn = memcached_conn
async def load_session(self, request):
cookie = self.load_cookie(request)
if cookie is None:
return Session(None, data=None, new=True, max_age=self.max_age)
else:
key = str(cookie)
stored_key = (self.cookie_name + '_' + key).encode('utf-8')
data = await self.conn.get(stored_key)
if data is None:
return Session(None, data=None,
new=True, max_age=self.max_age)
data = data.decode('utf-8')
try:
data = self._decoder(data)
except ValueError:
data = None
return Session(key, data=data, new=False, max_age=self.max_age)
async def save_session(self, request, response, session):
key = session.identity
if key is None:
key = self._key_factory()
self.save_cookie(response, key,
max_age=session.max_age)
else:
if session.empty:
self.save_cookie(response, '',
max_age=session.max_age)
else:
key = str(key)
self.save_cookie(response, key,
max_age=session.max_age)
data = self._encoder(self._get_session_data(session))
max_age = session.max_age
# https://github.com/memcached/memcached/wiki/Programming#expiration
# "Expiration times can be set from 0, meaning "never expire", to
# 30 days. Any time higher than 30 days is interpreted as a Unix
# timestamp date. If you want to expire an object on January 1st of
# next year, this is how you do that."
if max_age is None:
expire = 0
elif max_age > 30*24*60*60:
expire = int(time()) + max_age
else:
expire = max_age
stored_key = (self.cookie_name + '_' + key).encode('utf-8')
await self.conn.set(
stored_key, data.encode('utf-8'),
exptime=expire)
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