Session for Tornado(Redis) - 代码分享

Session for Tornado(Redis) - 代码分享

 

Session for Tornado(Redis)

session id的生成借用了web.py。
使用了 redis 的 hash 储存。
只有在为session赋值的时候才会生成session_id，是为了必要的情况下的使用（例如oAuth2的state和验证码） 

[代码] [Python]代码

#coding=utf8

import os, time
from core.options import options
from hashlib import sha1

class Session(object):
    _prefix = "_session:"
    _id = None
    _skip = ['_redis','_request','_id']
    def __init__(self,request):
        self._redis = request.redis
        self._request = request
        #init session id
        id = request.get_secure_cookie('sessionid')
        if id and self._redis.exists(id):
            self._id = id

    def init_session(self):
        """初始化"""
        if not self._id:
            self._id = self.generate_session_id()
            self._request.set_secure_cookie('sessionid',self._id)
        #延期过期时间
        self._redis.hset(self._id,'lastActive',time.time())
        self._redis.expire(self._id,options.session_maxlifetime)

    def generate_session_id(self):
        """Generate a random id for session"""
        secret_key = self._request.settings['cookie_secret']
        ip = self._request.request.remote_ip
        while True:
            rand = os.urandom(16)
            now = time.time()
            sessionid = sha1("%s%s%s%s" % (rand, now,ip, secret_key))
            sessionid = self._prefix + sessionid.hexdigest()
            if not self._redis.exists(sessionid):
                break
        return sessionid

    def __getattr__(self, name):
        if self._id:
            return self._redis.hget(self._id,name)
        return object.__getattribute__(self, name)

    def __setattr__(self, name, value):
        if not name in self._skip:
            self.init_session()
            self._redis.hset(self._id,name,value)
        object.__setattr__(self, name, value)

    def __delattr__(self, name):
        if not name in self._skip:
            return self._redis.hdel(self._id,name)
        object.__delattr__(self, name)