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面向?qū)ο蠡A(chǔ)

面向?qū)ο笾型ㄟ^索引的方式訪問對象，需要內(nèi)部實(shí)現(xiàn) __getitem__ 、__delitem__、__setitem__方法

#!/usr/bin/env python # -*- coding:utf-8 -*-class Foo(object): def __getitem__(self, key): print '__getitem__',key def __setitem__(self, key, value): print '__setitem__',key,value def __delitem__(self, key): print '__delitem__',key obj = Foo() result = obj['k1'] #obj['k2'] = 'wupeiqi' #del obj['k1']

Tornado擴(kuò)展

在tornado的源碼中,默認(rèn)執(zhí)行Handler的get/post等方法之前默認(rèn)會執(zhí)行 initialize方法，所以可以通過自定義的方式使得所有請求在處理前執(zhí)行操作.

class BaseHandler(tornado.web.RequestHandler):def initialize(self): self.xxoo = "wupeiqi" class MainHandler(BaseHandler): def get(self): print(self.xxoo) self.write('index') class IndexHandler(BaseHandler): def get(self): print(self.xxoo) self.write('index')

session

session其實(shí)就是定義在服務(wù)器端用于保存用戶回話的容器，其必須依賴cookie才能實(shí)現(xiàn)。

自定義session_1

#!/usr/bin/env python # -*- coding:utf-8 -*- import config from hashlib import sha1 import os import time #生成一個(gè)隨機(jī)的session_id create_session_id = lambda: sha1(bytes('%s%s' % (os.urandom(16), time.time()), encoding='utf-8')).hexdigest() #根據(jù)定義好的session存儲方式,選擇對應(yīng)的處理方式 class SessionFactory: @staticmethod def get_session_obj(handler): obj = None if config.SESSION_TYPE == "cache": obj = CacheSession(handler) elif config.SESSION_TYPE == "memcached": obj = MemcachedSession(handler) elif config.SESSION_TYPE == "redis": obj = RedisSession(handler) return obj class CacheSession: session_container = {} session_id = "__sessionId__" def __init__(self, handler): self.handler = handler client_random_str = handler.get_cookie(CacheSession.session_id, None) if client_random_str and client_random_str in CacheSession.session_container: self.random_str = client_random_str else: self.random_str = create_session_id() CacheSession.session_container[self.random_str] = {} expires_time = time.time() + config.SESSION_EXPIRES handler.set_cookie(CacheSession.session_id, self.random_str, expires=expires_time) def __getitem__(self, key): ret = CacheSession.session_container[self.random_str].get(key, None) return ret def __setitem__(self, key, value): CacheSession.session_container[self.random_str][key] = value def __delitem__(self, key): if key in CacheSession.session_container[self.random_str]: del CacheSession.session_container[self.random_str][key] class RedisSession: def __init__(self, handler): pass class MemcachedSession: def __init__(self, handler): pass

其中os.urandom(n): 返回n個(gè)隨機(jī)byte值的string，作為加密使用

自定義session_2(定義存儲方式)

session_app.py:

#!/usr/bin/env python # -*- coding:utf-8 -*- # pip3 install tornado import tornado.ioloop import tornado.web from Session.session import SessionHandler class MainHandler(SessionHandler,tornado.web.RequestHandler): def get(self): self.render('login.html') def post(self, *args, **kwargs): user = self.get_argument('username') pwd = self.get_argument('password') if user == 'alex' and pwd == '123': self.session_obj['is_login'] = True self.session_obj['user'] = user self.redirect('/index') else: self.redirect('/main') class IndexHandler(SessionHandler,tornado.web.RequestHandler): def get(self): current_user = self.session_obj['user'] del self.session_obj['user'] if current_user: self.write(current_user) else: self.write('滾') class MainHandler1(SessionHandler,tornado.web.RequestHandler): def get(self): self.write('ok') class MainHandler2(SessionHandler,tornado.web.RequestHandler): def get(self): print('ok') self.write('ok') # obj = MainHandler() # 執(zhí)行構(gòu)造方法 # obj.get() # func = getattr(obj, 'get') # func() application = tornado.web.Application([ (r"/main", MainHandler), (r"/index", IndexHandler), ]) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()

Session/session.py:

import hashlib import time from Session import confclass SessionHandler: def initialize(self): self.session_obj = SessionFacotory.get_session_obj(self) class SessionFacotory: @staticmethod def get_session_obj(handler): if conf.session_type == 'redis': return RedisSession(handler) elif conf.session_type == 'memcache': return RedisSession(handler) else: return MemorySession(handler) def md5(): m = hashlib.md5() m.update(bytes(str(time.time()),encoding='utf-8')) return m.hexdigest() class MemorySession: container = { } # self.r_str當(dāng)前用戶的隨機(jī)字符串 def __init__(self,handler): random_str = handler.get_cookie('___session_id___') if random_str: # 客戶端有cookie # 合法cookie if random_str in MemorySession.container: self.r_str = random_str else: # 非法cookie random_str = md5() MemorySession.container[random_str] = {} self.r_str = random_str else: # 客戶端無cookie，表示是新用戶的到來 random_str = md5() MemorySession.container[random_str] = {} self.r_str = random_str handler.set_cookie('___session_id___', random_str, expires=time.time() + 200) def __setitem__(self, key, value): MemorySession.container[self.r_str][key] = value def __getitem__(self, item): return MemorySession.container[self.r_str].get(item,None) def __delitem__(self, key): del MemorySession.container[self.r_str][key] class RedisSession: def __init__(self): pass def __getitem__(self, item): pass def __setitem__(self, key, value): pass def __delitem__(self, key): pass

Session/conf.py:

session_type = 'redis'

分布式session

一致性哈希:

#!/usr/bin/env python #coding:utf-8import sys import math from bisect import bisect if sys.version_info >= (2, 5): import hashlib md5_constructor = hashlib.md5 else: import md5 md5_constructor = md5.new class HashRing(object): """一致性哈希""" def __init__(self,nodes): '''初始化 nodes : 初始化的節(jié)點(diǎn)，其中包含節(jié)點(diǎn)已經(jīng)節(jié)點(diǎn)對應(yīng)的權(quán)重 默認(rèn)每一個(gè)節(jié)點(diǎn)有32個(gè)虛擬節(jié)點(diǎn) 對于權(quán)重，通過多創(chuàng)建虛擬節(jié)點(diǎn)來實(shí)現(xiàn) 如：nodes = [ {'host':'127.0.0.1:8000','weight':1}, {'host':'127.0.0.1:8001','weight':2}, {'host':'127.0.0.1:8002','weight':1}, ] ''' self.ring = dict() self._sorted_keys = [] self.total_weight = 0 self.__generate_circle(nodes) def __generate_circle(self,nodes): for node_info in nodes: self.total_weight += node_info.get('weight',1) for node_info in nodes: weight = node_info.get('weight',1) node = node_info.get('host',None) virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight) for i in xrange(0,int(virtual_node_count)): key = self.gen_key_thirty_two( '%s-%s' % (node, i) ) if self._sorted_keys.__contains__(key): raise Exception('該節(jié)點(diǎn)已經(jīng)存在.') self.ring[key] = node self._sorted_keys.append(key) def add_node(self,node): ''' 新建節(jié)點(diǎn) node : 要添加的節(jié)點(diǎn)，格式為：{'host':'127.0.0.1:8002','weight':1}，其中第一個(gè)元素表示節(jié)點(diǎn)，第二個(gè)元素表示該節(jié)點(diǎn)的權(quán)重。 ''' node = node.get('host',None) if not node: raise Exception('節(jié)點(diǎn)的地址不能為空.') weight = node.get('weight',1) self.total_weight += weight nodes_count = len(self._sorted_keys) + 1 virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight) for i in xrange(0,int(virtual_node_count)): key = self.gen_key_thirty_two( '%s-%s' % (node, i) ) if self._sorted_keys.__contains__(key): raise Exception('該節(jié)點(diǎn)已經(jīng)存在.') self.ring[key] = node self._sorted_keys.append(key) def remove_node(self,node): ''' 移除節(jié)點(diǎn) node : 要移除的節(jié)點(diǎn) '127.0.0.1:8000' ''' for key,value in self.ring.items(): if value == node: del self.ring[key] self._sorted_keys.remove(key) def get_node(self,string_key): '''獲取 string_key 所在的節(jié)點(diǎn)''' pos = self.get_node_pos(string_key) if pos is None: return None return self.ring[ self._sorted_keys[pos]].split(':') def get_node_pos(self,string_key): '''獲取 string_key 所在的節(jié)點(diǎn)的索引''' if not self.ring: return None key = self.gen_key_thirty_two(string_key) nodes = self._sorted_keys pos = bisect(nodes, key) return pos def gen_key_thirty_two(self, key): m = md5_constructor() m.update(key) return long(m.hexdigest(), 16) def gen_key_sixteen(self,key): b_key = self.__hash_digest(key) return self.__hash_val(b_key, lambda x: x) def __hash_val(self, b_key, entry_fn): return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] ) def __hash_digest(self, key): m = md5_constructor() m.update(key) return map(ord, m.digest()) """ nodes = [ {'host':'127.0.0.1:8000','weight':1}, {'host':'127.0.0.1:8001','weight':2}, {'host':'127.0.0.1:8002','weight':1}, ] ring = HashRing(nodes) result = ring.get_node('98708798709870987098709879087') print result """

分布式session:

from hashlib import sha1 import os, timecreate_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest() class Session(object): session_id = "__sessionId__" def __init__(self, request): session_value = request.get_cookie(Session.session_id) if not session_value: self._id = create_session_id() else: self._id = session_value request.set_cookie(Session.session_id, self._id) def __getitem__(self, key): # 根據(jù) self._id ，在一致性哈西中找到其對應(yīng)的服務(wù)器IP # 找到相對應(yīng)的redis服務(wù)器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0) # 使用python redis api 鏈接 # 獲取數(shù)據(jù)，即： # return self._redis.hget(self._id, name) def __setitem__(self, key, value): # 根據(jù) self._id ，在一致性哈西中找到其對應(yīng)的服務(wù)器IP # 使用python redis api 鏈接 # 設(shè)置session # self._redis.hset(self._id, name, value) def __delitem__(self, key): # 根據(jù) self._id 找到相對應(yīng)的redis服務(wù)器 # 使用python redis api 鏈接 # 刪除，即： return self._redis.hdel(self._id, name)

轉(zhuǎn)載于:https://www.cnblogs.com/shiluoliming/p/6659734.html

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