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web框架之Tornado

  Tornado 是 FriendFeed 使用的可扩展的非阻塞式 web 服务器及其相关工具的开源版本。

  这个 Web 框架看起来有些像web.py 或者 Google 的 webapp,不过为了能有效利用非阻塞式服务器环境,这个 Web 框架还包含了一些相关的有用工具 和优化。

  Tornado 和现在的主流 Web 服务器框架(包括大多数 Python 的框架)有着明显的区别:它是非阻塞式服务器,而且速度相当快。

  得利于其 非阻塞的方式和对 epoll 的运用,Tornado 每秒可以处理数以千计的连接,这意味着对于实时 Web 服务来说,Tornado 是一个理想的 Web 框架。

  我们开发这个 Web 服务器的主要目的就是为了处理 FriendFeed 的实时功能 ——在 FriendFeed 的应用里每一个活动用户都会保持着一个服务器连接。(关于如何扩容 服务器,以处理数以千计的客户端的连接的问题,请参阅 C10K problem。)

一、快速上手

  

#!/usr/bin/env python# -*- coding:utf-8 -*-  import tornado.ioloopimport tornado.web    class MainHandler(tornado.web.RequestHandler):    def get(self):        self.write("Hello, world")  application = tornado.web.Application([    (r"/index", MainHandler),])    if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()

 

  第一步:执行脚本,监听 8888 端口

  第二步:浏览器客户端访问 /index  -->  http://127.0.0.1:8888/index

  第三步:服务器接受请求,并交由对应的类处理该请求

  第四步:类接受到请求之后,根据请求方式(post / get / delete ...)的不同调用并执行相应的方法

  第五步:方法返回值的字符串内容发送浏览器

  

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-#!/usr/bin/env python# -*- coding:utf-8 -*-import tornado.ioloopimport tornado.webfrom tornado import httpclientfrom tornado.web import asynchronousfrom tornado import genimport uimodules as mdimport uimethods as mtclass MainHandler(tornado.web.RequestHandler):        @asynchronous        @gen.coroutine        def get(self):            print start get             http = httpclient.AsyncHTTPClient()            http.fetch("http://127.0.0.1:8008/post/", self.callback)            self.write(end)        def callback(self, response):            print response.bodysettings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    ui_methods: mt,    ui_modules: md,}application = tornado.web.Application([    (r"/index", MainHandler),], **settings)if __name__ == "__main__":    application.listen(8009)    tornado.ioloop.IOLoop.instance().start()异步非阻塞实例
异步非阻塞实例

 

二、路由系统

  路由系统其实就是 url 和 类 的对应关系,这里不同于其他框架,其他很多框架均是 url 对应 函数,Tornado中每个url对应的是一个类。

  

#!/usr/bin/env python# -*- coding:utf-8 -*-  import tornado.ioloopimport tornado.web    class MainHandler(tornado.web.RequestHandler):    def get(self):        self.write("Hello, world")  class StoryHandler(tornado.web.RequestHandler):    def get(self, story_id):        self.write("You requested the story " + story_id)  class BuyHandler(tornado.web.RequestHandler):    def get(self):        self.write("buy.wupeiqi.com/index")  application = tornado.web.Application([    (r"/index", MainHandler),    (r"/story/([0-9]+)", StoryHandler),])  application.add_handlers(buy.wupeiqi.com$, [    (r/index,BuyHandler),])  if __name__ == "__main__":    application.listen(80)    tornado.ioloop.IOLoop.instance().start()

 

 

三、模板

  Tornao中的模板语言和django中类似,模板引擎将模板文件载入内存,然后将数据嵌入其中,最终获取到一个完整的字符串,再将字符串返回给请求者。

  Tornado 的模板支持“控制语句”和“表达语句”,控制语句是使用 {% 和 %} 包起来的 例如 {% if len(items) > 2 %}。表达语句是使用 {{ 和 }} 包起来的,例如 {{ items[0] }}

  控制语句和对应的 Python 语句的格式基本完全相同。我们支持 ifforwhile 和 try,这些语句逻辑结束的位置需要用 {% end %} 做标记。还通过 extends 和 block 语句实现了模板继承。这些在 template 模块 的代码文档中有着详细的描述。

技术分享
<!DOCTYPE html><html><head>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>    <title>老男孩</title>    <link href="{{static_url("css/common.css")}}" rel="stylesheet" />    {% block CSS %}{% end %}</head><body>    <div class="pg-header">    </div>        {% block RenderBody %}{% end %}       <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>        {% block JavaScript %}{% end %}</body></html>layout.html
layout

 

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{% extends ‘layout.html‘%}{% block CSS %}    <link href="{{static_url("css/index.css")}}" rel="stylesheet" />{% end %}{% block RenderBody %}    <h1>Index</h1>    <ul>    {%  for item in li %}        <li>{{item}}</li>    {% end %}    </ul>{% end %}{% block JavaScript %}    {% end %}index.html
index

 

  

#!/usr/bin/env python# -*- coding:utf-8 -*-  import tornado.ioloopimport tornado.web    class MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(home/index.html)  settings = {    template_path: template,}  application = tornado.web.Application([    (r"/index", MainHandler),], **settings)    if __name__ == "__main__":    application.listen(80)    tornado.ioloop.IOLoop.instance().start()

 

在模板中默认提供了一些函数、字段、类以供模板使用:

  • escapetornado.escape.xhtml_escape 的別名
  • xhtml_escapetornado.escape.xhtml_escape 的別名
  • url_escapetornado.escape.url_escape 的別名
  • json_encodetornado.escape.json_encode 的別名
  • squeezetornado.escape.squeeze 的別名
  • linkifytornado.escape.linkify 的別名
  • datetime: Python 的 datetime 模组
  • handler: 当前的 RequestHandler 对象
  • requesthandler.request 的別名
  • current_userhandler.current_user 的別名
  • localehandler.locale 的別名
  • _handler.locale.translate 的別名
  • static_url: for handler.static_url 的別名
  • xsrf_form_htmlhandler.xsrf_form_html 的別名

  Tornado默认提供的这些功能其实本质上就是 UIMethod 和 UIModule,我们也可以自定义从而实现类似于Django的simple_tag的功能:

  1、定义

技术分享
# uimethods.py def tab(self):    return UIMethod
uimethods

 

#!/usr/bin/env python# -*- coding:utf-8 -*-from tornado.web import UIModulefrom tornado import escapeclass custom(UIModule):    def render(self, *args, **kwargs):        return escape.xhtml_escape(<h1>wupeiqi</h1>)        #return escape.xhtml_escape(‘<h1>wupeiqi</h1>‘)uimodules.py

 

2、注册

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-#!/usr/bin/env python# -*- coding:utf-8 -*-import tornado.ioloopimport tornado.webfrom tornado.escape import linkifyimport uimodules as mdimport uimethods as mtclass MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(index.html)settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    ui_methods: mt,    ui_modules: md,}application = tornado.web.Application([    (r"/index", MainHandler),], **settings)if __name__ == "__main__":    application.listen(8009)    tornado.ioloop.IOLoop.instance().start()main.py
main

 

3、使用

技术分享
<!DOCTYPE html><html><head lang="en">    <meta charset="UTF-8">    <title></title>    <link href="{{static_url("commons.css")}}" rel="stylesheet" /></head><body>    <h1>hello</h1>    {% module custom(123) %}    {{ tab() }}</body>
index

 

 

四、实用功能

1、静态文件

  对于静态文件,可以配置静态文件的目录和前段使用时的前缀,并且Tornaodo还支持静态文件缓存。

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*- import tornado.ioloopimport tornado.web  class MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(‘home/index.html‘) settings = {    ‘template_path‘: ‘template‘,    ‘static_path‘: ‘static‘,    ‘static_url_prefix‘: ‘/static/‘,} application = tornado.web.Application([    (r"/index", MainHandler),], **settings)  if __name__ == "__main__":    application.listen(80)    tornado.ioloop.IOLoop.instance().start()main.py
main
技术分享
<!DOCTYPE html><html><head lang="en">    <meta charset="UTF-8">    <title></title>    <link href="{{static_url("commons.css")}}" rel="stylesheet" /></head><body>    <h1>hello</h1></body></html>index.html
index

备注:静态文件缓存的实现

 

技术分享
def get_content_version(cls, abspath):        """Returns a version string for the resource at the given path.        This class method may be overridden by subclasses.  The        default implementation is a hash of the file‘s contents.        .. versionadded:: 3.1        """        data = cls.get_content(abspath)        hasher = hashlib.md5()        if isinstance(data, bytes):            hasher.update(data)        else:            for chunk in data:                hasher.update(chunk)        return hasher.hexdigest()
静态文件缓存源码

 

2、csrf

  Tornado中的夸张请求伪造和Django中的相似,跨站伪造请求(Cross-site request forgery)

 

技术分享
settings = {    "xsrf_cookies": True,}application = tornado.web.Application([    (r"/", MainHandler),    (r"/login", LoginHandler),], **settings)配置
配置
技术分享
<form action="/new_message" method="post">  {{ xsrf_form_html() }}  <input type="text" name="message"/>  <input type="submit" value="Post"/></form>
普通表单使用

 

技术分享
function getCookie(name) {    var r = document.cookie.match("\\b" + name + "=([^;]*)\\b");    return r ? r[1] : undefined;}jQuery.postJSON = function(url, args, callback) {    args._xsrf = getCookie("_xsrf");    $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST",        success: function(response) {        callback(eval("(" + response + ")"));    }});};
Ajax使用

注:Ajax使用时,本质上就是去获取本地的cookie,携带cookie再来发送请求

3、cookie

  Tornado中可以对cookie进行操作,并且还可以对cookie进行签名以放置伪造。

  a、基本操作

class MainHandler(tornado.web.RequestHandler):    def get(self):        if not self.get_cookie("mycookie"):            self.set_cookie("mycookie", "myvalue")            self.write("Your cookie was not set yet!")        else:            self.write("Your cookie was set!")

 

  b、签名

    Cookie 很容易被恶意的客户端伪造。加入你想在 cookie 中保存当前登陆用户的 id 之类的信息,你需要对 cookie 作签名以防止伪造。Tornado 通过 set_secure_cookie 和 get_secure_cookie 方法直接支持了这种功能。 要使用这些方法,你需要在创建应用时提供一个密钥,名字为 cookie_secret。 你可以把它作为一个关键词参数传入应用的设置中:

技术分享
class MainHandler(tornado.web.RequestHandler):    def get(self):        if not self.get_secure_cookie("mycookie"):            self.set_secure_cookie("mycookie", "myvalue")            self.write("Your cookie was not set yet!")        else:            self.write("Your cookie was set!")             application = tornado.web.Application([    (r"/", MainHandler),], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")Code
Code

 

技术分享
def _create_signature_v1(secret, *parts):    hash = hmac.new(utf8(secret), digestmod=hashlib.sha1)    for part in parts:        hash.update(utf8(part))    return utf8(hash.hexdigest())def _create_signature_v2(secret, s):    hash = hmac.new(utf8(secret), digestmod=hashlib.sha256)    hash.update(utf8(s))    return utf8(hash.hexdigest())
内部算法

 

技术分享
def create_signed_value(secret, name, value, version=None, clock=None,                        key_version=None):    if version is None:        version = DEFAULT_SIGNED_VALUE_VERSION    if clock is None:        clock = time.time    timestamp = utf8(str(int(clock())))    value = http://www.mamicode.com/base64.b64encode(utf8(value))"|".join([value, timestamp, signature])        return value    elif version == 2:        # The v2 format consists of a version number and a series of        # length-prefixed fields "%d:%s", the last of which is a        # signature, all separated by pipes.  All numbers are in        # decimal format with no leading zeros.  The signature is an        # HMAC-SHA256 of the whole string up to that point, including        # the final pipe.        #        # The fields are:        # - format version (i.e. 2; no length prefix)        # - key version (integer, default is 0)        # - timestamp (integer seconds since epoch)        # - name (not encoded; assumed to be ~alphanumeric)        # - value (base64-encoded)        # - signature (hex-encoded; no length prefix)        def format_field(s):            return utf8("%d:" % len(s)) + utf8(s)        to_sign = b"|".join([            b"2",            format_field(str(key_version or 0)),            format_field(timestamp),            format_field(name),            format_field(value),            b‘‘])        if isinstance(secret, dict):            assert key_version is not None, ‘Key version must be set when sign key dict is used‘            assert version >= 2, ‘Version must be at least 2 for key version support‘            secret = secret[key_version]        signature = _create_signature_v2(secret, to_sign)        return to_sign + signature    else:        raise ValueError("Unsupported version %d" % version)
内部算法-加密

 

技术分享
def _decode_signed_value_v1(secret, name, value, max_age_days, clock):    parts = utf8(value).split(b"|")    if len(parts) != 3:        return None    signature = _create_signature_v1(secret, name, parts[0], parts[1])    if not _time_independent_equals(parts[2], signature):        gen_log.warning("Invalid cookie signature %r", value)        return None    timestamp = int(parts[1])    if timestamp < clock() - max_age_days * 86400:        gen_log.warning("Expired cookie %r", value)        return None    if timestamp > clock() + 31 * 86400:        # _cookie_signature does not hash a delimiter between the        # parts of the cookie, so an attacker could transfer trailing        # digits from the payload to the timestamp without altering the        # signature.  For backwards compatibility, sanity-check timestamp        # here instead of modifying _cookie_signature.        gen_log.warning("Cookie timestamp in future; possible tampering %r",                        value)        return None    if parts[1].startswith(b"0"):        gen_log.warning("Tampered cookie %r", value)        return None    try:        return base64.b64decode(parts[0])    except Exception:        return Nonedef _decode_fields_v2(value):    def _consume_field(s):        length, _, rest = s.partition(b‘:‘)        n = int(length)        field_value = http://www.mamicode.com/rest[:n]"malformed v2 signed value field")        rest = rest[n + 1:]        return field_value, rest    rest = value[2:]  # remove version number    key_version, rest = _consume_field(rest)    timestamp, rest = _consume_field(rest)    name_field, rest = _consume_field(rest)    value_field, passed_sig = _consume_field(rest)    return int(key_version), timestamp, name_field, value_field, passed_sigdef _decode_signed_value_v2(secret, name, value, max_age_days, clock):    try:        key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)    except ValueError:        return None    signed_string = value[:-len(passed_sig)]    if isinstance(secret, dict):        try:            secret = secret[key_version]        except KeyError:            return None    expected_sig = _create_signature_v2(secret, signed_string)    if not _time_independent_equals(passed_sig, expected_sig):        return None    if name_field != utf8(name):        return None    timestamp = int(timestamp)    if timestamp < clock() - max_age_days * 86400:        # The signature has expired.        return None    try:        return base64.b64decode(value_field)    except Exception:        return Nonedef get_signature_key_version(value):    value = utf8(value)    version = _get_version(value)    if version < 2:        return None    try:        key_version, _, _, _, _ = _decode_fields_v2(value)    except ValueError:        return None    return key_version
内部算法-解密

签名Cookie的本质是:

写cookie过程:

  • 将值进行base64加密
  • 对除值以外的内容进行签名,哈希算法(无法逆向解析)
  • 拼接 签名 + 加密值

读cookie过程:

  • 读取 签名 + 加密值
  • 对签名进行验证
  • base64解密,获取值内容

注:许多API验证机制和安全cookie的实现机制相同。

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*- import tornado.ioloopimport tornado.web  class MainHandler(tornado.web.RequestHandler):     def get(self):        login_user = self.get_secure_cookie("login_user", None)        if login_user:            self.write(login_user)        else:            self.redirect(/login)  class LoginHandler(tornado.web.RequestHandler):    def get(self):        self.current_user()         self.render(login.html, **{status: ‘‘})     def post(self, *args, **kwargs):         username = self.get_argument(name)        password = self.get_argument(pwd)        if username == wupeiqi and password == 123:            self.set_secure_cookie(login_user, 武沛齐)            self.redirect(/)        else:            self.render(login.html, **{status: 用户名或密码错误}) settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    cookie_secret: aiuasdhflashjdfoiuashdfiuh} application = tornado.web.Application([    (r"/index", MainHandler),    (r"/login", LoginHandler),], **settings)  if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()
Demo-基于cookie进行用户验证

 

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*- import tornado.ioloopimport tornado.web class BaseHandler(tornado.web.RequestHandler):     def get_current_user(self):        return self.get_secure_cookie("login_user") class MainHandler(BaseHandler):     @tornado.web.authenticated    def get(self):        login_user = self.current_user        self.write(login_user)   class LoginHandler(tornado.web.RequestHandler):    def get(self):        self.current_user()         self.render(login.html, **{status: ‘‘})     def post(self, *args, **kwargs):         username = self.get_argument(name)        password = self.get_argument(pwd)        if username == wupeiqi and password == 123:            self.set_secure_cookie(login_user, 武沛齐)            self.redirect(/)        else:            self.render(login.html, **{status: 用户名或密码错误}) settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    cookie_secret: aiuasdhflashjdfoiuashdfiuh,    login_url: /login} application = tornado.web.Application([    (r"/index", MainHandler),    (r"/login", LoginHandler),], **settings)  if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()
Demo-Toando内部提供基于cookie进行用户验证

 

 

 

4、Ajax上传文件

技术分享
<!DOCTYPE html><html><head lang="en">    <meta charset="UTF-8">    <title></title></head><body>    <input type="file" id="img" />    <input type="button" onclick="UploadFile();" />    <script>        function UploadFile(){            var fileObj = document.getElementById("img").files[0];            var form = new FormData();            form.append("k1", "v1");            form.append("fff", fileObj);            var xhr = new XMLHttpRequest();            xhr.open("post", /index, true);            xhr.send(form);        }    </script></body></html>
Html

 

 

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-#!/usr/bin/env python# -*- coding:utf-8 -*-import tornado.ioloopimport tornado.webclass MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(‘index.html‘)    def post(self, *args, **kwargs):        file_metas = self.request.files["fff"]        # print(file_metas)        for meta in file_metas:            file_name = meta[‘filename‘]            with open(file_name,‘wb‘) as up:                up.write(meta[‘body‘])settings = {    ‘template_path‘: ‘template‘,}application = tornado.web.Application([    (r"/index", MainHandler),], **settings)if __name__ == "__main__":    application.listen(8000)    tornado.ioloop.IOLoop.instance().start()
Python

 

 

 

 

技术分享
var fileObj = $("#img")[0].files[0];var form = new FormData();form.append("k1", "v1");form.append("fff", fileObj);$.ajax({    type:POST,    url: /index,    data: form,    processData: false,  // tell jQuery not to process the data    contentType: false,  // tell jQuery not to set contentType    success: function(arg){        console.log(arg);    }})
jQuery Ajax Upload

 

 

 

 

五、扩展功能

1、自定义Session

a.知识储备

  

#!/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‘] 

b.session实现机制

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-  import tornado.ioloopimport tornado.webfrom hashlib import sha1import os, time  session_container = {}  create_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):        return session_container[self._id][key]      def __setitem__(self, key, value):        if session_container.has_key(self._id):            session_container[self._id][key] = value        else:            session_container[self._id] = {key: value}      def __delitem__(self, key):        del session_container[self._id][key]    class BaseHandler(tornado.web.RequestHandler):      def initialize(self):        # my_session[‘k1‘]访问 __getitem__ 方法        self.my_session = Session(self)    class MainHandler(BaseHandler):      def get(self):        print self.my_session[c_user]        print self.my_session[c_card]        self.write(index)  class LoginHandler(BaseHandler):      def get(self):        self.render(login.html, **{status: ‘‘})      def post(self, *args, **kwargs):          username = self.get_argument(name)        password = self.get_argument(pwd)        if username == wupeiqi and password == 123:              self.my_session[c_user] = wupeiqi            self.my_session[c_card] = 12312312309823012              self.redirect(/index)        else:            self.render(login.html, **{status: 用户名或密码错误})  settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    cookie_secret: aiuasdhflashjdfoiuashdfiuh,    login_url: /login}  application = tornado.web.Application([    (r"/index", MainHandler),    (r"/login", LoginHandler),], **settings)    if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()
session实现机制

c. Session框架

技术分享
#!/usr/bin/env python#coding:utf-8import sysimport mathfrom bisect import bisectif sys.version_info >= (2, 5):    import hashlib    md5_constructor = hashlib.md5else:    import md5    md5_constructor = md5.newclass HashRing(object):    """一致性哈希"""        def __init__(self,nodes):        ‘‘‘初始化        nodes : 初始化的节点,其中包含节点已经节点对应的权重                默认每一个节点有32个虚拟节点                对于权重,通过多创建虚拟节点来实现                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(该节点已经存在.)                self.ring[key] = node                self._sorted_keys.append(key)                def add_node(self,node):        ‘‘‘ 新建节点        node : 要添加的节点,格式为:{‘host‘:‘127.0.0.1:8002‘,‘weight‘:1},其中第一个元素表示节点,第二个元素表示该节点的权重。        ‘‘‘        node = node.get(host,None)        if not node:                raise Exception(节点的地址不能为空.)                        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(该节点已经存在.)            self.ring[key] = node            self._sorted_keys.append(key)            def remove_node(self,node):        ‘‘‘ 移除节点        node : 要移除的节点 ‘127.0.0.1:8000‘        ‘‘‘        for key,value in self.ring.items():            if value =http://www.mamicode.com/= node:                del self.ring[key]                self._sorted_keys.remove(key)        def get_node(self,string_key):        ‘‘‘获取 string_key 所在的节点‘‘‘        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):        ‘‘‘获取 string_key 所在的节点的索引‘‘‘        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"""
一致性哈希
技术分享
from hashlib import sha1import 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):        # 根据 self._id ,在一致性哈西中找到其对应的服务器IP        # 找到相对应的redis服务器,如: r = redis.StrictRedis(host=‘localhost‘, port=6379, db=0)        # 使用python redis api 链接        # 获取数据,即:        # return self._redis.hget(self._id, name)    def __setitem__(self, key, value):        # 根据 self._id ,在一致性哈西中找到其对应的服务器IP        # 使用python redis api 链接        # 设置session        # self._redis.hset(self._id, name, value)    def __delitem__(self, key):        # 根据 self._id 找到相对应的redis服务器        # 使用python redis api 链接        # 删除,即:        return self._redis.hdel(self._id, name)        
Session

 

2、自定义模型版定

模型绑定有两个主要功能:

  • 自动生成html表单
  • 用户输入验证

在之前学习的Django中为程序员提供了非常便捷的模型绑定功能,但是在Tornado中,一切需要自己动手!!!

技术分享
<!DOCTYPE html><html><head lang="en">    <meta charset="UTF-8">    <title></title>    <link href=http://www.mamicode.com/"{{static_url("commons.css")}}" rel="stylesheet" /></head><body>    <h1>hello</h1>    <form action="/index" method="post">        <p>hostname: <input type="text" name="host" /> </p>        <p>ip: <input type="text" name="ip" /> </p>        <p>port: <input type="text" name="port" /> </p>        <p>phone: <input type="text" name="phone" /> </p>        <input type="submit" />    </form></body></html>html
html
技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-  import tornado.ioloopimport tornado.webfrom hashlib import sha1import os, timeimport re    class MainForm(object):    def __init__(self):        self.host = "(.*)"        self.ip = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"        self.port = (\d+)        self.phone = ^1[3|4|5|8][0-9]\d{8}$      def check_valid(self, request):        form_dict = self.__dict__        for key, regular in form_dict.items():            post_value = request.get_argument(key)            # 让提交的数据 和 定义的正则表达式进行匹配            ret = re.match(regular, post_value)            print key,ret,post_value    class MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(index.html)    def post(self, *args, **kwargs):        obj = MainForm()        result = obj.check_valid(self)        self.write(ok)      settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    cookie_secret: aiuasdhflashjdfoiuashdfiuh,    login_url: /login}  application = tornado.web.Application([    (r"/index", MainHandler),], **settings)    if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()
View Code

 

由于请求的验证时,需要考虑是否可以为空以及正则表达式的复用,所以:

技术分享
#!/usr/bin/env python# -*- coding:utf-8 -*-import tornado.ioloopimport tornado.webimport reclass Field(object):    def __init__(self, error_msg_dict, required):        self.id_valid = False        self.value = None        self.error = None        self.name = None        self.error_msg = error_msg_dict        self.required = required    def match(self, name, value):        self.name = name        if not self.required:            self.id_valid = True            self.value = value        else:            if not value:                if self.error_msg.get(required, None):                    self.error = self.error_msg[required]                else:                    self.error = "%s is required" % name            else:                ret = re.match(self.REGULAR, value)                if ret:                    self.id_valid = True                    self.value = ret.group()                else:                    if self.error_msg.get(valid, None):                        self.error = self.error_msg[valid]                    else:                        self.error = "%s is invalid" % nameclass IPField(Field):    REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"    def __init__(self, error_msg_dict=None, required=True):        error_msg = {}  # {‘required‘: ‘IP不能为空‘, ‘valid‘: ‘IP格式错误‘}        if error_msg_dict:            error_msg.update(error_msg_dict)        super(IPField, self).__init__(error_msg_dict=error_msg, required=required)class IntegerField(Field):    REGULAR = "^\d+$"    def __init__(self, error_msg_dict=None, required=True):        error_msg = {required: 数字不能为空, valid: 数字格式错误}        if error_msg_dict:            error_msg.update(error_msg_dict)        super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)class CheckBoxField(Field):    def __init__(self, error_msg_dict=None, required=True):        error_msg = {}  # {‘required‘: ‘IP不能为空‘, ‘valid‘: ‘IP格式错误‘}        if error_msg_dict:            error_msg.update(error_msg_dict)        super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)    def match(self, name, value):        self.name = name        if not self.required:            self.id_valid = True            self.value = value        else:            if not value:                if self.error_msg.get(required, None):                    self.error = self.error_msg[required]                else:                    self.error = "%s is required" % name            else:                if isinstance(name, list):                    self.id_valid = True                    self.value = value                else:                    if self.error_msg.get(valid, None):                        self.error = self.error_msg[valid]                    else:                        self.error = "%s is invalid" % nameclass FileField(Field):    REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$"    def __init__(self, error_msg_dict=None, required=True):        error_msg = {}  # {‘required‘: ‘数字不能为空‘, ‘valid‘: ‘数字格式错误‘}        if error_msg_dict:            error_msg.update(error_msg_dict)        super(FileField, self).__init__(error_msg_dict=error_msg, required=required)    def match(self, name, value):        self.name = name        self.value = []        if not self.required:            self.id_valid = True            self.value = value        else:            if not value:                if self.error_msg.get(required, None):                    self.error = self.error_msg[required]                else:                    self.error = "%s is required" % name            else:                m = re.compile(self.REGULAR)                if isinstance(value, list):                    for file_name in value:                        r = m.match(file_name)                        if r:                            self.value.append(r.group())                            self.id_valid = True                        else:                            self.id_valid = False                            if self.error_msg.get(valid, None):                                self.error = self.error_msg[valid]                            else:                                self.error = "%s is invalid" % name                            break                else:                    if self.error_msg.get(valid, None):                        self.error = self.error_msg[valid]                    else:                        self.error = "%s is invalid" % name    def save(self, request, upload_path=""):        file_metas = request.files[self.name]        for meta in file_metas:            file_name = meta[filename]            with open(file_name,wb) as up:                up.write(meta[body])class Form(object):    def __init__(self):        self.value_dict = {}        self.error_dict = {}        self.valid_status = True    def validate(self, request, depth=10, pre_key=""):        self.initialize()        self.__valid(self, request, depth, pre_key)    def initialize(self):        pass    def __valid(self, form_obj, request, depth, pre_key):        """        验证用户表单请求的数据        :param form_obj: Form对象(Form派生类的对象)        :param request: Http请求上下文(用于从请求中获取用户提交的值)        :param depth: 对Form内容的深度的支持        :param pre_key: Html中name属性值的前缀(多层Form时,内部递归时设置,无需理会)        :return: 是否验证通过,True:验证成功;False:验证失败        """        depth -= 1        if depth < 0:            return None        form_field_dict = form_obj.__dict__        for key, field_obj in form_field_dict.items():            print key,field_obj            if isinstance(field_obj, Form) or isinstance(field_obj, Field):                if isinstance(field_obj, Form):                    # 获取以key开头的所有的值,以参数的形式传至                    self.__valid(field_obj, request, depth, key)                    continue                if pre_key:                    key = "%s.%s" % (pre_key, key)                if isinstance(field_obj, CheckBoxField):                    post_value = request.get_arguments(key, None)                elif isinstance(field_obj, FileField):                    post_value = []                    file_list = request.request.files.get(key, None)                    for file_item in file_list:                        post_value.append(file_item[filename])                else:                    post_value = request.get_argument(key, None)                print post_value                # 让提交的数据 和 定义的正则表达式进行匹配                field_obj.match(key, post_value)                if field_obj.id_valid:                    self.value_dict[key] = field_obj.value                else:                    self.error_dict[key] = field_obj.error                    self.valid_status = Falseclass ListForm(object):    def __init__(self, form_type):        self.form_type = form_type        self.valid_status = True        self.value_dict = {}        self.error_dict = {}    def validate(self, request):        name_list = request.request.arguments.keys() + request.request.files.keys()        index = 0        flag = False        while True:            pre_key = "[%d]" % index            for name in name_list:                if name.startswith(pre_key):                    flag = True                    break            if flag:                form_obj = self.form_type()                form_obj.validate(request, depth=10, pre_key="[%d]" % index)                if form_obj.valid_status:                    self.value_dict[index] = form_obj.value_dict                else:                    self.error_dict[index] = form_obj.error_dict                    self.valid_status = False            else:                break            index += 1            flag = Falseclass MainForm(Form):    def __init__(self):        # self.ip = IPField(required=True)        # self.port = IntegerField(required=True)        # self.new_ip = IPField(required=True)        # self.second = SecondForm()        self.fff = FileField(required=True)        super(MainForm, self).__init__()## class SecondForm(Form):##     def __init__(self):#         self.ip = IPField(required=True)#         self.new_ip = IPField(required=True)##         super(SecondForm, self).__init__()class MainHandler(tornado.web.RequestHandler):    def get(self):        self.render(index.html)    def post(self, *args, **kwargs):        # for i in  dir(self.request):        #     print i        # print self.request.arguments        # print self.request.files        # print self.request.query        # name_list = self.request.arguments.keys() + self.request.files.keys()        # print name_list        # list_form = ListForm(MainForm)        # list_form.validate(self)        #        # print list_form.valid_status        # print list_form.value_dict        # print list_form.error_dict        # obj = MainForm()        # obj.validate(self)        #        # print "验证结果:", obj.valid_status        # print "符合验证结果:", obj.value_dict        # print "错误信息:"        # for key, item in obj.error_dict.items():        #     print key,item        # print self.get_arguments(‘favor‘),type(self.get_arguments(‘favor‘))        # print self.get_argument(‘favor‘),type(self.get_argument(‘favor‘))        # print type(self.get_argument(‘fff‘)),self.get_argument(‘fff‘)        # print self.request.files        # obj = MainForm()        # obj.validate(self)        # print obj.valid_status        # print obj.value_dict        # print obj.error_dict        # print self.request,type(self.request)        # obj.fff.save(self.request)        # from tornado.httputil import HTTPServerRequest        # name_list = self.request.arguments.keys() + self.request.files.keys()        # print name_list        # print self.request.files,type(self.request.files)        # print len(self.request.files.get(‘fff‘))                # obj = MainForm()        # obj.validate(self)        # print obj.valid_status        # print obj.value_dict        # print obj.error_dict        # obj.fff.save(self.request)        self.write(ok)settings = {    template_path: template,    static_path: static,    static_url_prefix: /static/,    cookie_secret: aiuasdhflashjdfoiuashdfiuh,    login_url: /login}application = tornado.web.Application([    (r"/index", MainHandler),], **settings)if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()
Form验证框架

 

web框架之Tornado