Web框架之Tornado

時間 2019-11-11

標籤 web 框架 tornado 欄目 HTML 简体版

原文原文鏈接

　　Tornado 是 FriendFeed 使用的可擴展的非阻塞式 web 服務器及其相關工具的開源版本。這個 Web 框架看起來有些像web.py 或者 Google 的 webapp，不過爲了能有效利用非阻塞式服務器環境，這個 Web 框架還包含了一些相關的有用工具和優化。css

　　Tornado 和如今的主流 Web 服務器框架（包括大多數 Python 的框架）有着明顯的區別：它是非阻塞式服務器，並且速度至關快。得利於其非阻塞的方式和對 epoll 的運用，Tornado 每秒能夠處理數以千計的鏈接，這意味着對於實時 Web 服務來講，Tornado 是一個理想的 Web 框架。咱們開發這個 Web 服務器的主要目的就是爲了處理 FriendFeed 的實時功能 ——在 FriendFeed 的應用裏每個活動用戶都會保持着一個服務器鏈接。（關於如何擴容服務器，以處理數以千計的客戶端的鏈接的問題，請參閱 C10K problem。）html

 
         pip install tornado 
        
         源碼安裝 
        
         https: 
         / 
         / 
         pypi.python.org 
         / 
         packages 
         / 
         source 
         / 
         t 
         / 
         tornado 
         / 
         tornado 
         - 
         4.3 
         .tar.gz

1、快速上手node

 
         #!/usr/bin/env python 
        
         # -*- coding:utf-8 -*- 
        
         import 
         tornado.ioloop 
        
         import 
         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：執行腳本，監聽 8888 端口python

第二步：瀏覽器客戶端訪問 /index --> http://127.0.0.1:8888/indexjquery

第三步：服務器接受請求，並交由對應的類處理該請求git

第四步：類接受到請求以後，根據請求方式（post / get / delete ...）的不一樣調用並執行相應的方法程序員

第五步：方法返回值的字符串內容發送瀏覽器github

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #!/usr/bin/env python
 4 # -*- coding:utf-8 -*-
 5 
 6 import tornado.ioloop
 7 import tornado.web
 8 from tornado import httpclient
 9 from tornado.web import asynchronous
10 from tornado import gen
11 
12 import uimodules as md
13 import uimethods as mt
14 
15 class MainHandler(tornado.web.RequestHandler):
16         @asynchronous
17         @gen.coroutine
18         def get(self):
19             print 'start get '
20             http = httpclient.AsyncHTTPClient()
21             http.fetch("http://127.0.0.1:8008/post/", self.callback)
22             self.write('end')
23 
24         def callback(self, response):
25             print response.body
26 
27 settings = {
28     'template_path': 'template',
29     'static_path': 'static',
30     'static_url_prefix': '/static/',
31     'ui_methods': mt,
32     'ui_modules': md,
33 }
34 
35 application = tornado.web.Application([
36     (r"/index", MainHandler),
37 ], **settings)
38 
39 
40 if __name__ == "__main__":
41     application.listen(8009)
42     tornado.ioloop.IOLoop.instance().start()

異步非阻塞實例

2、路由系統web

路由系統其實就是 url 和類的對應關係，這裏不一樣於其餘框架，其餘不少框架均是 url 對應函數，Tornado中每一個url對應的是一個類。ajax

 
         #!/usr/bin/env python 
        
         # -*- coding:utf-8 -*- 
        
         import 
         tornado.ioloop 
        
         import 
         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()

3、模板

Tornao中的模板語言和django中相似，模板引擎將模板文件載入內存，而後將數據嵌入其中，最終獲取到一個完整的字符串，再將字符串返回給請求者。

Tornado 的模板支持「控制語句」和「表達語句」，控制語句是使用 {% 和 %} 包起來的例如 {% if len(items) > 2 %}。表達語句是使用 {{ 和 }} 包起來的，例如 {{ items[0] }}。

控制語句和對應的 Python 語句的格式基本徹底相同。咱們支持 if、for、while 和 try，這些語句邏輯結束的位置須要用 {% end %} 作標記。還經過 extends 和 block 語句實現了模板繼承。這些在 template 模塊的代碼文檔中有着詳細的描述

 1 <!DOCTYPE html>
 2 <html>
 3 <head>
 4     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
 5     <title>老男孩</title>
 6     <link href="{{static_url("css/common.css")}}" rel="stylesheet" />
 7     {% block CSS %}{% end %}
 8 </head>
 9 <body>
10 
11     <div class="pg-header">
12 
13     </div>
14     
15     {% block RenderBody %}{% end %}
16    
17     <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script>
18     
19     {% block JavaScript %}{% end %}
20 </body>
21 </html>

layout.html

 1 {% extends 'layout.html'%}
 2 {% block CSS %}
 3     <link href="{{static_url("css/index.css")}}" rel="stylesheet" />
 4 {% end %}
 5 
 6 {% block RenderBody %}
 7     <h1>Index</h1>
 8 
 9     <ul>
10     {%  for item in li %}
11         <li>{{item}}</li>
12     {% end %}
13     </ul>
14 
15 {% end %}
16 
17 {% block JavaScript %}
18     
19 {% end %}

index.html

 1 import tornado.ioloop
 2 import tornado.web
 3   
 4   
 5 class MainHandler(tornado.web.RequestHandler):
 6     def get(self):
 7         self.render('home/index.html')
 8   
 9 settings = {
10     'template_path': 'template',
11 }
12   
13 application = tornado.web.Application([
14     (r"/index", MainHandler),
15 ], **settings)
16   
17   
18 if __name__ == "__main__":
19     application.listen(80)
20     tornado.ioloop.IOLoop.instance().start()

在模板中默認提供了一些函數、字段、類以供模板使用：

escape: tornado.escape.xhtml_escape 的別名
xhtml_escape: tornado.escape.xhtml_escape 的別名
url_escape: tornado.escape.url_escape 的別名
json_encode: tornado.escape.json_encode 的別名
squeeze: tornado.escape.squeeze 的別名
linkify: tornado.escape.linkify 的別名
datetime: Python 的 datetime 模組
handler: 當前的 RequestHandler 對象
request: handler.request 的別名
current_user: handler.current_user 的別名
locale: handler.locale 的別名
_: handler.locale.translate 的別名
static_url: for handler.static_url 的別名
xsrf_form_html: handler.xsrf_form_html 的別名

Tornado默認提供的這些功能其實本質上就是 UIMethod 和 UIModule，咱們也能夠自定義從而實現相似於Django的simple_tag的功能：
一、定義

1 # uimethods.py
2  
3 def tab(self):
4     return 'UIMethod'

 1 #uimodules.py
 2 
 3 from tornado.web import UIModule
 4 from tornado import escape
 5 
 6 class custom(UIModule):
 7 
 8     def render(self, *args, **kwargs):
 9         return escape.xhtml_escape('<h1>wupeiqi</h1>')
10         #return escape.xhtml_escape('<h1>wupeiqi</h1>')

二、註冊

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 #!/usr/bin/env python
 4 # -*- coding:utf-8 -*-
 5 
 6 import tornado.ioloop
 7 import tornado.web
 8 from tornado.escape import linkify
 9 import uimodules as md
10 import uimethods as mt
11 
12 class MainHandler(tornado.web.RequestHandler):
13     def get(self):
14         self.render('index.html')
15 
16 settings = {
17     'template_path': 'template',
18     'static_path': 'static',
19     'static_url_prefix': '/static/',
20     'ui_methods': mt,
21     'ui_modules': md,
22 }
23 
24 application = tornado.web.Application([
25     (r"/index", MainHandler),
26 ], **settings)
27 
28 
29 if __name__ == "__main__":
30     application.listen(8009)
31     tornado.ioloop.IOLoop.instance().start()

main.py

三、使用

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10     {% module custom(123) %}
11     {{ tab() }}
12 </body>

index.html

4、實用功能

一、靜態文件

對於靜態文件，能夠配置靜態文件的目錄和前段使用時的前綴，而且Tornaodo還支持靜態文件緩存。

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7  
 8 class MainHandler(tornado.web.RequestHandler):
 9     def get(self):
10         self.render('home/index.html')
11  
12 settings = {
13     'template_path': 'template',
14     'static_path': 'static',
15     'static_url_prefix': '/static/',
16 }
17  
18 application = tornado.web.Application([
19     (r"/index", MainHandler),
20 ], **settings)
21  
22  
23 if __name__ == "__main__":
24     application.listen(80)
25     tornado.ioloop.IOLoop.instance().start()

main.py

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10 </body>
11 </html>

index.html

備註：靜態文件緩存的實現

 1 def get_content_version(cls, abspath):
 2         """Returns a version string for the resource at the given path.
 3 
 4         This class method may be overridden by subclasses.  The
 5         default implementation is a hash of the file's contents.
 6 
 7         .. versionadded:: 3.1
 8         """
 9         data = cls.get_content(abspath)
10         hasher = hashlib.md5()
11         if isinstance(data, bytes):
12             hasher.update(data)
13         else:
14             for chunk in data:
15                 hasher.update(chunk)
16         return hasher.hexdigest()

靜態文件緩存源碼

二、csrf

Tornado中的跨站請求僞造和Django中的類似，跨站僞造請求(Cross-site request forgery)

1 settings = {
2     "xsrf_cookies": True,
3 }
4 application = tornado.web.Application([
5     (r"/", MainHandler),
6     (r"/login", LoginHandler),
7 ], **settings)

配置

1 # 普通表單使用
2 
3 <form action="/new_message" method="post">
4   {{ xsrf_form_html() }}
5   <input type="text" name="message"/>
6   <input type="submit" value="Post"/>
7 </form>

 1 # Ajax使用
 2 
 3 function getCookie(name) {
 4     var r = document.cookie.match("\\b" + name + "=([^;]*)\\b");
 5     return r ? r[1] : undefined;
 6 }
 7 
 8 jQuery.postJSON = function(url, args, callback) {
 9     args._xsrf = getCookie("_xsrf");
10     $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST",
11         success: function(response) {
12         callback(eval("(" + response + ")"));
13     }});
14 };

注：Ajax使用時，本質上就是去獲取本地的cookie，攜帶cookie再來發送請求

三、cookie

Tornado中能夠對cookie進行操做，而且還能夠對cookie進行簽名以放置僞造。

a、基本操做

1 class MainHandler(tornado.web.RequestHandler):
2     def get(self):
3         if not self.get_cookie("mycookie"):
4             self.set_cookie("mycookie", "myvalue")
5             self.write("Your cookie was not set yet!")
6         else:
7             self.write("Your cookie was set!")
8 
9 Code

b、簽名

Cookie 很容易被惡意的客戶端僞造。加入你想在 cookie 中保存當前登錄用戶的 id 之類的信息，你須要對 cookie 做簽名以防止僞造。Tornado 經過 set_secure_cookie 和 get_secure_cookie 方法直接支持了這種功能。要使用這些方法，你須要在建立應用時提供一個密鑰，名字爲 cookie_secret。你能夠把它做爲一個關鍵詞參數傳入應用的設置中：

 1 class MainHandler(tornado.web.RequestHandler):
 2     def get(self):
 3         if not self.get_secure_cookie("mycookie"):
 4             self.set_secure_cookie("mycookie", "myvalue")
 5             self.write("Your cookie was not set yet!")
 6         else:
 7             self.write("Your cookie was set!")
 8              
 9 application = tornado.web.Application([
10     (r"/", MainHandler),
11 ], cookie_secret="61oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=")

Code

 1 def _create_signature_v1(secret, *parts):
 2     hash = hmac.new(utf8(secret), digestmod=hashlib.sha1)
 3     for part in parts:
 4         hash.update(utf8(part))
 5     return utf8(hash.hexdigest())
 6 
 7 
 8 def _create_signature_v2(secret, s):
 9     hash = hmac.new(utf8(secret), digestmod=hashlib.sha256)
10     hash.update(utf8(s))
11     return utf8(hash.hexdigest())

內部算法

 1 def create_signed_value(secret, name, value, version=None, clock=None,
 2                         key_version=None):
 3     if version is None:
 4         version = DEFAULT_SIGNED_VALUE_VERSION
 5     if clock is None:
 6         clock = time.time
 7 
 8     timestamp = utf8(str(int(clock())))
 9     value = base64.b64encode(utf8(value))
10     if version == 1:
11         signature = _create_signature_v1(secret, name, value, timestamp)
12         value = b"|".join([value, timestamp, signature])
13         return value
14     elif version == 2:
15         # The v2 format consists of a version number and a series of
16         # length-prefixed fields "%d:%s", the last of which is a
17         # signature, all separated by pipes.  All numbers are in
18         # decimal format with no leading zeros.  The signature is an
19         # HMAC-SHA256 of the whole string up to that point, including
20         # the final pipe.
21         #
22         # The fields are:
23         # - format version (i.e. 2; no length prefix)
24         # - key version (integer, default is 0)
25         # - timestamp (integer seconds since epoch)
26         # - name (not encoded; assumed to be ~alphanumeric)
27         # - value (base64-encoded)
28         # - signature (hex-encoded; no length prefix)
29         def format_field(s):
30             return utf8("%d:" % len(s)) + utf8(s)
31         to_sign = b"|".join([
32             b"2",
33             format_field(str(key_version or 0)),
34             format_field(timestamp),
35             format_field(name),
36             format_field(value),
37             b''])
38 
39         if isinstance(secret, dict):
40             assert key_version is not None, 'Key version must be set when sign key dict is used'
41             assert version >= 2, 'Version must be at least 2 for key version support'
42             secret = secret[key_version]
43 
44         signature = _create_signature_v2(secret, to_sign)
45         return to_sign + signature
46     else:
47         raise ValueError("Unsupported version %d" % version)

內部算法-加密

 1 def _decode_signed_value_v1(secret, name, value, max_age_days, clock):
 2     parts = utf8(value).split(b"|")
 3     if len(parts) != 3:
 4         return None
 5     signature = _create_signature_v1(secret, name, parts[0], parts[1])
 6     if not _time_independent_equals(parts[2], signature):
 7         gen_log.warning("Invalid cookie signature %r", value)
 8         return None
 9     timestamp = int(parts[1])
10     if timestamp < clock() - max_age_days * 86400:
11         gen_log.warning("Expired cookie %r", value)
12         return None
13     if timestamp > clock() + 31 * 86400:
14         # _cookie_signature does not hash a delimiter between the
15         # parts of the cookie, so an attacker could transfer trailing
16         # digits from the payload to the timestamp without altering the
17         # signature.  For backwards compatibility, sanity-check timestamp
18         # here instead of modifying _cookie_signature.
19         gen_log.warning("Cookie timestamp in future; possible tampering %r",
20                         value)
21         return None
22     if parts[1].startswith(b"0"):
23         gen_log.warning("Tampered cookie %r", value)
24         return None
25     try:
26         return base64.b64decode(parts[0])
27     except Exception:
28         return None
29 
30 
31 def _decode_fields_v2(value):
32     def _consume_field(s):
33         length, _, rest = s.partition(b':')
34         n = int(length)
35         field_value = rest[:n]
36         # In python 3, indexing bytes returns small integers; we must
37         # use a slice to get a byte string as in python 2.
38         if rest[n:n + 1] != b'|':
39             raise ValueError("malformed v2 signed value field")
40         rest = rest[n + 1:]
41         return field_value, rest
42 
43     rest = value[2:]  # remove version number
44     key_version, rest = _consume_field(rest)
45     timestamp, rest = _consume_field(rest)
46     name_field, rest = _consume_field(rest)
47     value_field, passed_sig = _consume_field(rest)
48     return int(key_version), timestamp, name_field, value_field, passed_sig
49 
50 
51 def _decode_signed_value_v2(secret, name, value, max_age_days, clock):
52     try:
53         key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value)
54     except ValueError:
55         return None
56     signed_string = value[:-len(passed_sig)]
57 
58     if isinstance(secret, dict):
59         try:
60             secret = secret[key_version]
61         except KeyError:
62             return None
63 
64     expected_sig = _create_signature_v2(secret, signed_string)
65     if not _time_independent_equals(passed_sig, expected_sig):
66         return None
67     if name_field != utf8(name):
68         return None
69     timestamp = int(timestamp)
70     if timestamp < clock() - max_age_days * 86400:
71         # The signature has expired.
72         return None
73     try:
74         return base64.b64decode(value_field)
75     except Exception:
76         return None
77 
78 
79 def get_signature_key_version(value):
80     value = utf8(value)
81     version = _get_version(value)
82     if version < 2:
83         return None
84     try:
85         key_version, _, _, _, _ = _decode_fields_v2(value)
86     except ValueError:
87         return None
88 
89     return key_version

內部算法-解密

簽名Cookie的本質是：

寫cookie過程：

將值進行base64加密

對除值之外的內容進行簽名，哈希算法（沒法逆向解析）

拼接簽名 + 加密值

讀cookie過程：

讀取簽名 + 加密值

對簽名進行驗證

base64解密，獲取值內容

注：許多API驗證機制和安全cookie的實現機制相同。

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7  
 8 class MainHandler(tornado.web.RequestHandler):
 9  
10     def get(self):
11         login_user = self.get_secure_cookie("login_user", None)
12         if login_user:
13             self.write(login_user)
14         else:
15             self.redirect('/login')
16  
17  
18 class LoginHandler(tornado.web.RequestHandler):
19     def get(self):
20         self.current_user()
21  
22         self.render('login.html', **{'status': ''})
23  
24     def post(self, *args, **kwargs):
25  
26         username = self.get_argument('name')
27         password = self.get_argument('pwd')
28         if username == 'wupeiqi' and password == '123':
29             self.set_secure_cookie('login_user', '武沛齊')
30             self.redirect('/')
31         else:
32             self.render('login.html', **{'status': '用戶名或密碼錯誤'})
33  
34 settings = {
35     'template_path': 'template',
36     'static_path': 'static',
37     'static_url_prefix': '/static/',
38     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh'
39 }
40  
41 application = tornado.web.Application([
42     (r"/index", MainHandler),
43     (r"/login", LoginHandler),
44 ], **settings)
45  
46  
47 if __name__ == "__main__":
48     application.listen(8888)
49     tornado.ioloop.IOLoop.instance().start()

Demo-基於cookie進行用戶驗證

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3  
 4 import tornado.ioloop
 5 import tornado.web
 6  
 7 class BaseHandler(tornado.web.RequestHandler):
 8  
 9     def get_current_user(self):
10         return self.get_secure_cookie("login_user")
11  
12 class MainHandler(BaseHandler):
13  
14     @tornado.web.authenticated
15     def get(self):
16         login_user = self.current_user
17         self.write(login_user)
18  
19  
20  
21 class LoginHandler(tornado.web.RequestHandler):
22     def get(self):
23         self.current_user()
24  
25         self.render('login.html', **{'status': ''})
26  
27     def post(self, *args, **kwargs):
28  
29         username = self.get_argument('name')
30         password = self.get_argument('pwd')
31         if username == 'wupeiqi' and password == '123':
32             self.set_secure_cookie('login_user', '武沛齊')
33             self.redirect('/')
34         else:
35             self.render('login.html', **{'status': '用戶名或密碼錯誤'})
36  
37 settings = {
38     'template_path': 'template',
39     'static_path': 'static',
40     'static_url_prefix': '/static/',
41     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
42     'login_url': '/login'
43 }
44  
45 application = tornado.web.Application([
46     (r"/index", MainHandler),
47     (r"/login", LoginHandler),
48 ], **settings)
49  
50  
51 if __name__ == "__main__":
52     application.listen(8888)
53     tornado.ioloop.IOLoop.instance().start()

Demo-Toando內部提供基於cookie進行用戶驗證

5、擴展功能

一、自定義Session

a.知識儲備

 
         #!/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實現機制

 1 import tornado.ioloop
 2 import tornado.web
 3 from hashlib import sha1
 4 import os, time
 5   
 6 session_container = {}
 7   
 8 create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()
 9   
10   
11 class Session(object):
12   
13     session_id = "__sessionId__"
14   
15     def __init__(self, request):
16         session_value = request.get_cookie(Session.session_id)
17         if not session_value:
18             self._id = create_session_id()
19         else:
20             self._id = session_value
21         request.set_cookie(Session.session_id, self._id)
22   
23     def __getitem__(self, key):
24         return session_container[self._id][key]
25   
26     def __setitem__(self, key, value):
27         if session_container.has_key(self._id):
28             session_container[self._id][key] = value
29         else:
30             session_container[self._id] = {key: value}
31   
32     def __delitem__(self, key):
33         del session_container[self._id][key]
34   
35   
36 class BaseHandler(tornado.web.RequestHandler):
37   
38     def initialize(self):
39         # my_session['k1']訪問 __getitem__ 方法
40         self.my_session = Session(self)
41   
42   
43 class MainHandler(BaseHandler):
44   
45     def get(self):
46         print self.my_session['c_user']
47         print self.my_session['c_card']
48         self.write('index')
49   
50 class LoginHandler(BaseHandler):
51   
52     def get(self):
53         self.render('login.html', **{'status': ''})
54   
55     def post(self, *args, **kwargs):
56   
57         username = self.get_argument('name')
58         password = self.get_argument('pwd')
59         if username == 'wupeiqi' and password == '123':
60   
61             self.my_session['c_user'] = 'wupeiqi'
62             self.my_session['c_card'] = '12312312309823012'
63   
64             self.redirect('/index')
65         else:
66             self.render('login.html', **{'status': '用戶名或密碼錯誤'})
67   
68 settings = {
69     'template_path': 'template',
70     'static_path': 'static',
71     'static_url_prefix': '/static/',
72     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
73     'login_url': '/login'
74 }
75   
76 application = tornado.web.Application([
77     (r"/index", MainHandler),
78     (r"/login", LoginHandler),
79 ], **settings)
80   
81   
82 if __name__ == "__main__":
83     application.listen(8888)
84     tornado.ioloop.IOLoop.instance().start()

View Code

c. Session框架

  1 #!/usr/bin/env python
  2 #coding:utf-8
  3 
  4 import sys
  5 import math
  6 from bisect import bisect
  7 
  8 
  9 if sys.version_info >= (2, 5):
 10     import hashlib
 11     md5_constructor = hashlib.md5
 12 else:
 13     import md5
 14     md5_constructor = md5.new
 15 
 16 
 17 class HashRing(object):
 18     """一致性哈希"""
 19     
 20     def __init__(self,nodes):
 21         '''初始化
 22         nodes : 初始化的節點，其中包含節點已經節點對應的權重
 23                 默認每個節點有32個虛擬節點
 24                 對於權重，經過多建立虛擬節點來實現
 25                 如：nodes = [
 26                         {'host':'127.0.0.1:8000','weight':1},
 27                         {'host':'127.0.0.1:8001','weight':2},
 28                         {'host':'127.0.0.1:8002','weight':1},
 29                     ]
 30         '''
 31         
 32         self.ring = dict()
 33         self._sorted_keys = []
 34 
 35         self.total_weight = 0
 36         
 37         self.__generate_circle(nodes)
 38         
 39             
 40             
 41     def __generate_circle(self,nodes):
 42         for node_info in nodes:
 43             self.total_weight += node_info.get('weight',1)
 44             
 45         for node_info in nodes:
 46             weight = node_info.get('weight',1)
 47             node = node_info.get('host',None)
 48                 
 49             virtual_node_count = math.floor((32*len(nodes)*weight) / self.total_weight)
 50             for i in xrange(0,int(virtual_node_count)):
 51                 key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
 52                 if self._sorted_keys.__contains__(key):
 53                     raise Exception('該節點已經存在.')
 54                 self.ring[key] = node
 55                 self._sorted_keys.append(key)
 56             
 57     def add_node(self,node):
 58         ''' 新建節點
 59         node : 要添加的節點，格式爲：{'host':'127.0.0.1:8002','weight':1}，其中第一個元素表示節點，第二個元素表示該節點的權重。
 60         '''
 61         node = node.get('host',None)
 62         if not node:
 63                 raise Exception('節點的地址不能爲空.')
 64                 
 65         weight = node.get('weight',1)
 66         
 67         self.total_weight += weight
 68         nodes_count = len(self._sorted_keys) + 1
 69         
 70         virtual_node_count = math.floor((32 * nodes_count * weight) / self.total_weight)
 71         for i in xrange(0,int(virtual_node_count)):
 72             key = self.gen_key_thirty_two( '%s-%s' % (node, i) )
 73             if self._sorted_keys.__contains__(key):
 74                 raise Exception('該節點已經存在.')
 75             self.ring[key] = node
 76             self._sorted_keys.append(key)
 77         
 78     def remove_node(self,node):
 79         ''' 移除節點
 80         node : 要移除的節點 '127.0.0.1:8000'
 81         '''
 82         for key,value in self.ring.items():
 83             if value == node:
 84                 del self.ring[key]
 85                 self._sorted_keys.remove(key)
 86     
 87     def get_node(self,string_key):
 88         '''獲取 string_key 所在的節點'''
 89         pos = self.get_node_pos(string_key)
 90         if pos is None:
 91             return None
 92         return self.ring[ self._sorted_keys[pos]].split(':')
 93     
 94     def get_node_pos(self,string_key):
 95         '''獲取 string_key 所在的節點的索引'''
 96         if not self.ring:
 97             return None
 98             
 99         key = self.gen_key_thirty_two(string_key)
100         nodes = self._sorted_keys
101         pos = bisect(nodes, key)
102         return pos
103     
104     def gen_key_thirty_two(self, key):
105         
106         m = md5_constructor()
107         m.update(key)
108         return long(m.hexdigest(), 16)
109         
110     def gen_key_sixteen(self,key):
111         
112         b_key = self.__hash_digest(key)
113         return self.__hash_val(b_key, lambda x: x)
114 
115     def __hash_val(self, b_key, entry_fn):
116         return (( b_key[entry_fn(3)] << 24)|(b_key[entry_fn(2)] << 16)|(b_key[entry_fn(1)] << 8)| b_key[entry_fn(0)] )
117 
118     def __hash_digest(self, key):
119         m = md5_constructor()
120         m.update(key)
121         return map(ord, m.digest())
122 
123 
124 """
125 nodes = [
126     {'host':'127.0.0.1:8000','weight':1},
127     {'host':'127.0.0.1:8001','weight':2},
128     {'host':'127.0.0.1:8002','weight':1},
129 ]
130 
131 ring = HashRing(nodes)
132 result = ring.get_node('98708798709870987098709879087')
133 print result
134 
135 """

一致性哈希

 1 from hashlib import sha1
 2 import os, time
 3 
 4 
 5 create_session_id = lambda: sha1('%s%s' % (os.urandom(16), time.time())).hexdigest()
 6 
 7 
 8 class Session(object):
 9 
10     session_id = "__sessionId__"
11 
12     def __init__(self, request):
13         session_value = request.get_cookie(Session.session_id)
14         if not session_value:
15             self._id = create_session_id()
16         else:
17             self._id = session_value
18         request.set_cookie(Session.session_id, self._id)
19 
20     def __getitem__(self, key):
21         # 根據 self._id ，在一致性哈西中找到其對應的服務器IP
22         # 找到相對應的redis服務器，如： r = redis.StrictRedis(host='localhost', port=6379, db=0)
23         # 使用python redis api 連接
24         # 獲取數據，即：
25         # return self._redis.hget(self._id, name)
26 
27     def __setitem__(self, key, value):
28         # 根據 self._id ，在一致性哈西中找到其對應的服務器IP
29         # 使用python redis api 連接
30         # 設置session
31         # self._redis.hset(self._id, name, value)
32 
33 
34     def __delitem__(self, key):
35         # 根據 self._id 找到相對應的redis服務器
36         # 使用python redis api 連接
37         # 刪除，即：
38         return self._redis.hdel(self._id, name)
39

Session

二、自定義模型版定

模型綁定有兩個主要功能：

自動生成html表單
用戶輸入驗證

在以前學習的Django中爲程序員提供了很是便捷的模型綁定功能，可是在Tornado中，一切須要本身動手！！！

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <link href="{{static_url("commons.css")}}" rel="stylesheet" />
 7 </head>
 8 <body>
 9     <h1>hello</h1>
10     <form action="/index" method="post">
11 
12         <p>hostname: <input type="text" name="host" /> </p>
13         <p>ip: <input type="text" name="ip" /> </p>
14         <p>port: <input type="text" name="port" /> </p>
15         <p>phone: <input type="text" name="phone" /> </p>
16         <input type="submit" />
17     </form>
18 </body>
19 </html>

 1 import tornado.ioloop
 2 import tornado.web
 3 from hashlib import sha1
 4 import os, time
 5 import re
 6   
 7   
 8 class MainForm(object):
 9     def __init__(self):
10         self.host = "(.*)"
11         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}$"
12         self.port = '(\d+)'
13         self.phone = '^1[3|4|5|8][0-9]\d{8}$'
14   
15     def check_valid(self, request):
16         form_dict = self.__dict__
17         for key, regular in form_dict.items():
18             post_value = request.get_argument(key)
19             # 讓提交的數據 和 定義的正則表達式進行匹配
20             ret = re.match(regular, post_value)
21             print key,ret,post_value
22   
23   
24 class MainHandler(tornado.web.RequestHandler):
25     def get(self):
26         self.render('index.html')
27     def post(self, *args, **kwargs):
28         obj = MainForm()
29         result = obj.check_valid(self)
30         self.write('ok')
31   
32   
33   
34 settings = {
35     'template_path': 'template',
36     'static_path': 'static',
37     'static_url_prefix': '/static/',
38     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
39     'login_url': '/login'
40 }
41   
42 application = tornado.web.Application([
43     (r"/index", MainHandler),
44 ], **settings)
45   
46   
47 if __name__ == "__main__":
48     application.listen(8888)
49     tornado.ioloop.IOLoop.instance().start()

因爲請求的驗證時，須要考慮是否能夠爲空以及正則表達式的複用，因此：

  1 # Form驗證框架
  2 
  3 import tornado.ioloop
  4 import tornado.web
  5 import re
  6 
  7 
  8 class Field(object):
  9 
 10     def __init__(self, error_msg_dict, required):
 11         self.id_valid = False
 12         self.value = None
 13         self.error = None
 14         self.name = None
 15         self.error_msg = error_msg_dict
 16         self.required = required
 17 
 18     def match(self, name, value):
 19         self.name = name
 20 
 21         if not self.required:
 22             self.id_valid = True
 23             self.value = value
 24         else:
 25             if not value:
 26                 if self.error_msg.get('required', None):
 27                     self.error = self.error_msg['required']
 28                 else:
 29                     self.error = "%s is required" % name
 30             else:
 31                 ret = re.match(self.REGULAR, value)
 32                 if ret:
 33                     self.id_valid = True
 34                     self.value = ret.group()
 35                 else:
 36                     if self.error_msg.get('valid', None):
 37                         self.error = self.error_msg['valid']
 38                     else:
 39                         self.error = "%s is invalid" % name
 40 
 41 
 42 class IPField(Field):
 43     REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$"
 44 
 45     def __init__(self, error_msg_dict=None, required=True):
 46 
 47         error_msg = {}  # {'required': 'IP不能爲空', 'valid': 'IP格式錯誤'}
 48         if error_msg_dict:
 49             error_msg.update(error_msg_dict)
 50 
 51         super(IPField, self).__init__(error_msg_dict=error_msg, required=required)
 52 
 53 
 54 class IntegerField(Field):
 55     REGULAR = "^\d+$"
 56 
 57     def __init__(self, error_msg_dict=None, required=True):
 58         error_msg = {'required': '數字不能爲空', 'valid': '數字格式錯誤'}
 59         if error_msg_dict:
 60             error_msg.update(error_msg_dict)
 61 
 62         super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required)
 63 
 64 
 65 class CheckBoxField(Field):
 66 
 67     def __init__(self, error_msg_dict=None, required=True):
 68         error_msg = {}  # {'required': 'IP不能爲空', 'valid': 'IP格式錯誤'}
 69         if error_msg_dict:
 70             error_msg.update(error_msg_dict)
 71 
 72         super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required)
 73 
 74     def match(self, name, value):
 75         self.name = name
 76 
 77         if not self.required:
 78             self.id_valid = True
 79             self.value = value
 80         else:
 81             if not value:
 82                 if self.error_msg.get('required', None):
 83                     self.error = self.error_msg['required']
 84                 else:
 85                     self.error = "%s is required" % name
 86             else:
 87                 if isinstance(name, list):
 88                     self.id_valid = True
 89                     self.value = value
 90                 else:
 91                     if self.error_msg.get('valid', None):
 92                         self.error = self.error_msg['valid']
 93                     else:
 94                         self.error = "%s is invalid" % name
 95 
 96 
 97 class FileField(Field):
 98     REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$"
 99 
100     def __init__(self, error_msg_dict=None, required=True):
101         error_msg = {}  # {'required': '數字不能爲空', 'valid': '數字格式錯誤'}
102         if error_msg_dict:
103             error_msg.update(error_msg_dict)
104 
105         super(FileField, self).__init__(error_msg_dict=error_msg, required=required)
106 
107     def match(self, name, value):
108         self.name = name
109         self.value = []
110         if not self.required:
111             self.id_valid = True
112             self.value = value
113         else:
114             if not value:
115                 if self.error_msg.get('required', None):
116                     self.error = self.error_msg['required']
117                 else:
118                     self.error = "%s is required" % name
119             else:
120                 m = re.compile(self.REGULAR)
121                 if isinstance(value, list):
122                     for file_name in value:
123                         r = m.match(file_name)
124                         if r:
125                             self.value.append(r.group())
126                             self.id_valid = True
127                         else:
128                             self.id_valid = False
129                             if self.error_msg.get('valid', None):
130                                 self.error = self.error_msg['valid']
131                             else:
132                                 self.error = "%s is invalid" % name
133                             break
134                 else:
135                     if self.error_msg.get('valid', None):
136                         self.error = self.error_msg['valid']
137                     else:
138                         self.error = "%s is invalid" % name
139 
140     def save(self, request, upload_path=""):
141 
142         file_metas = request.files[self.name]
143         for meta in file_metas:
144             file_name = meta['filename']
145             with open(file_name,'wb') as up:
146                 up.write(meta['body'])
147 
148 
149 class Form(object):
150 
151     def __init__(self):
152         self.value_dict = {}
153         self.error_dict = {}
154         self.valid_status = True
155 
156     def validate(self, request, depth=10, pre_key=""):
157 
158         self.initialize()
159         self.__valid(self, request, depth, pre_key)
160 
161     def initialize(self):
162         pass
163 
164     def __valid(self, form_obj, request, depth, pre_key):
165         """
166         驗證用戶表單請求的數據
167         :param form_obj: Form對象（Form派生類的對象）
168         :param request: Http請求上下文（用於從請求中獲取用戶提交的值）
169         :param depth: 對Form內容的深度的支持
170         :param pre_key: Html中name屬性值的前綴（多層Form時，內部遞歸時設置，無需理會）
171         :return: 是否驗證經過，True：驗證成功；False：驗證失敗
172         """
173 
174         depth -= 1
175         if depth < 0:
176             return None
177         form_field_dict = form_obj.__dict__
178         for key, field_obj in form_field_dict.items():
179             print key,field_obj
180             if isinstance(field_obj, Form) or isinstance(field_obj, Field):
181                 if isinstance(field_obj, Form):
182                     # 獲取以key開頭的全部的值，以參數的形式傳至
183                     self.__valid(field_obj, request, depth, key)
184                     continue
185                 if pre_key:
186                     key = "%s.%s" % (pre_key, key)
187 
188                 if isinstance(field_obj, CheckBoxField):
189                     post_value = request.get_arguments(key, None)
190                 elif isinstance(field_obj, FileField):
191                     post_value = []
192                     file_list = request.request.files.get(key, None)
193                     for file_item in file_list:
194                         post_value.append(file_item['filename'])
195                 else:
196                     post_value = request.get_argument(key, None)
197 
198                 print post_value
199                 # 讓提交的數據 和 定義的正則表達式進行匹配
200                 field_obj.match(key, post_value)
201                 if field_obj.id_valid:
202                     self.value_dict[key] = field_obj.value
203                 else:
204                     self.error_dict[key] = field_obj.error
205                     self.valid_status = False
206 
207 
208 class ListForm(object):
209     def __init__(self, form_type):
210         self.form_type = form_type
211         self.valid_status = True
212         self.value_dict = {}
213         self.error_dict = {}
214 
215     def validate(self, request):
216         name_list = request.request.arguments.keys() + request.request.files.keys()
217         index = 0
218         flag = False
219         while True:
220             pre_key = "[%d]" % index
221             for name in name_list:
222                 if name.startswith(pre_key):
223                     flag = True
224                     break
225             if flag:
226                 form_obj = self.form_type()
227                 form_obj.validate(request, depth=10, pre_key="[%d]" % index)
228                 if form_obj.valid_status:
229                     self.value_dict[index] = form_obj.value_dict
230                 else:
231                     self.error_dict[index] = form_obj.error_dict
232                     self.valid_status = False
233             else:
234                 break
235 
236             index += 1
237             flag = False
238 
239 
240 class MainForm(Form):
241 
242     def __init__(self):
243         # self.ip = IPField(required=True)
244         # self.port = IntegerField(required=True)
245         # self.new_ip = IPField(required=True)
246         # self.second = SecondForm()
247         self.fff = FileField(required=True)
248         super(MainForm, self).__init__()
249 
250 #
251 # class SecondForm(Form):
252 #
253 #     def __init__(self):
254 #         self.ip = IPField(required=True)
255 #         self.new_ip = IPField(required=True)
256 #
257 #         super(SecondForm, self).__init__()
258 
259 
260 class MainHandler(tornado.web.RequestHandler):
261     def get(self):
262         self.render('index.html')
263     def post(self, *args, **kwargs):
264         # for i in  dir(self.request):
265         #     print i
266         # print self.request.arguments
267         # print self.request.files
268         # print self.request.query
269         # name_list = self.request.arguments.keys() + self.request.files.keys()
270         # print name_list
271 
272         # list_form = ListForm(MainForm)
273         # list_form.validate(self)
274         #
275         # print list_form.valid_status
276         # print list_form.value_dict
277         # print list_form.error_dict
278 
279         # obj = MainForm()
280         # obj.validate(self)
281         #
282         # print "驗證結果：", obj.valid_status
283         # print "符合驗證結果：", obj.value_dict
284         # print "錯誤信息:"
285         # for key, item in obj.error_dict.items():
286         #     print key,item
287         # print self.get_arguments('favor'),type(self.get_arguments('favor'))
288         # print self.get_argument('favor'),type(self.get_argument('favor'))
289         # print type(self.get_argument('fff')),self.get_argument('fff')
290         # print self.request.files
291         # obj = MainForm()
292         # obj.validate(self)
293         # print obj.valid_status
294         # print obj.value_dict
295         # print obj.error_dict
296         # print self.request,type(self.request)
297         # obj.fff.save(self.request)
298         # from tornado.httputil import HTTPServerRequest
299         # name_list = self.request.arguments.keys() + self.request.files.keys()
300         # print name_list
301         # print self.request.files,type(self.request.files)
302         # print len(self.request.files.get('fff'))
303         
304         # obj = MainForm()
305         # obj.validate(self)
306         # print obj.valid_status
307         # print obj.value_dict
308         # print obj.error_dict
309         # obj.fff.save(self.request)
310         self.write('ok')
311 
312 
313 
314 settings = {
315     'template_path': 'template',
316     'static_path': 'static',
317     'static_url_prefix': '/static/',
318     'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh',
319     'login_url': '/login'
320 }
321 
322 application = tornado.web.Application([
323     (r"/index", MainHandler),
324 ], **settings)
325 
326 
327 if __name__ == "__main__":
328     application.listen(8888)
329     tornado.ioloop.IOLoop.instance().start()