概述 Tornado 是 FriendFeed 使用的可擴展的非阻塞式 web 伺服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,不過為了能有效利用非阻塞式伺服器環境,這個 Web 框架還包含了一些相關的有用工具 和優化。 Tornado ...
概述
Tornado 是 FriendFeed 使用的可擴展的非阻塞式 web 伺服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,不過為了能有效利用非阻塞式伺服器環境,這個 Web 框架還包含了一些相關的有用工具 和優化。
Tornado 和現在的主流 Web 伺服器框架(包括大多數 Python 的框架)有著明顯的區別:它是非阻塞式伺服器,而且速度相當快。得利於其 非阻塞的方式和對 epoll 的運用,Tornado 每秒可以處理數以千計的連接,這意味著對於實時 Web 服務來說,Tornado 是一個理想的 Web 框架。我們開發這個 Web 伺服器的主要目的就是為了處理 FriendFeed 的實時功能 ——在 FriendFeed 的應用里每一個活動用戶都會保持著一個伺服器連接。(關於如何擴容 伺服器,以處理數以千計的客戶端的連接的問題,請參閱 C10K problem。)
下載安裝:
pip3 install tornado 源碼安裝 https://pypi.python.org/packages/source/t/tornado/tornado-4.3.tar.gz
框架使用
一、快速上手
#!/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()
執行過程:
- 第一步:執行腳本,監聽 8888 埠
- 第二步:瀏覽器客戶端訪問 /index --> http://127.0.0.1:8888/index
- 第三步:伺服器接受請求,並交由對應的類處理該請求
- 第四步:類接受到請求之後,根據請求方式(post / get / delete ...)的不同調用並執行相應的方法
- 第五步:方法返回值的字元串內容發送瀏覽器
#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web from tornado import httpclient from tornado.web import asynchronous from tornado import gen import uimodules as md import uimethods as mt class 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.body 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() 非同步非阻塞示例非同步非阻塞示例
二、路由系統
路由系統其實就是 url 和 類 的對應關係,這裡不同於其他框架,其他很多框架均是 url 對應 函數,Tornado中每個url對應的是一個類。
#!/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()
Tornado中原生支持二級功能變數名稱的路由,如:
三、模板引擎
Tornao中的模板語言和django中類似,模板引擎將模板文件載入記憶體,然後將數據嵌入其中,最終獲取到一個完整的字元串,再將字元串返回給請求者。
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 語句的格式基本完全相同。我們支持 if
、for
、while
和 try
,這些語句邏輯結束的位置需要用 {% end %}
做標記。還通過 extends
和 block
語句實現了模板繼承。這些在 template
模塊 的代碼文檔中有著詳細的描述。
註:在使用模板前需要在setting中設置模板路徑:"template_path" : "tpl"
1、基本使用
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web class MainHandler(tornado.web.RequestHandler): def get(self): self.render("index.html", list_info = [11,22,33]) application = tornado.web.Application([ (r"/index", MainHandler), ]) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start() app.pyapp.py
<!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" /> </head> <body> <div> <ul> {% for item in list_info %} <li>{{item}}</li> {% end %} </ul> </div> <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> </body> </html> index.htmlindex.html
在模板中預設提供了一些函數、欄位、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 其他方法其他方法
2、母版
<!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.htmllayout.html
{% 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.htmlindex.html
3、導入
<div>
<ul>
<li>1024</li>
<li>42區</li>
</ul>
</div>
header.html
header.html
<!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" /> </head> <body> <div class="pg-header"> {% include 'header.html' %} </div> <script src="{{static_url("js/jquery-1.8.2.min.js")}}"></script> </body> </html> index.htmlindex.html
4、自定義UIMethod以UIModule
a. 定義
# uimethods.py def tab(self): return 'UIMethod'uimethods.py
#!/usr/bin/env python # -*- coding:utf-8 -*- from tornado.web import UIModule from tornado import escape class custom(UIModule): def render(self, *args, **kwargs): return escape.xhtml_escape('<h1>wupeiqi</h1>') #return escape.xhtml_escape('<h1>wupeiqi</h1>') uimodules.pyuimodules.py
b. 註冊
#!/usr/bin/env python # -*- coding:utf-8 -*- #!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import tornado.web from tornado.escape import linkify import uimodules as md import uimethods as mt class 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()View Code
c. 使用
<!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>View Code
四、靜態文件
對於靜態文件,可以配置靜態文件的目錄和前段使用時的首碼,並且Tornaodo還支持靜態文件緩存。
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import 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() app.pyapp.py
<!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.htmlindex.html
註:靜態文件緩存的實現
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()View Code
五、cookie
Tornado中可以對cookie進行操作,並且還可以對cookie進行簽名以放置偽造。
1、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!")
2、加密cookie(簽名)
Cookie 很容易被惡意的客戶端偽造。加入你想在 cookie 中保存當前登陸用戶的 id 之類的信息,你需要對 cookie 作簽名以防止偽造。Tornado 通過 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,你需要在創建應用時提供一個密鑰,名字為 cookie_secret。 你可以把它作為一個關鍵詞參數傳入應用的設置中:
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=")
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()) # 加密 def _create_signature_v2(secret, s): hash = hmac.new(utf8(secret), digestmod=hashlib.sha256) hash.update(utf8(s)) return utf8(hash.hexdigest()) 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 = base64.b64encode(utf8(value)) if version == 1: signature = _create_signature_v1(secret, name, value, timestamp) value = b"|".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) # 解密 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 None def _decode_fields_v2(value): def _consume_field(s): length, _, rest = s.partition(b':') n = int(length) field_value = rest[:n] # In python 3, indexing bytes returns small integers; we must # use a slice to get a byte string as in python 2. if rest[n:n + 1] != b'|': raise ValueError("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_sig def _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 None def 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 內部演算法內部演算法
簽名Cookie的本質是:
寫cookie過程:
- 將值進行base64加密
- 對除值以外的內容進行簽名,哈希演算法(無法逆向解析)
- 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
註:許多API驗證機制和安全cookie的實現機制相同。
#!/usr/bin/env python # -*- coding:utf-8 -*- import tornado.ioloop import 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', '武沛齊') self.redirect('/') else: self.render('login.html', **{'status': '用戶名或密碼錯誤'}) settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'cookie_secret':