Tornado初探
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。）
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pip install tornado源码安装 https://pypi.python.org/packages/source/t/tornado/tornado-4.3.tar.gz |
一、快速上手
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#!/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
#!/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()
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。
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#!/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 if、for、while 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。
<!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>
{% 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 %}
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#!/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：
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模组handler: 当前的RequestHandler对象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: forhandler.static_url的別名xsrf_form_html:handler.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
# uimethods.py def tab(self):
return 'UIMethod'
#!/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>')
2、注册
#!/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()
3、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>
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。
#!/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()
<!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>
备注：静态文件缓存的实现
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()
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)
settings = {
"xsrf_cookies": True,
}
application = tornado.web.Application([
(r"/", MainHandler),
(r"/login", LoginHandler),
], **settings)
<form action="/new_message" method="post">
{{ xsrf_form_html() }}
<input type="text" name="message"/>
<input type="submit" value="Post"/>
</form>
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 + ")"));
}});
};
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：
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()) 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)
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
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。
#!/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()
#!/usr/bin/env python
# -*- coding:utf-8 -*- import tornado.ioloop
import 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()
4、Ajax上传文件
<!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>
#!/usr/bin/env python
# -*- coding:utf-8 -*-
#!/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') 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()
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);
}
})
五、扩展功能
1、自定义Session
a.知识储备
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#!/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
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#!/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() |
c. Session框架
#!/usr/bin/env python
#coding:utf-8 import sys
import math
from bisect import bisect if sys.version_info >= (2, 5):
import hashlib
md5_constructor = hashlib.md5
else:
import md5
md5_constructor = md5.new class HashRing(object):
"""一致性哈希""" def __init__(self,nodes):
'''初始化
nodes : 初始化的节点，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 == 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 """
from hashlib import sha1
import os, time 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):
# 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)
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！！！
<!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>
<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>
|
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#!/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}$' def check_valid(self, request): form_dict = self.__dict__ for key, regular in form_dict.items(): post_value = request.get_argument(key) # 让提交的数据 和 定义的正则表达式进行匹配 ret = re.match(regular, post_value) print key,ret,post_value class MainHandler(tornado.web.RequestHandler): def get(self): self.render('index.html') def post(self, *args, **kwargs): obj = MainForm() result = obj.check_valid(self) self.write('ok') settings = { 'template_path': 'template', 'static_path': 'static', 'static_url_prefix': '/static/', 'cookie_secret': 'aiuasdhflashjdfoiuashdfiuh', 'login_url': '/login'} application = tornado.web.Application([ (r"/index", MainHandler),], **settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start() |
由于请求的验证时，需要考虑是否可以为空以及正则表达式的复用，所以：
#!/usr/bin/env python
# -*- coding:utf-8 -*- import tornado.ioloop
import tornado.web
import re class Field(object): def __init__(self, error_msg_dict, required):
self.id_valid = False
self.value = None
self.error = None
self.name = None
self.error_msg = error_msg_dict
self.required = required def match(self, name, value):
self.name = name if not self.required:
self.id_valid = True
self.value = value
else:
if not value:
if self.error_msg.get('required', None):
self.error = self.error_msg['required']
else:
self.error = "%s is required" % name
else:
ret = re.match(self.REGULAR, value)
if ret:
self.id_valid = True
self.value = ret.group()
else:
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name class IPField(Field):
REGULAR = "^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$" 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+$" def __init__(self, error_msg_dict=None, required=True):
error_msg = {'required': '数字不能为空', 'valid': '数字格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(IntegerField, self).__init__(error_msg_dict=error_msg, required=required) class CheckBoxField(Field): def __init__(self, error_msg_dict=None, required=True):
error_msg = {} # {'required': 'IP不能为空', 'valid': 'IP格式错误'}
if error_msg_dict:
error_msg.update(error_msg_dict) super(CheckBoxField, self).__init__(error_msg_dict=error_msg, required=required) def match(self, name, value):
self.name = name if not self.required:
self.id_valid = True
self.value = value
else:
if not value:
if self.error_msg.get('required', None):
self.error = self.error_msg['required']
else:
self.error = "%s is required" % name
else:
if isinstance(name, list):
self.id_valid = True
self.value = value
else:
if self.error_msg.get('valid', None):
self.error = self.error_msg['valid']
else:
self.error = "%s is invalid" % name class FileField(Field):
REGULAR = "^(\w+\.pdf)|(\w+\.mp3)|(\w+\.py)$" 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 = False class 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 = False class 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()
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