自訂python非同步非阻塞Web架構執行個體代碼

本篇將使用200行程式碼完成一個微型非同步非阻塞Web架構：Snow。具有很好的參考價值，下面跟著小編一起來看下吧

Python的Web架構中Tornado以非同步非阻塞而聞名。本篇將使用200行程式碼完成一個微型非同步非阻塞Web架構：Snow。

一、源碼

本文基於非阻塞的Socket以及IO多工從而實現非同步非阻塞的Web架構，其中便是眾多非同步非阻塞Web架構內部原理。

#!/usr/bin/env python# -*- coding:utf-8 -*-import reimport socketimport selectimport timeclass HttpResponse(object): """ 封裝響應資訊 """ def init(self, content=''):  self.content = content  self.headers = {}  self.cookies = {} def response(self):  return bytes(self.content, encoding='utf-8')class HttpNotFound(HttpResponse): """ 404時的錯誤提示 """ def init(self):  super(HttpNotFound, self).init('404 Not Found')class HttpRequest(object): """ 使用者封裝使用者請求資訊 """ def init(self, conn):  self.conn = conn  self.header_bytes = bytes()  self.header_dict = {}  self.body_bytes = bytes()  self.method = ""  self.url = ""  self.protocol = ""  self.initialize()  self.initialize_headers() def initialize(self):  header_flag = False  while True:   try:    received = self.conn.recv(8096)   except Exception as e:    received = None   if not received:    break   if header_flag:    self.body_bytes += received    continue   temp = received.split(b'\r\n\r\n', 1)   if len(temp) == 1:    self.header_bytes += temp   else:    h, b = temp    self.header_bytes += h    self.body_bytes += b    header_flag = True @property def header_str(self):  return str(self.header_bytes, encoding='utf-8') def initialize_headers(self):  headers = self.header_str.split('\r\n')  first_line = headers[0].split(' ')  if len(first_line) == 3:   self.method, self.url, self.protocol = headers[0].split(' ')   for line in headers:    kv = line.split(':')    if len(kv) == 2:     k, v = kv     self.header_dict[k] = vclass Future(object): """ 非同步非阻塞模式時封裝回呼函數以及是否準備就緒 """ def init(self, callback):  self.callback = callback  self._ready = False  self.value = None def set_result(self, value=None):  self.value = value  self._ready = True @property def ready(self):  return self._readyclass TimeoutFuture(Future): """ 非同步非阻塞逾時 """ def init(self, timeout):  super(TimeoutFuture, self).init(callback=None)  self.timeout = timeout  self.start_time = time.time() @property def ready(self):  current_time = time.time()  if current_time > self.start_time + self.timeout:   self._ready = True  return self._readyclass Snow(object): """ 微型Web架構類 """ def init(self, routes):  self.routes = routes  self.inputs = set()  self.request = None  self.async_request_handler = {} def run(self, host='localhost', port=9999):  """  事件迴圈  :param host:  :param port:  :return:  """  sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  sock.bind((host, port,))  sock.setblocking(False)  sock.listen(128)  sock.setblocking(0)  self.inputs.add(sock)  try:   while True:    readable_list, writeable_list, error_list = select.select(self.inputs, [], self.inputs,0.005)    for conn in readable_list:     if sock == conn:      client, address = conn.accept()      client.setblocking(False)      self.inputs.add(client)     else:      gen = self.process(conn)      if isinstance(gen, HttpResponse):       conn.sendall(gen.response())       self.inputs.remove(conn)       conn.close()      else:       yielded = next(gen)self.async_request_handler[conn] = yielded    self.polling_callback()except Exception as e:   pass  finally:   sock.close()def polling_callback(self):  """  遍曆觸發非同步非阻塞的回呼函數  :return:  """  for conn in list(self.async_request_handler.keys()):   yielded = self.async_request_handler[conn]   if not yielded.ready:    continue   if yielded.callback:    ret = yielded.callback(self.request, yielded)    conn.sendall(ret.response())   self.inputs.remove(conn)   del self.async_request_handler[conn]   conn.close() def process(self, conn):  """  處理路由系統以及執行函數  :param conn:  :return:  """  self.request = HttpRequest(conn)  func = None  for route in self.routes:   if re.match(route[0], self.request.url):    func = route[1]    break  if not func:   return HttpNotFound()  else:   return func(self.request)snow.py

二、使用

1. 基本使用

from snow import Snowfrom snow import HttpResponsedef index(request):return HttpResponse('OK')routes = [ (r'/index/', index),]app = Snow(routes)app.run(port=8012)

2.非同步非阻塞：逾時

from snow import Snowfrom snow import HttpResponsefrom snow import TimeoutFuturerequest_list = []def async(request): obj = TimeoutFuture(5) yield objdef home(request): return HttpResponse('home')routes = [ (r'/home/', home), (r'/async/', async),]app = Snow(routes)app.run(port=8012)

3.非同步非阻塞：等待

基於等待模式可以完成自定製操作

from snow import Snowfrom snow import HttpResponsefrom snow import Futurerequest_list = []def callback(request, future): return HttpResponse(future.value)def req(request): obj = Future(callback=callback) request_list.append(obj) yield objdef stop(request): obj = request_list[0] del request_list[0] obj.set_result('done') return HttpResponse('stop')routes = [ (r'/req/', req), (r'/stop/', stop),]app = Snow(routes)app.run(port=8012)