01 flask source code analysis of werkzurg understand wsgi

01 werkzurg understand wsgi

1. wsgi

django and internal flask did not realize socket, but wsgi achieve.
wsgi web services gateway interface, he is a protocol to implement its agreements are: wsgiref / werkzurg / uwsgi

1. Before django

   from wsgiref.simple_server import make_server
   
   def run(environ, start_response):
       start_response('200 OK', [('Content-Type', 'text/html')])
       return [bytes('<h1>Hello, web!</h1>', encoding='utf-8'), ]
   
   if __name__ == '__main__':
       httpd = make_server('127.0.0.1', 8000, run)
       httpd.serve_forever()

2. Before flask

   from werkzeug.serving import run_simple
   from werkzeug.wrappers import BaseResponse
   
   
   def func(environ, start_response):
       print('请求来了')
       response = BaseResponse('你好')
       return response(environ, start_response)
   
   
   if __name__ == '__main__':
       run_simple('127.0.0.1', 5000, func)

2. flask of werkzurg source process

1. Commencement of proceedingsapp.run()

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/index')
   def index():
       return 'hello world'
   
   if __name__ == '__main__':
       app.run()

2. Performed inside run_simplemethod bracketed third parameter

   def run(self, host=None, port=None, debug=None, load_dotenv=True, **options):
         from werkzeug.serving import run_simple
         run_simple(host, port, self, **options)

3. Trigger the execution __call__method, and then to perform the wsgi_appmethod

   def __call__(self, environ, start_response):
    return self.wsgi_app(environ, start_response)

4. Execution wsgi_appmethod inside the full_dispatch_requestmethod

   def wsgi_app(self, environ, start_response):
    response = self.full_dispatch_request()
    return response(environ, start_response)

   full_dispatch_request

   def full_dispatch_request(self):
       return self.finalize_request(rv)

5. Performing finalize_requestthe method, carrying rv parameter, the return value is a view rv

   def finalize_request(self, rv, from_error_handler=False):
       response = self.make_response(rv)
       return response

6. Execution finalize_requestmethod inside the make_responsemethod

   def make_response(self, rv):
    if not isinstance(rv, self.response_class):
            if isinstance(rv, (text_type, bytes, bytearray)):
                rv = self.response_class(rv, status=status, headers=headers)
                return rv

7. response_class

   • response_class=Response
   • ResponseThe inheritance werkzurgBaseResponse

3. Summary

• Request came after a series, and finally returned by BaseResponse

from werkzeug.serving import run_simple
from werkzeug.wrappers import BaseResponse

def func(environ, start_response):
    print('请求来了')
    response = BaseResponse('你好')
    return response(environ, start_response)


if __name__ == '__main__':
    run_simple('127.0.0.1', 5000, func)