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Package wsgiserver

source code

A high-speed, production ready, thread pooled, generic HTTP server.

Simplest example on how to use this module directly
(without using CherryPy's application machinery):

    from cherrypy import wsgiserver
    
    def my_crazy_app(environ, start_response):
        status = '200 OK'
        response_headers = [('Content-type','text/plain')]
        start_response(status, response_headers)
        return ['Hello world!
']
    
    server = wsgiserver.CherryPyWSGIServer(
                ('0.0.0.0', 8070), my_crazy_app,
                server_name='www.cherrypy.example')
    
The CherryPy WSGI server can serve as many WSGI applications 
as you want in one instance by using a WSGIPathInfoDispatcher:
    
    d = WSGIPathInfoDispatcher({'/': my_crazy_app, '/blog': my_blog_app})
    server = wsgiserver.CherryPyWSGIServer(('0.0.0.0', 80), d)
    
Want SSL support? Just set server.ssl_adapter to an SSLAdapter instance.

This won't call the CherryPy engine (application side) at all, only the
HTTP server, which is independent from the rest of CherryPy. Don't
let the name "CherryPyWSGIServer" throw you; the name merely reflects
its origin, not its coupling.

For those of you wanting to understand internals of this module, here's the
basic call flow. The server's listening thread runs a very tight loop,
sticking incoming connections onto a Queue:

    server = CherryPyWSGIServer(...)
    server.start()
    while True:
        tick()
        # This blocks until a request comes in:
        child = socket.accept()
        conn = HTTPConnection(child, ...)
        server.requests.put(conn)

Worker threads are kept in a pool and poll the Queue, popping off and then
handling each connection in turn. Each connection can consist of an arbitrary
number of requests and their responses, so we run a nested loop:

    while True:
        conn = server.requests.get()
        conn.communicate()
        ->  while True:
                req = HTTPRequest(...)
                req.parse_request()
                ->  # Read the Request-Line, e.g. "GET /page HTTP/1.1"
                    req.rfile.readline()
                    read_headers(req.rfile, req.inheaders)
                req.respond()
                ->  response = app(...)
                    try:
                        for chunk in response:
                            if chunk:
                                req.write(chunk)
                    finally:
                        if hasattr(response, "close"):
                            response.close()
                if req.close_connection:
                    return

Submodules [hide private]

Classes [hide private]
  SizeCheckWrapper
Wraps a file-like object, raising MaxSizeExceeded if too large.
  KnownLengthRFile
Wraps a file-like object, returning an empty string when exhausted.
  MaxSizeExceeded
  ChunkedRFile
Wraps a file-like object, returning an empty string when exhausted.
  HTTPRequest
An HTTP Request (and response).
  NoSSLError
Exception raised when a client speaks HTTP to an HTTPS socket.
  FatalSSLAlert
Exception raised when the SSL implementation signals a fatal alert.
  CP_fileobject
Faux file object attached to a socket object.
  HTTPConnection
An HTTP connection (active socket).
  WorkerThread
Thread which continuously polls a Queue for Connection objects.
  ThreadPool
A Request Queue for the CherryPyWSGIServer which pools threads.
  SSLAdapter
  HTTPServer
An HTTP server.
  Gateway
  CherryPyWSGIServer
  WSGIGateway
  WSGIGateway_10
  WSGIGateway_11
  WSGIGateway_u0
  WSGIPathInfoDispatcher
A WSGI dispatcher for dispatch based on the PATH_INFO.
Functions [hide private]
 
plat_specific_errors(*errnames)
Return error numbers for all errors in errnames on this platform.
source code
 
read_headers(rfile, hdict=None)
Read headers from the given stream into the given header dict.
source code
 
format_exc(limit=None)
Like print_exc() but return a string.
source code
 
prevent_socket_inheritance(sock)
Mark the given socket fd as non-inheritable (POSIX).
source code
 
get_ssl_adapter_class(name='pyopenssl') source code
Variables [hide private]
  CRLF = '\r\n'
  quoted_slash = re.compile(r'(?i)%2F')
  _fileobject_uses_str_type = False
  socket_error_eintr = [4]
  socket_errors_to_ignore = [32, 102, 103, 104, 9, 110, 111, 112...
  socket_errors_nonblocking = [11]
  comma_separated_headers = ['Accept', 'Accept-Charset', 'Accept...
  _SHUTDOWNREQUEST = None
hash(x)
  ssl_adapters = {'builtin': 'cherrypy.wsgiserver.ssl_builtin.Bu...
  wsgi_gateways = {(1, 0): <class 'web.web.wsgiserver.WSGIGatewa...
  __package__ = 'web.web.wsgiserver'
Function Details [hide private]

plat_specific_errors(*errnames)

source code 

Return error numbers for all errors in errnames on this platform.

The 'errno' module contains different global constants depending on the specific platform (OS). This function will return the list of numeric values for a given list of potential names.

read_headers(rfile, hdict=None)

source code 

Read headers from the given stream into the given header dict.

If hdict is None, a new header dict is created. Returns the populated header dict.

Headers which are repeated are folded together using a comma if their specification so dictates.

This function raises ValueError when the read bytes violate the HTTP spec. You should probably return "400 Bad Request" if this happens.

format_exc(limit=None)

source code 

Like print_exc() but return a string. Backport for Python 2.3.


Variables Details [hide private]

socket_errors_to_ignore

Value:
[32,
 102,
 103,
 104,
 9,
 110,
 111,
 112,
...

comma_separated_headers

Value:
['Accept',
 'Accept-Charset',
 'Accept-Encoding',
 'Accept-Language',
 'Accept-Ranges',
 'Allow',
 'Cache-Control',
 'Connection',
...

ssl_adapters

Value:
{'builtin': 'cherrypy.wsgiserver.ssl_builtin.BuiltinSSLAdapter',
 'pyopenssl': 'cherrypy.wsgiserver.ssl_pyopenssl.pyOpenSSLAdapter'}

wsgi_gateways

Value:
{(1, 0): <class 'web.web.wsgiserver.WSGIGateway_10'>,
 (1, 1): <class 'web.web.wsgiserver.WSGIGateway_11'>,
 ('u', 0): <class 'web.web.wsgiserver.WSGIGateway_u0'>}