1 # hgweb/wsgicgi.py - CGI->WSGI translator

     2 #

     3 # Copyright 2006 Eric Hopper <hopper@omnifarious.org>

     4 #

     5 # This software may be used and distributed according to the terms

     6 # of the GNU General Public License, incorporated herein by reference.

     7 #

     8 # This was originally copied from the public domain code at

     9 # http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side

    10 

    11 import os, sys

    12 

    13 def launch(application):

    14 

    15     environ = dict(os.environ.items())

    16     environ['wsgi.input']        = sys.stdin

    17     environ['wsgi.errors']       = sys.stderr

    18     environ['wsgi.version']      = (1,0)

    19     environ['wsgi.multithread']  = False

    20     environ['wsgi.multiprocess'] = True

    21     environ['wsgi.run_once']    = True

    22 

    23     if environ.get('HTTPS','off') in ('on','1'):

    24         environ['wsgi.url_scheme'] = 'https'

    25     else:

    26         environ['wsgi.url_scheme'] = 'http'

    27 

    28     headers_set = []

    29     headers_sent = []

    30 

    31     def write(data):

    32         if not headers_set:

    33              raise AssertionError("write() before start_response()")

    34 

    35         elif not headers_sent:

    36              # Before the first output, send the stored headers

    37              status, response_headers = headers_sent[:] = headers_set

    38              sys.stdout.write('Status: %s\r\n' % status)

    39              for header in response_headers:

    40                  sys.stdout.write('%s: %s\r\n' % header)

    41              sys.stdout.write('\r\n')

    42 

    43         sys.stdout.write(data)

    44         sys.stdout.flush()

    45 

    46     def start_response(status,response_headers,exc_info=None):

    47         if exc_info:

    48             try:

    49                 if headers_sent:

    50                     # Re-raise original exception if headers sent

    51                     raise exc_info[0], exc_info[1], exc_info[2]

    52             finally:

    53                 exc_info = None     # avoid dangling circular ref

    54         elif headers_set:

    55             raise AssertionError("Headers already set!")

    56 

    57         headers_set[:] = [status,response_headers]

    58         return write

    59 

    60     result = application(environ, start_response)

    61     try:

    62         for data in result:

    63             if data:    # don't send headers until body appears

    64                 write(data)

    65         if not headers_sent:

    66             write('')   # send headers now if body was empty

    67     finally:

    68         if hasattr(result,'close'):

    69             result.close()