#!/usr/bin/env python
"""
FCGIAdapter.py
FCGI Adapter for the WebKit application environment.
Note: FCGI for Webware is not available on Windows.
This script is started by the Web Server and is kept running.
When a request comes through here, this script collects information
about the request, puts it into a package, and then invokes the
WebKit Application to handle it.
Original CGI implementaion by Chuck Esterbrook.
FastCGI Implementation by Jay Love.
Based on threaded fcgi example "sz_fcgi" provided by Andreas Jung.
SETUP
To use this adapter, you must have a fastcgi capable web server.
For Apache, you'll need to add the following lines to your httpd.conf file, or
put them in another file and include that file in httpd.conf
# I have the file in my cgi-bin directory, but you might as well put it in html.
# the -host is the port it communicates on
FastCgiExternalServer ../cgi-bin/FCGIWebKit.py -host localhost:33333 # the path is from the SERVER ROOT
#or whatever name you chose for the file above
SetHandler fastcgi-script
Options ExecCGI FollowSymLinks
You could also take an extension oriented approach in Apache using '.fcgi':
AddHandler fastcgi-script fcgi
And then using, in your URLs, 'WebKit.fcgi' which is a link to this file. e.g.,:
http://localhost/Webware/WebKit/WebKit.fcgi/Introspect
FUTURE
(*) There are some interesting lines at the top of fcgi.py:
# Set various FastCGI constants
# Maximum number of requests that can be handled
FCGI_MAX_REQS=1
FCGI_MAX_CONNS = 1
# Boolean: can this application multiplex connections?
FCGI_MPXS_CONNS=0
Do these need to be adjusted in order to realize the full benefits of FastCGI?
(*) Has anyone measured the performance difference between CGIAdapter and FCGIAdapter? What are the results?
JSL- It's twice as fast as straight CGI
CHANGES
* 2000-05-08 ce:
* Fixed bug in exception handler to send first message to stderr, instead of stdout
* Uncommented the line for reading 'adapter.address'
* Switched from eval() encoding to marshal.dumps() encoding in accordance with AppServer
* Increased rec buffer size from 8KB to 32KB
* Removed use of pr() for feeding app server results back to webserver. Figure that's slightly more efficient.
* Added notes about how I set this up with Apache to what was already there.
*2001-03-14 jsl:
* Fixed problem with post data
"""
# If the Webware installation is located somewhere else,
# then set the webwareDir variable to point to it here:
webwareDir = None
import sys, os, time
from socket import *
import fcgi
from Adapter import Adapter
class FCGIAdapter(Adapter):
def run(self):
"""Block waiting for new request."""
while fcgi.isFCGI():
req = fcgi.FCGI()
self.FCGICallback(req)
def FCGICallback(self,req):
"""This function is called whenever a request comes in."""
try:
# Transact with the app server
response = self.transactWithAppServer(req.env, req.inp.read(), host, port)
# deliver it!
req.out.write(response)
req.out.flush()
except:
import traceback
# Log the problem to stderr
stderr = req.err
stderr.write('[%s] [error] WebKit.FCGIAdapter:'
' Error while responding to request (unknown)\n'
% (time.asctime(time.localtime(time.time()))))
stderr.write('Python exception:\n')
traceback.print_exc(file=stderr)
# Report the problem to the browser
output = ''.join(traceback.format_exception(*sys.exc_info()))
output = HTMLEncode(output)
sys.pr('''Content-type: text/html\n
WebKit CGI Error
WebKit CGI Error
%s
\n''' % output)
req.Finish()
return
def pr(self, *args):
"""Just a quick and easy print function."""
try:
req=self.req
req.out.write(''.join(map(str, args)) + '\n')
req.out.flush()
except:
pass
HTMLCodes = [
['&', '&'],
['<', '<'],
['>', '>'],
['"', '"'],
]
def HTMLEncode(s, codes=HTMLCodes):
"""Return the HTML encoded version of the given string.
This is useful to display a plain ASCII text string on a web page.
(We could get this from WebUtils, but we're keeping CGIAdapter
independent of everything but standard Python.)
"""
for code in codes:
s = s.replace(code[0], code[1])
return s
# Start FCGI Adapter
if os.name != 'posix':
print "This adapter is only available on UNIX"
sys.exit(1)
fcgi._startup()
if not fcgi.isFCGI():
print "No FCGI Environment Available"
print "This module cannot be run from the command line"
sys.exit(1)
if not webwareDir:
webwareDir = os.path.dirname(os.path.dirname(os.getcwd()))
sys.path.insert(1, webwareDir)
webKitDir = os.path.join(webwareDir, 'WebKit')
os.chdir(webKitDir)
host, port = open(os.path.join(webKitDir, 'adapter.address')).read().split(':', 1)
port = int(port)
fcgiloop = FCGIAdapter(webKitDir)
fcgiloop.run()