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# -*- Mode: Python -*-
# This is a simple python server-side script handler.
# A note about performance: This is really only suited for 'fast'
# scripts: The script should generate its output quickly, since the
# whole web server will stall otherwise. This doesn't mean you have
# to write 'fast code' or anything, it simply means that you shouldn't
# call any long-running code, [like say something that opens up an
# internet connection, or a database query that will hold up the
# server]. If you need this sort of feature, you can support it using
# the asynchronous I/O 'api' that the rest of medusa is built on. [or
# you could probably use threads]
# Put your script into your web docs directory (like a cgi-bin
# script), make sure it has the correct extension [see the overridable
# script_handler.extension member below].
#
# There's lots of things that can be done to tweak the restricted
# execution model. Also, of course you could just use 'execfile'
# instead (this is now the default, see class variable
# script_handler.restricted)
import rexec
import re
import string
import StringIO
import sys
import counter
import default_handler
import producers
unquote = default_handler.unquote
class script_handler:
extension = 'mpy'
restricted = 0
script_regex = re.compile (
r'.*/([^/]+\.%s)' % extension,
re.IGNORECASE
)
def __init__ (self, filesystem):
self.filesystem = filesystem
self.hits = counter.counter()
self.exceptions = counter.counter()
def match (self, request):
[path, params, query, fragment] = request.split_uri()
m = self.script_regex.match (path)
return (m and (m.end() == len(path)))
def handle_request (self, request):
[path, params, query, fragment] = request.split_uri()
while path and path[0] == '/':
path = path[1:]
if '%' in path:
path = unquote (path)
if not self.filesystem.isfile (path):
request.error (404)
return
else:
self.hits.increment()
request.script_filename = self.filesystem.translate (path)
if request.command in ('PUT', 'POST'):
# look for a Content-Length header.
cl = request.get_header ('content-length')
length = int(cl)
if not cl:
request.error (411)
else:
collector (self, length, request)
else:
self.continue_request (
request,
StringIO.StringIO() # empty stdin
)
def continue_request (self, request, stdin):
temp_files = stdin, StringIO.StringIO(), StringIO.StringIO()
old_files = sys.stdin, sys.stdout, sys.stderr
if self.restricted:
r = rexec.RExec()
try:
sys.request = request
sys.stdin, sys.stdout, sys.stderr = temp_files
try:
if self.restricted:
r.s_execfile (request.script_filename)
else:
execfile (request.script_filename)
request.reply_code = 200
except:
request.reply_code = 500
self.exceptions.increment()
finally:
sys.stdin, sys.stdout, sys.stderr = old_files
del sys.request
i,o,e = temp_files
if request.reply_code != 200:
s = e.getvalue()
else:
s = o.getvalue()
request['Content-Length'] = len(s)
request.push (s)
request.done()
def status (self):
return producers.simple_producer (
'<li>Server-Side Script Handler'
+ '<ul>'
+ ' <li><b>Hits:</b> %s' % self.hits
+ ' <li><b>Exceptions:</b> %s' % self.exceptions
+ '</ul>'
)
class persistent_script_handler:
def __init__ (self):
self.modules = {}
self.hits = counter.counter()
self.exceptions = counter.counter()
def add_module (self, name, module):
self.modules[name] = module
def del_module (self, name):
del self.modules[name]
def match (self, request):
[path, params, query, fragment] = request.split_uri()
parts = string.split (path, '/')
if (len(parts)>1) and self.modules.has_key (parts[1]):
module = self.modules[parts[1]]
request.module = module
return 1
else:
return 0
def handle_request (self, request):
if request.command in ('PUT', 'POST'):
# look for a Content-Length header.
cl = request.get_header ('content-length')
length = int(cl)
if not cl:
request.error (411)
else:
collector (self, length, request)
else:
self.continue_request (request, StringIO.StringIO())
def continue_request (self, request, input_data):
temp_files = input_data, StringIO.StringIO(), StringIO.StringIO()
old_files = sys.stdin, sys.stdout, sys.stderr
try:
sys.stdin, sys.stdout, sys.stderr = temp_files
# provide a default
request['Content-Type'] = 'text/html'
try:
request.module.main (request)
request.reply_code = 200
except:
request.reply_code = 500
self.exceptions.increment()
finally:
sys.stdin, sys.stdout, sys.stderr = old_files
i,o,e = temp_files
if request.reply_code != 200:
s = e.getvalue()
else:
s = o.getvalue()
request['Content-Length'] = len(s)
request.push (s)
request.done()
class collector:
def __init__ (self, handler, length, request):
self.handler = handler
self.request = request
self.request.collector = self
self.request.channel.set_terminator (length)
self.buffer = StringIO.StringIO()
def collect_incoming_data (self, data):
self.buffer.write (data)
def found_terminator (self):
self.buffer.seek(0)
self.request.collector = None
self.request.channel.set_terminator ('\r\n\r\n')
self.handler.continue_request (
self.request,
self.buffer
)
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