# This is a sample ISAPI extension written in Python.
# This is like the other 'redirector' samples, but uses asnch IO when writing
# back to the client (it does *not* use asynch io talking to the remote
# server!)
from isapi import isapicon,threaded_extension
import sys
import traceback
import urllib
# sys.isapidllhandle will exist when we are loaded by the IIS framework.
# In this case we redirect our output to the win32traceutil collector.
if hasattr(sys, "isapidllhandle"):
import win32traceutil
# The site we are proxying.
proxy = "http://www.python.org"
# We synchronously read chunks of this size then asynchronously write them.
CHUNK_SIZE=8192
# The callback made when IIS completes the asynch write.
def io_callback(ecb, fp, cbIO, errcode):
print "IO callback", ecb, fp, cbIO, errcode
chunk = fp.read(CHUNK_SIZE)
if chunk:
ecb.WriteClient(chunk, isapicon.HSE_IO_ASYNC)
# and wait for the next callback to say this chunk is done.
else:
# eof - say we are complete.
fp.close()
ecb.DoneWithSession()
# The ISAPI extension - handles all requests in the site.
class Extension(threaded_extension.ThreadPoolExtension):
"Python sample proxy server - asynch version."
def Dispatch(self, ecb):
print 'IIS dispatching "%s"' % (ecb.GetServerVariable("URL"),)
url = ecb.GetServerVariable("URL")
new_url = proxy + url
print "Opening %s" % new_url
fp = urllib.urlopen(new_url)
headers = fp.info()
ecb.SendResponseHeaders("200 OK", str(headers) + "\r\n", False)
# now send the first chunk asynchronously
ecb.ReqIOCompletion(io_callback, fp)
chunk = fp.read(CHUNK_SIZE)
if chunk:
ecb.WriteClient(chunk, isapicon.HSE_IO_ASYNC)
return isapicon.HSE_STATUS_PENDING
# no data - just close things now.
ecb.DoneWithSession()
return isapicon.HSE_STATUS_SUCCESS
# The entry points for the ISAPI extension.
def __ExtensionFactory__():
return Extension()
if __name__=='__main__':
# If run from the command-line, install ourselves.
from isapi.install import *
params = ISAPIParameters()
# Setup the virtual directories - this is a list of directories our
# extension uses - in this case only 1.
# Each extension has a "script map" - this is the mapping of ISAPI
# extensions.
sm = [
ScriptMapParams(Extension="*", Flags=0)
]
vd = VirtualDirParameters(Name="/",
Description = Extension.__doc__,
ScriptMaps = sm,
ScriptMapUpdate = "replace"
)
params.VirtualDirs = [vd]
HandleCommandLine(params)
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