This recipe shows how to build an xmlrpc multithread server that exposes a COM component as a web service.
Python, 71 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | # a python COM object (it's a standard sample, I've reported it here only
# to let the recipe be complete (file testcomserver.py).
##################################################
class HelloWorld:
_reg_clsid_ = "{7CC9F362-486D-11D1-BB48-0000E838A65F}"
_reg_desc_ = "Python Test COM Server"
_reg_progid_ = "Python.TestServer"
# Next line assumes file is "testcomserver.py"
_reg_class_spec_ = "testcomserver.HelloWorld"
_public_methods_ = ['Hello']
_public_attrs_ = ['softspace', 'noCalls']
_readonly_attrs_ = ['noCalls']
def __init__(self):
self.softspace = 1
self.noCalls = 0
def Hello(self, who):
self.noCalls = self.noCalls + 1
# insert "softspace" number of spaces
return "Hello" + " " * self.softspace + str(who)
if __name__=='__main__':
import win32com.server.register
win32com.server.register.UseCommandLine(HelloWorld)
##################################################
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# the CherryPy (v.0.10) server definition file (file testXmlRpc.cpy)
def initProgram():
import win32com.client, pythoncom, time
def initThread(threadIndex):
time.sleep(threadIndex * 0.2)
# start the COM environment in a MT situation
pythoncom.CoInitialize()
# dispatch a COM object to each thread via "request" reserved variable
request.x=win32com.client.Dispatch("Python.TestServer")
CherryClass Xml_rpc:
view:
def hello(self, a) xmlrpc:
# Return the COM hello method
return request.x.hello(a)
def nocalls(self) xmlrpc:
# Return the COM noCalls variable
return request.x.noCalls
##################################################
##################################################
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# the CherryPy server configuration file (file testXmlRpcServer.cfg)
[server]
typeOfRequests=xmlRpc,web
threadPool=3
##################################################
##################################################
##################################################
# a client test program
import xmlrpclib, time
if __name__=='__main__':
testsvr = xmlrpclib.Server("http://127.0.0.1:8000")
print testsvr.xml.rpc.hello("I love cherry pie " + str(x))
print testsvr.xml.rpc.nocalls()
raw_input("press a key:...")
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It's a standard problem to be able to invoke a legacy COM component from a web application: this is an application of the "remote facade" patter to this issue. All the magic is in the initThread(threadIndex) method: here we had to be sure there's a distinct COM object for each server thread, in order to avoid collision in its usage. The CherryPy xmlrpc methods are simply wrappers for COM-exposed entities.
As reference search google for "python win32com CoInitialize" and "cherrypy thread pool".
Tags: distributed
