Python Lover(8)Twisted Basic - async - logging
TwistedNerve 2015-09-17
PythonLover(8)TwistedBasic-async-logging
1.AsynchronousResponse
http://twistedmatrix.com/documents/current/web/howto/web-in-60/asynchronous.html
BasicDifferences
Wedonotdirectlyresponsestring,wecallRequest.write.Wecancallrequest.writemanytimes,aftertheentireresponsebodyhasbeenpassedtoRequest.write,theapplicationmustcallRequest.finish.
fromtwisted.web.resourceimportResource
fromtwisted.web.serverimportNOT_DONE_YET
fromtwisted.internetimportreactor
classDeplayedResource(Resource):
def_deplayedRender(self,request):
request.write("""
<html>
<body>
Sorrytokeepyouwaiting.
</body>
</html>
""")
defrender_GET(self,request):
reactor.callLater(5,self._deplayedRender,request)#delay5seconds
returnNOT_DONE_YET
resource=DeplayedResource()
Commandtostart
>twistd-nweb--path.
Visitthispagetoverify
http://localhost:8080/RestAPI.rpy
2.DeferredinAsyncResponse
http://twistedmatrix.com/documents/current/web/howto/web-in-60/asynchronous-deferred.html
Deferredprovidescallbacksanderrbacks.
Deferred.addCallbackDeferred.callback
Deferred.addErrbackDeferred.errback
fromtwisted.internet.taskimportdeferLater
fromtwisted.web.resourceimportResource
fromtwisted.web.serverimportNOT_DONE_YET
fromtwisted.internetimportreactor
classDelayedResource(Resource):
def_delayedRender(self,request):
request.write("""
<html>
<body>
Sorrytokeepyouwaiting.
</body>
</html>
""")
request.finish()
defrender_GET(self,request):
d=deferLater(reactor,5,lambda:request)
d.addCallback(self._delayedRender)
returnNOT_DONE_YET
resource=DelayedResource()
3.InterruptedResponse
http://twistedmatrix.com/documents/current/web/howto/web-in-60/interrupted.html
Sincewedoasync,sometimes,wehavenotfinishedgeneratetheresult,buttheclientconnectionsareclose,soweneedtoabandontheresponsegenerationentirely.
CanceltheGenerationProcess
fromtwisted.web.resourceimportResource
fromtwisted.web.serverimportNOT_DONE_YET
fromtwisted.internetimportreactor
classDelayedResource(Resource):
def_delayedRender(self,request):
request.write("""
<html>
<body>
Sorrytokeepyouwaiting.
</body>
</html>
""")
request.finish()
def_responseFailed(self,err,call):
call.cancel()
defrender_GET(self,request):
call=reactor.callLater(5,self._delayedRender,request)
request.notifyFinish().addErrback(self._responseFailed,call)
returnNOT_DONE_YET
resource=DelayedResource()
4.LoggingError
http://twistedmatrix.com/documents/current/web/howto/web-in-60/logging-errors.html
fromtwisted.web.resourceimportResource
fromtwisted.web.serverimportNOT_DONE_YET
fromtwisted.internetimportreactor
fromtwisted.python.logimporterr
classDelayedResource(Resource):
def_delayedRender(self,request):
request.write("""
<html>
<body>
Sorrytokeepyouwaiting.
</body>
</html>
""")
request.finish()
def_responseFailed(self,failure,call):
call.cancel()
err(failure,"Asyncresponsedemointerruptedresponse")
defrender_GET(self,request):
call=reactor.callLater(5,self._delayedRender,request)
request.notifyFinish().addErrback(self._responseFailed,call)
returnNOT_DONE_YET
resource=DelayedResource()
Thesemessagewilldisplaywhenwecanceltheclientrequest.
2015-09-1614:00:36-0500[HTTPChannel,0,127.0.0.1]Asyncresponsedemointerruptedresponse
Traceback(mostrecentcalllast):
Failure:twisted.internet.error.ConnectionDone:Connectionwasclosedcleanly.
5.AccessLogging
http://twistedmatrix.com/documents/current/web/howto/web-in-60/access-logging.html
Wecanconfiguretheloggingin2differentways.
factory=Site(root,logPath=b”/tmp/access-logging-demo.log”)
or
>twistd-nweb--logfile/tmp/access-logging-demo.log
>twistd-nweb--path.--logfile./RestAPI.access.log
References:
http://twistedmatrix.com/documents/15.0.0/core/howto/index.html
http://twistedmatrix.com/documents/current/web/howto/web-in-60/
deployment
http://twistedmatrix.com/trac/wiki/TwistedWeb
https://github.com/todddeluca/daemoncmd
https://bitbucket.org/tildeslash/monit/
