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"""SCGI client resource and protocols.
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# * Handle scgi server death, half way through a resonse.
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from zope.interface import implements
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from twisted.internet import defer, protocol, reactor
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from twisted.protocols import basic
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from twisted.web2 import http, iweb, resource, responsecode, stream, twcgi
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class SCGIClientResource(resource.LeafResource):
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"""A resource that connects to an SCGI server and relays the server's
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response to the browser.
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This resource connects to a SCGI server on a known host ('localhost', by
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default) and port. It has no responsibility for starting the SCGI server.
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If the server is not running when a client connects then a BAD_GATEWAY
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response will be returned immediately.
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def __init__(self, port, host='localhost'):
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"""Initialise a SCGI client resource
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resource.LeafResource.__init__(self)
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def renderHTTP(self, request):
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return doSCGI(request, self.host, self.port)
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def doSCGI(request, host, port):
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if request.stream.length is None:
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return http.Response(responsecode.LENGTH_REQUIRED)
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factory = SCGIClientProtocolFactory(request)
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reactor.connectTCP(host, port, factory)
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return factory.deferred
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class SCGIClientProtocol(basic.LineReceiver):
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"""Protocol for talking to a SCGI server.
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def __init__(self, request, deferred):
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self.request = request
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self.deferred = deferred
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self.stream = stream.ProducerStream()
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self.response = http.Response(stream=self.stream)
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def connectionMade(self):
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# Ooh, look someone did all the hard work for me :).
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env = twcgi.createCGIEnvironment(self.request)
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# Send the headers. The Content-Length header should always be sent
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# first and must be 0 if not present.
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# The whole lot is sent as one big netstring with each name and value
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# separated by a '\0'.
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contentLength = str(env.pop('CONTENT_LENGTH', 0))
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scgiHeaders.append('%s\x00%s\x00'%('CONTENT_LENGTH', str(contentLength)))
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scgiHeaders.append('SCGI\x001\x00')
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for name, value in env.iteritems():
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if name in ('CONTENT_LENGTH', 'SCGI'):
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scgiHeaders.append('%s\x00%s\x00'%(name,value))
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scgiHeaders = ''.join(scgiHeaders)
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self.transport.write('%d:%s,' % (len(scgiHeaders), scgiHeaders))
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stream.StreamProducer(self.request.stream).beginProducing(self.transport)
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def lineReceived(self, line):
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# Look for end of headers
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# Switch into raw mode to recieve data and callback the deferred
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# with the response instance. The data will be streamed as it
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# arrives. Callback the deferred and set self.response to None,
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# because there are no promises that the response will not be
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# mutated by a resource higher in the tree, such as
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# log.LogWrapperResource
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self.deferred.callback(self.response)
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# Split the header into name and value. The 'Status' header is handled
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# specially; all other headers are simply passed onto the response I'm
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name, value = line.split(':',1)
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if name.lower() == 'status':
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value = value.split(None,1)[0]
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self.response.code = int(value)
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self.response.headers.addRawHeader(name, value)
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def rawDataReceived(self, data):
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self.stream.write(data)
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def connectionLost(self, reason):
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# The connection is closed and all data has been streamed via the
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# response. Tell the response stream it's over.
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class SCGIClientProtocolFactory(protocol.ClientFactory):
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"""SCGI client protocol factory.
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I am created by a SCGIClientResource to connect to an SCGI server. When I
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connect I create a SCGIClientProtocol instance to do all the talking with
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The ``deferred`` attribute is passed on to the protocol and is fired with
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the HTTP response from the server once it has been recieved.
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protocol = SCGIClientProtocol
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noisy = False # Make Factory shut up
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def __init__(self, request):
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self.request = request
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self.deferred = defer.Deferred()
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def buildProtocol(self, addr):
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return self.protocol(self.request, self.deferred)
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def clientConnectionFailed(self, connector, reason):
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self.sendFailureResponse(reason)
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def sendFailureResponse(self, reason):
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response = http.Response(code=responsecode.BAD_GATEWAY, stream=str(reason.value))
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self.deferred.callback(response)
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__all__ = ['SCGIClientResource']
added
removed
twisted/web2/twscgi.py
