def callRemote(self, command, **kw):
"""
Asyncronously call a remote AMP command.
"""
# compose packet
dataList = [ampy.COMMAND, command.commandName]
retVal = None
# remember that we sent this command if a response is expected
if command.requiresAnswer:
# XXX TODO a race condition exists between the two lines below
askKey = str(self.counter)
self.counter += 1
retVal = defer.Deferred()
self.awaitingResponse[askKey] = (command, retVal)
dataList.extend( [ampy.ASK, askKey] )
#for kv in COMMAND, command.commandName, ASK, askKey:
# dataList.append(struct.pack('!H', len(kv)))
# dataList.append(kv)
command.serializeRequest(dataList, kw)
ampy.insertPrefixes(dataList)
data = ''.join(dataList)
# write packet
self.push(data)
return retVal
def _eb_gotResponseError(self, f, command, askKey):
key = f.check(*command.errors.keys())
if key:
code = command.errors[key]
descr = "" # TODO what should go here?
else:
sys.stderr.write("Unhandled exception raised in AMP Command handler:\n")
f.printTraceback()
code = ampy.UNKNOWN_ERROR_CODE
descr = "Unknown Error"
resp = [ampy.ERROR, askKey,
ampy.ERROR_CODE, code,
ampy.ERROR_DESCRIPTION, descr]
self.push(''.join(ampy.insertPrefixes(resp)))
def processFullMessage(self, box):
if ampy.COMMAND in box:
cmdName = box[ampy.COMMAND]
command, handler = self.responders.get(cmdName, (None, None))
askKey = box.get(ampy.ASK, None)
if not handler:
if askKey:
resp = [ampy.ERROR, askKey,
ampy.ERROR_CODE, ampy.UNHANDLED_ERROR_CODE,
ampy.ERROR_DESCRIPTION, "No handler for command"]
self.push(''.join(ampy.insertPrefixes((resp))))
else:
kw = command.deserializeRequest(box)
if askKey:
defer.maybeDeferred(handler, **kw).addCallbacks(self._cb_gotResponse, self._eb_gotResponseError,
callbackArgs=(command, askKey), errbackArgs=(command, askKey))
else:
handler(**kw)
elif ampy.ANSWER in box:
answerKey = box[ampy.ANSWER]
command, deferred = self.awaitingResponse.pop(answerKey, (None,None) )
if command:
kw = command.deserializeResponse(box)
deferred.callback(kw)
else:
sys.stderr.write("Got answer key %s, but we weren't waiting for it! weird!\n" % (answerKey,))
elif ampy.ERROR in box:
errorKey = box[ampy.ERROR]
command, deferred = self.awaitingResponse.pop(errorKey, (None,None) )
if command:
e = ampy.AMPError(box[ampy.ERROR_CODE], box[ampy.ERROR_DESCRIPTION])
deferred.errback(e)
else:
sys.stderr.write("Got error key %s, but we weren't waiting for it! weird!\n" % (errorKey,))
else:
sys.stderr.write("Insane AMP packet!\n")
def _cb_gotResponse(self, kw, command, askKey):
dataList = [ampy.ANSWER, askKey]
command.serializeResponse(dataList, kw)
self.push(''.join(ampy.insertPrefixes(dataList)))