twisted.protocols.amp.ProtocolSwitchCommand

class documentation

class ProtocolSwitchCommand(Command): (source)

Use this command to switch from something Amp-derived to a different protocol mid-connection. This can be useful to use amp as the connection-startup negotiation phase. Since TLS is a different layer entirely, you can use Amp to negotiate the security parameters of your connection, then switch to a different protocol, and the connection will remain secured.

Class Method	`makeResponse`	Serialize a mapping of arguments using this `Command`'s response schema.
Method	`__init__`	Create a ProtocolSwitchCommand.
Instance Variable	`protoToSwitchToFactory`	Undocumented
Method	`_doCommand`	When we emit a ProtocolSwitchCommand, lock the protocol, but don't actually switch to the new protocol unless an acknowledgement is received. If an error is received, switch back.

Inherited from Command:

Class	`__metaclass__`	Metaclass hack to establish reverse-mappings for 'errors' and 'fatalErrors' as class vars.
Class Method	`makeArguments`	Serialize a mapping of arguments using this `Command`'s argument schema.
Class Method	`parseArguments`	Parse a mapping of serialized arguments using this `Command`'s argument schema.
Class Method	`parseResponse`	Parse a mapping of serialized arguments using this `Command`'s response schema.
Class Method	`responder`	Declare a method to be a responder for a particular command.
Class Variable	`arguments`	A list of 2-tuples of (name, Argument-subclass-instance), specifying the names and values of the parameters which are required for this command.
Class Variable	`commandType`	The type of Box used to issue commands; useful only for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla `Box`.
Class Variable	`errors`	A mapping of subclasses of `Exception` to wire-protocol tags for errors represented as `str`s. Responders which raise keys from this dictionary will have the error translated to the corresponding tag on the wire. Invokers which receive Deferreds from invoking this command with `BoxDispatcher.callRemote` will potentially receive Failures with keys from this mapping as their value. This mapping is inherited; if you declare a command which handles `FooError` as 'FOO_ERROR', then subclass it and specify `BarError` as 'BAR_ERROR', responders to the subclass may raise either `FooError` or `BarError`, and invokers must be able to deal with either of those exceptions.
Class Variable	`extra`	Undocumented
Class Variable	`fatalErrors`	like 'errors', but errors in this list will always terminate the connection, despite being of a recognizable error type.
Class Variable	`response`	A list like `arguments`, but instead used for the return value.
Class Variable	`responseType`	The type of Box used to respond to this command; only useful for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla `Box`.
Instance Variable	`requiresAnswer`	a boolean; defaults to True. Set it to False on your subclass if you want callRemote to return None. Note: this is a hint only to the client side of the protocol. The return-type of a command responder method must always be a dictionary adhering to the contract specified by `response`, because clients are always free to request a response if they want one.
Instance Variable	`structured`	Undocumented

@classmethod
def makeResponse(cls, innerProto, proto): (source)

overrides twisted.protocols.amp.Command.makeResponse

Serialize a mapping of arguments using this Command's response schema.

Parameters
innerProto	Undocumented
proto	an `AMP`.
objects	a dict with keys matching the names specified in self.response, having values of the types that the Argument objects in self.response can format.
Returns
an `AmpBox`.

def __init__(self, _protoToSwitchToFactory, **kw): (source)

overrides twisted.protocols.amp.Command.__init__

Create a ProtocolSwitchCommand.

Parameters
_protoToSwitchToFactory	a ProtocolFactory which will generate the Protocol to switch to.
**kw	Keyword arguments, encoded and handled normally as `Command` would.

protoToSwitchToFactory = (source)

Undocumented

def _doCommand(self, proto): (source)

overrides twisted.protocols.amp.Command._doCommand

When we emit a ProtocolSwitchCommand, lock the protocol, but don't actually switch to the new protocol unless an acknowledgement is received. If an error is received, switch back.