Perspective Broker

"This isn't a professional opinion, but it's probably got enough internet to kill you." --glyph

Future Plans: The connection APIs will be extended with support for URLs, that will be able to extend resource location and discovery conversations and specify different authentication mechanisms besides username/password. This should only add to, and not change, the existing protocol.

Important Changes

New APIs have been added for serving and connecting. On the client side, use PBClientFactory.getPerspective() instead of connect(), and PBClientFactory.getRootObject() instead of getObjectAt(). Server side should switch to updated cred APIs by using PBServerFactory, at which point clients would switch to PBClientFactory.login().

The new cred support means a different method is sent for login, although the protocol is compatible on the binary level. When we switch to pluggable credentials this will introduce another change, although the current change will still be supported.

The Perspective class is now deprecated, and has been replaced with Avatar, which does not rely on the old cred APIs.

Introduction

This is a broker for proxies for and copies of objects. It provides a translucent interface layer to those proxies.

The protocol is not opaque, because it provides objects which represent the remote proxies and require no context (server references, IDs) to operate on.

It is not transparent because it does not attempt to make remote objects behave identically, or even similiarly, to local objects. Method calls are invoked asynchronously, and specific rules are applied when serializing arguments.

Author

Glyph Lefkowitz

Class	ProtocolError	This error is raised when an invalid protocol statement is received.
Class	DeadReferenceError	This error is raised when a method is called on a dead reference (one whose broker has been disconnected).
Class	Error	This error can be raised to generate known error conditions.
Class	RemoteMethod	This is a translucent reference to a remote message.
Function	noOperation	Do nothing.
Class	PBConnectionLost	Undocumented
Function	printTraceback	Print a traceback (string) to the standard log.
Interface	IPerspective	per*spec*tive, n. : The relationship of aspects of a subject to each other and to a whole: 'a perspective of history'; 'a need to view the problem in the proper perspective'.
Class	Avatar	A default IPerspective implementor.
Class	AsReferenceable	AsReferenceable: a reference directed towards another object.
Class	RemoteReference	This is a translucent reference to a remote object.
Class	Local	(internal) A reference to a local object.
Class	CopyableFailure	A flavors.RemoteCopy and flavors.Copyable version of twisted.python.failure.Failure for serialization.
Class	CopiedFailure	Undocumented
Function	failure2Copyable	Undocumented
Class	Broker	I am a broker for objects.
Function	respond	Respond to a challenge.
Function	challenge	I return some random data.
Class	PBClientFactory	Client factory for PB brokers.
Class	PBServerFactory	Server factory for perspective broker.
Interface	IUsernameMD5Password	I encapsulate a username and a hashed password.
Class	_RemoteCacheDummy	Ignore.
Class	_PortalRoot	Root object, used to login to portal.
Class	_JellyableAvatarMixin	Helper class for code which deals with avatars which PB must be capable of sending to a peer.
Class	_PortalWrapper	Root Referenceable object, used to login to portal.
Class	_PortalAuthChallenger	Called with response to password challenge.