[Opensim-dev] dispatcher interface

Sat Dec 20 02:16:29 UTC 2014

I would be happy to see this in core.  I do have the following questions/points.  I would ideally like to see much of 
this stuff in a feature proposal page [1] and that can later also become some documentation.

1.  Please could you go into detail about the authentication/access model.  Looking over the code, I see text about 
domains, capabilities, authentication by hashed password, etc. but I would like an overview on how this fits together.

2.  Please could you give an example serialization of one of the JSON messages.  I would like to see the basic form and 
what one expects to see in such a message.

3.  This would be yet another different kind of message passing in OpenSimulator, to join XMLRPC, JSON RPC, form, etc, 
where the majority of internal communication is via XMLRPC.  I'm not saying we should persist with XMLRPC in this case, 
but I would really like to see some agreement on how communication should evolve in the future, whether that should be 
JSON/BSON or something else.

4.  I don't feel that we should change our rule of only having C# code in core.  Having other languages or client code 
increases project complexity and implies a commitment to maintain code which is not part of the server system (hence I 
think one could make a case for separating out pCampbot but that's another topic).  I think it's fine for the client 
code to be external as long as there are open-source clients under a permissive license (Vivox being a historical 
exception) and the interfaces are documented.

5.  Regarding documentation, to be clear I think wiki pages will be required documenting the general approach, security 
model, etc.

6.  In this case, I don't think that this facility should be enabled by default as it does expose a method of 
interacting with the simulator with security implications, even on a private network.

7.  I see all the license notices are BSD but with an extra "EXPORT LAWS" text which I find rather bizarre as it 
purports to add "NO RESTRICTIONS TO THE EXPORT LAWS OF YOUR JURISDICTION".  I find this rather bizarre (why have such a 
paragraph if it doesn't do anything?).  Apparantly, Intel itself has ceased to use or recommend this license text [2] 
and has asked the OSI to remove it for future use as an approved license back in 2005 [3].  Is it going to be a problem 
to remove this text before adding any code into core?

[1] http://opensimulator.org/wiki/Feature_Proposals
[2] https://en.wikipedia.org/wiki/Intel_Open_Source_License
[3] http://news.cnet.com/Intel-to-stop-using-open-source-license/2100-7344_3-5648518.html

On 19/12/14 00:11, Mic Bowman wrote:
> i've had several requests for the dispatcher interface to be moved into core. dispatcher package consists of two pieces:
>
> dispatcher -- the core modules that implement the message transfer, message encoding and some of the basic messages
> (informational messages and messages to create and renew access capabilities).
>
> https://github.com/cmickeyb/scisim-addons/tree/master/dispatcher
>
> remote control -- a collection of messages that implement a OpenSim remote scripting API. these messages include some
> basics for accessing/creating assets, for getting/setting avatar appearance, sending messages, managing objects in the
> scene, and managing some of the region characteristics. there are also messages for registering remote handlers for
> touch events. clearly this is just a start (though there is a surprisingly large number of things you can do with these).
>
> https://github.com/cmickeyb/scisim-addons/tree/master/rcontrol
>
> for more information on what the dispatcher is and why you might want to use it, watch the OSCC presentation
> http://www.ustream.tv/recorded/55195110 or take a look at the kinds of scripts that you can write by looking in the
> scripts directory of the rcontrol repository.
>
> with all that said...
>
> i would like to start the discussion about whether this is useful enough to be moved into core & how that should happen.
>
> i don't have a particular stake in whether its moved to core. there are benefits to both. its easier for me to change
> for my purposes if if its outside core and its (much) easier for the community to use it if its in core. if the
> community believes there is sufficient value, then we should move it in.
>
> if it is not moved inside, i would appreciate suggestions on how to distribute the libraries. this is an ongoing problem
> for opensim... how to provide simple access to a dynamic set of region modules. probably a bigger discussion.
>
> if we think the dispatcher API should be moved into core, then there are a few questions about how that should happen.
> clearly the region modules can be moved into OpenSim/Region/OptionalModules. that's easy. the more interesting question
> is where to put the client libraries (these are the perl & python libraries that are used to build dispatcher clients)
> and the control scripts that are rather useful for managing a region. I would propose placing them in a directory under
> OpenSim/Tools though they really aren't tools in the sense of the other packages in that directory.
>
> the final question is about documentation. the api is already pseudo-self documenting... the API lets you can ask any
> simulator for the messages it supports & then ask for examples of the messages themselves. i'm planning to add a
> "documentation" string for each as well. some other methods for autodoc would be useful though pulling out dispatcher
> documentation from within the multitude of existing opensim autodoc might be challenging (not something i have any
> experience with).
>
> --mic
>
>
>
>
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