Tom Willans wrote: > Are some aspects of the interface more settled than others? I appreciate > that this is a judgement call.
Yes, some aspects are more settled than others. First, let me point out where this comes from, so that you and others can understand better. Up to recently, there was no such thing as OpenSim.Services.Interfaces, nor the companions OpenSim.Services.Connectors and OpenSim.Server.Handlers. The interaction between the simulator and the resource services, and among the resource services themselves, was a mess. I don't mean it in a criticizing attitude, early-stage code is usually a mess. The broad stokes were there, and were really good, but the details were a complete mess. Simple questions like "what handlers are there?" or "what are the resource service interfaces?" were a challenge to answer, interfaces and handlers were spread all over the code, special cases were pervasive, classes were being used directly instead of interfaces, etc. The user services, in particular, were a nightmare, with duplication running rampant because of "standalone vs grid mode", and the code being on the verge of bipolar disorder. Users, agents and avatars were being used interchangeably, with no conceptual distinction, misnomers everywhere, etc. This refactoring's main goal is to depart from that chaotic mess and to instill order in the code base. It is primarily a *refactoring*, meaning that code has moved from one namespace to another, but it is also a rewrite -- because in the process of revisiting the code it was clear that things should be done better than they were being done. In particular, harmful hard-coded instantiations of classes were replaced by dynamic loading and instantiation. The core of this is OpenSim.Server.Base.Utils.LoadPlugin -- this is the core of the ROBUST model. Having said that, let me now explain how people who plan to extend OpenSim should be looking at it. The main "contract" between the core code and developers of resource services is the collection of interfaces in OpenSim.Services.Interfaces. This is what the simulators call, can't get around hard-coded calls to those interfaces. Those interfaces will stabilize very quickly. Most of them are stable already, with the notable exception of IInventoryService which still needs love. But all others will be stable at 0.7. Now is the right time for people to look at those interfaces and send feedback about which things you think are missing. The next level of reuse is the code in OpenSim.Services.Connectors and OpenSim.Server.Handlers. This code is less important than the interfaces, because it's invisible to the simulators, therefore ppl should be more careful about relying on it. This is quite an important point that I don't think many people grasp yet, so let me explain. In most systems, the network protocols are fixed. People go to great lengths discussing them ad-nauseum in meetings and committees, to settle on the right data formats, the right data, etc. NOT HERE. The network protocols in OpenSim are now dynamically loaded, and therefore replaceable. There is no such thing as *the* network protocol between the simulator and, say, the asset server. There can be many -- you can roll your own. There are reference implementations in the core distribution, but that's exactly what they are: reference implementations, they are not fixed protocols. As such, people should be careful about relying on those reference implementations. So, to sum it up: the main contract is OpenSim.Services.Interfaces and those are going to be stable very soon. The level right under it, OpenSim.Server.Handlers and OpenSim.Services.Connectors can also be relied upon but it's less stable. I'm still not happy with many of those, so they will change after 0.7. People who don't want to put up with these changes may want to roll their own network protocols. _______________________________________________ Opensim-dev mailing list [email protected] https://lists.berlios.de/mailman/listinfo/opensim-dev
