Hypergrid 1.0

Revision as of 09:11, 7 March 2013

This was the original Hypergrid version started as a proof of concept by Diva in 2008. It was included in Opensimulator core at the end of that year and was relevant until HG 1.5 came out with opensimulator 7.0. in 2010. As it was an "exercise in feasibility" its focus was on the ability to jump between different Opensimulator grids and standalones and not on the security aspects. There are at the time of this writing some grids running this version of HG.

The Hypergrid Classes

Currently, the hypergrid is implemented outside of the OpenSimulator namespace, so that there is complete separation between what already exists and this new behavior. It has its own namespace, HyperGrid. In it, there are 4 sub-namespaces that follow directly the software architecture of OpenSim, namely: OpenSim.Framework:

ForeignUserProfileData extends UserProfileData by introducing information about the user's "home", namely the home address, port and remoting port. The user's home is not that user's user service; it's the opensim that the user has defined to be her home. This is necessary for supporting the home jump (Ctrl-Shift-H). 
HGNetworkServersInfo follows the spirit of NetworkServersInfo, although it neither extends it nor uses it. For now, it's a utility class whose two main functions are to convert domain names of servers to IP addresses, and to uniformly provide the answer to the question bool IsLocalUser(...). 

OpenSim.Region.Framework.Scenes.Hypergrid:

HGSceneCommunicationService extends SceneCommunicationService, overriding RequestTeleportToLocation. There are two very small but critical changes to the base method: (a) on the TeleportFinish event, we switch the region handles when the destination region is an hyperlink; (b) the connections at the end are always closed for hyperlink TPs. 
HGScene extends Scene, overriding TeleportClientHome(...). The only change to the base method is to stay away from the user server, for now, because the user service is still not completely wrapped up for foreign users. Once the user service is properly wrapped up, this class will become unnecessary. 
HGScene.Inventory is a partial class of HGScene, just like what happens in the OpenSimulator framework. This part of HGScene overrides some inventory-scene interaction methods, so that assets are fetched/posted from/to the user's asset server. Once that extra fetching/posting is done, these methods simply pass the ball to the base methods. 
HGAssetMapper: this is a new class specific to the hypergrid that manages the fetching and posting of assets between foreign regions where the user is and the user's asset server. 

OpenSim.Region.Communications.HyperGrid is a mashup of OpenSim.Region.Communications.*. This is the place where most of the hypergrid extension lies. One of the reasons for this is that the hypergrid communications part is doing one additional thing: it is making standalones network-able.

HGCommunicationsStandalone extends CommuniationsLocal. Just as its base, it is a hub for the several network services available in standalone mode. The main difference is that those services are extensions of what's in OpenSimulator. 
HGCommunicationsGridMode extends CommunicationsManager directly. Again, it's a hub for the network services available in grid mode, those services being extensions of OpenSimulator. 
The cluster HGGridServices (superclass), HGGridServicesStandalone and HGGridServicesGridMode (subclasses) implements the OpenSimulator interfaces IGridServices and IInterRegionCommunications. The 2 subclasses are wrappers for LocalBackEndServices and OGS1GridServices, respectively. There is one common pattern throughout these classes: check if the region to talk to is an hyperlink; if it's not, simply delegate the work to LocalBackEndServices/OGS1GridServices; if it is, push the work to the base class HGGridServices. HGGridServices, in turn, does the management of hyperlink regions, and defines two additional pieces of inter-region protocol: 
region_uuid: for linking regions 
expect_hg_user: similar to the existing expect_user interface, but with a lot more information about the user being passed around, namely all the user's servers (inventory, asset, user, home, etc.) 
HGInventoryService extends LocalInventoryService and implements ISecureInventoryService. This class is the most obvious mashup of the pack, mixing local service access for standalone users and remote inventory access for when users are out and about. Right now, there is a fair amount of selective copy-and-paste, to stay away from the ugliness coming from OGS1InventoryService and OGS1SecureInventoryService. HGInventoryService is always a ISecureInventoryService. Its methods all follow the same pattern: check if the user is a local standalone user; if it is, pass the work to the base method (in LocalInventoryService); if it's not perform secure remote access. 
HGUserServices wraps OSG1UserServices, but it's not functional yet. 

OpenSim.Region.CoreModules.HyperGrid is a collection of 3 region modules:

HGWorldMapModule extends WorldMapModule. It reuses almost everything from the base class. The only small change is in RequestMapBlocks, where it tries to send Offline mapblocks to the client. 
HGStandaloneInventoryService and HGStandaloneAssetService do what their names say. They are region modules that allow access to inventory and assets for standalones, when the standalone user is out and about. In spirit, there is a lot in common between these modules and the REST inventory/asset plugin. Unfortunately, that plugin could not be used because it defines a completely different interface than that used by existing inventory and asset servers, and the access for the hypergrid must use a consistent interface.