Editing OpenSimulator Internals/Code Map/ROBUST/GridService RegisterRegion

= OpenSimulator Internals/Code Map/ROBUST/GridService RegisterRegion =

== RegisterRegion ==

Source: OpenSim/Services/GridService/GridService.cs

Validation sequence:

# RegionID must not be zero UUID
# RegionLocY must be above Constants.MaximumRegionSize (coordinates below this are reserved for HG links)
# Overlap check: queries m_Database.Get() for the bounding box. Fails if more than one overlap, or one overlap with a different RegionID
# Reservation check: existing record with Reservation flag rejects if PrincipalID is zero UUID, otherwise treated as an authentication request
# Authenticate flag check: verifies token via m_AuthenticationService.Verify(), 30-second window
# Duplicate name check (if AllowDuplicateNames = false): rejects if another region has the same name with a different RegionID
# Move check: if the region was previously registered at different coordinates, checks NoMove and LockedOut flags before deleting the old entry
# Applies DefaultRegionFlags from config, then per-region overrides by name or UUID (ParseFlags, supports +/- syntax)
# Sets RegionOnline flag unconditionally
# Stores via m_Database.Store() with last_seen timestamp

Returns empty string on success, an error message string on failure. Scene.RegisterRegionWithGrid() throws an Exception if the returned string is non-empty -- this is a fatal startup error in OpenSimBase.CreateRegion().

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== DeregisterRegion ==

```
public bool DeregisterRegion(UUID regionID)
{
    RegionData region = m_Database.Get(regionID, UUID.Zero);
    if (region == null)
        return false;
```

# Looks up the region by UUID, scope zero. Returns false if not found.
# Reads current flags.
# If !m_DeleteOnUnregister OR the region has the Persistent flag set: clears the RegionOnline flag, updates last_seen, calls Store(). Returns true.
# Otherwise: calls m_Database.Delete(regionID) and returns the result.

Called from Scene.Close() during simulator shutdown, and from the deregister region id console command on ROBUST.

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== See Also ==

* [[OpenSimulator Internals/GridService]]
* [[OpenSimulator Internals/Code Map/ROBUST]]
* [[OpenSimulator Internals/Databases]]