[Opensim-dev] Rethinking inventory

[Melanie]

Hello Diva,

to answer your questions:

The inventory skeleton is fetched on login and sent to the client. 
It contains (or SHOULD contain) the actual folder serial numbers. I 
believe they may not currently be correct, though. The client 
decides, on opening a folder, which are out of date (by the serial 
number) and requests them.

I implemented the serial number thing not too long ago, before then, 
inventory was always completely reloaded, the client cache was in 
fact defeated. In part, that is still so (see above).

Inventory was implemented in a rather simplistic manner, sending the 
entire inventory in a single transaction from the inventory server 
to the client. This was never really necessary, and often not even 
useful, since all inventory transactions depend on the root folder, 
and it can't be loaded without loading all folders.

A better inventory service would load inventory to regions only when 
it needs to be loaded, and the cases where that is necessary are 
surprisingly few, and most could get away with just the folder 
skeleton and individual items.

I believe that I could get away with a function that will fetch only 
the user's root and system folders' UUIDs, since they are what is 
needed for inventory gives.

For take and rez, the client already knows the folder IDs. So 
dropping inventory on a user and scripted gives are the two things a 
region does with client inventory.

About letting the client talk to the inventory server: It needs to 
remain possible to do it through a region, as some grids are not 
willing to expose their inventory (asset, grid, etc) server ports to 
the internet. The region could, however, just verify the session and 
pass the request on.

Session_lookup doesn't work. It was an attempt to secure the 
inventory server that failed because of session caches. If the 
inventory server needed to be restarted, it all currently logged in 
users would lose inventory access until relog. It was found 
architecturally flawed and not salvageable, so was turned off by 
default and recommended to be kept off. New implementations don't 
need to support the mechanism.

So, a possible interface could be:

class UserInventory
{
	UUID RootFolder;
	Dictionary<int, IventoryFolderBase> SystemFolders; // System 
folders by content type
	List <InventoryItemBase> Items; // Cache for those items a region 
actually uses
}

interface IInventoryService
{
	UserInventory GetInventoryBase();
	List<InventoryFolderBase> GetInventorySkel(); // Used by userserver 
for logins
	InventoryItemBase GetItem(UUID item);
	List<InventoryItemBase> GetFolderItems(UUID folderID);
	bool StoreItem(InventoryItemBase item); // Will overwrite by UUID
}

GetItem() is needed to push newly acquired items to the client as 
well as to verify that asset IDs given by the client on rez are 
correct. We currently don't trust the IDs the client produces, and 
we shouldn't.

GetInventoryBase is what the "give" class of functions would call on 
users who are not logged into a region. We may want to call that 
when a user enters the region, but possibly we can actually get away 
with not obtaining any inventory information at all unless an object 
gives something to the user, or another user does.

Note the distinct lack of a "GetAllIventory" type method... it's not 
needed.

It may need a few more specialized methods, but this should be about 
the size of it.

Melanie



diva at metaverseink.com wrote:
> Also, are there any grid operators out there who run their inventory 
> servers with the configuration session_lookup = true ? (this is a flag 
> in InventoryServer_Config.xml)
> Just curious to know if this is being used.
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