[Opensim-dev] Proposal to eliminate the name, description and invType fields from the assets db table

[Melanie]

But, as far as I believe, if two people upload the exact same asset, 
they should not be coalesced. I know I would not want that to happen 
on my grid.

It would rob me, as a content creator, rob me of the ability to 
determine whether they used my texture ID via script, or uploaded a 
copy (which will cause the asset ID to be different).
When using SHA hashing, the second uploader would be handed the same 
ID, which, from my point of view, is not desired.

Also, in the case of a hash collision (same hash for different 
items), the uploader would be getting my texture instead of his, not 
what he wants. He would basically be handed a full perm copy of a 
texture I may have taken hours to create.

So, since duplicate prevention is not proper to attempt, hashing 
seems pointless.

Melanie


Sean Dague wrote:
> On Mon, Jun 23, 2008 at 02:47:18PM +0100, Melanie wrote:
>> What is the purpose of creating UUIDs by hashing? If it's not 
>> duplicate detection/prevention, I see no reason. GUIDs are supposed 
>> to be random, I believe.
> 
> If you look at GUID allocation in the RFC, the type 5 GUID is sha1
> based.  It is a modified version of the sha1 algorithm plus reserved
> bytes to identify types.
> 
> One of the reasons for this approach is duplicate prevention, both
> internally and externally.  For the average case of people uploading
> assets this will help a little on both code savings and packet savings
> in only sending out exactly 1 version of an asset even if people
> uploaded the same basic stock bits.
> 
> For the average case of the os* functions that generate dynamic
> textures, the savings would be quite high.  Typically the images created
> in textures end up being the same between iterations.
> 
>     -Sean
> 
> 
> 
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