[tahoe-dev] [cap-talk] Sharing Tahoe file system directories? Loops, lost objects, etc.

[Norman Hardy]

On 2008 Apr 15, at 14:08 , Jed Donnelley wrote:

> Why would I want a shallow read-only directory capability?  One  
> example
> is to manage a project with other colleagues who I trust with write
> access to some of the underlying objects.  I can manage the project by
> choosing what to put into the shallow read-only directory (including
> whether some of the pieces are writable, shallow read-only, or deep
> read-only capabilities to directories) - nobody who I give it to can
> modify it - but everybody who I give the shallow read-only capability
> to can extract what's in it and write to that which I choose to share
> write access.

Keykos provides a RO key to a node (cap page).
It was seldom used but there was at least one important use.
Each yield of a particular factory would have a RO key to the node of  
holes for that factory.
(See http://cap-lore.com/CapTheory/KK/Factory.html for factories and  
holes.)
Had the yields had a write key to the node they would not have  
isolated from each other.
A hole is a key found in that node which has been vetted to be trusted  
to be held and shared among yields of this factory.