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RE: Locks and loopback bindings

From: Jim Whitehead <ejw@cs.ucsc.edu>
Date: Mon, 6 Dec 2004 09:51:06 -0800
Message-Id: <200412061751.iB6HpF9j020768@cats-mx1.ucsc.edu>
To: "'Stefan Eissing'" <stefan.eissing@greenbytes.de>
Cc: "'WebDAV \(WebDAV WG\)'" <w3c-dist-auth@w3.org>

> May I ask what the definition of a "loopback binding" is and 
> how it differs from other bindings?

A rough definition is any binding that converts an acyclic containment graph
into a cyclic graph. This is also how it differs from other bindings. 

> Some servers will require 
> acyclic graphs while others will allow cycles.

Right. In the case where servers support cycles, and also support depth
locks, they'll need to develop semantics for the interaction of these two
features. At present, the bind specification provides no guidance for this

> The set of deep-locked nodes is the set of nodes reachable 
> from the starting point. We could provide an algorithm for 
> server implementors, and even more important for clients, on 
> how to find this set and not get lost in possible cycles.

We could do this, although I'd rather not get into specifying which kind of
traversal algorithm servers should use (depth first vs breadth first, etc.),
since that's implementation detail. 

I'd rather point out that, no matter which kind of traversal you use to
compute closure, there are certain edges (loopback edges) that should not be
followed in computing the closure.

- Jim
Received on Monday, 6 December 2004 17:52:43 UTC

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