Next message: Geoffrey M. Clemm: "Re: draft-ietf-deltav04.5 now available"
Date: Tue, 09 May 2000 08:17:11 -0700
From: Dan Kegel <dank@alumni.caltech.edu>
To: "Geoffrey M. Clemm" <geoffrey.clemm@rational.com>
Cc: ietf-dav-versioning@w3.org
Message-id: <39182BF7.A9574A36@alumni.caltech.edu>
Subject: Re: Three questions, and a paean to Perforce
Geoff, thanks for your answers!
"Geoffrey M. Clemm" wrote:
> The main reason file-based CM systems use the filesystem namespace for
> both the data being versioned and the workspaces that determine the
> version selection is that it is the only namespace they have. In
> contrast, the headers provided by HTTP provide a mechanism for
> separately specifying the versioned resource and the workspace of a
> request. In particular, the request-URL is the versioned resource and
> a Workspace header specifies the workspace.
>
> This has the advantage that absolute references (which are very common
> in href's) continue to work in the presence of versioning.
I'll take your word for it for now.
> On the other hand, there is an advantage to versioning unaware clients
> to let them see the contents of a workspace "under" that workspace,
> since a versioning-unaware client does not know how to use the
> Workspace header.
Yes. It is handy, for instance, to export an entire Perforce tree
via https. That way, plain old web browsers can use absolute URLs
to refer to file foo.c in branch 1.2 of collection foo as
https://hostname/prefix/foo/1.2/bar.c
and to file foo in the mainline (i.e. the as-yet-unbranched) collection foo as
https://hostname/prefix/foo/mainline/bar.c
> I have therefore added this to the "issue list" (it appeared on the
> agenda for this weeks phone call). In particular, I propose that
> a workspace resource be modelled as a collection resource, and that
> the "contents" of a workspace can appear as members of that workspace.
Can you illustrate how one might export a version tree via plain old
http with your proposal (since I don't quite grok delta-v lingo yet)?
> For instance, if I want to branch the collection of documents under
> ks/dev, and call the new branch 1.1, I give a command that copies
> all files under ks/dev to the new area ks/1.1. Version ids of
> the new files under ks/1.1 start from #1.
>
> In the versioning protocol, this would be marshalled as a
>
> MKWORKSPACE /ks/1.1
>
> MERGE /ks/dev
> Workspace: /ks/1.1
OK. I should put together a list of the Perforce operations I'd
like to map, and the delta-v they map to.
> 3. I notice that Christopher Seiwald (seiwald@perforce.com)
> was a frequent contributer to this list several years ago.
> Is anyone from Perforce currently represented here?
>
> Not that I know of, but if nobody shows up by final call,
> I definitely plan on giving Chris a personal call myself.
Thanks. It'd be real nice to have buyin from those folks.
- Dan
--
Entia non sunt multiplicanda praeter necessitatem.