Re: Partial Puts

Yaron Goland (yarong@microsoft.com)
Fri, 21 Mar 1997 12:04:22 -0800


Message-ID: <11352BDEEB92CF119F3F00805F14F485026B722A@RED-44-MSG.dns.microsoft.com>
From: Yaron Goland <yarong@microsoft.com>
To: "'Gregory J. Woodhouse'" <gjw@wnetc.com>
Cc: "'masinter@parc.xerox.com'" <masinter@parc.xerox.com>,
Subject: RE: Partial Puts
Date: Fri, 21 Mar 1997 12:04:22 -0800

Gregory, given this post and my response to Larry's original post, can I
assume we are in violate agreement about how to proceed with partial
PUT?
	Yaron

> -----Original Message-----
> From:	Gregory J. Woodhouse [SMTP:gjw@wnetc.com]
> Sent:	Friday, March 21, 1997 8:50 AM
> To:	Yaron Goland
> Cc:	'masinter@parc.xerox.com'; w3c-dist-auth@w3.org
> Subject:	RE: Partial Puts
> 
> I agree with Yaron that this is important functionality (though maybe
> not
> essential), and I believe it will only become more important.
> 
> I don't see any way to consolidate insert and overwrite without
> overloading
> the byte range simply because we have no notation for byte range of
> length
> 0. 
> 
> I understand Larry's concern about the resource/entity distinction,
> but I
> fail to see why the fundamental issue is any different with partial
> PUTs
> (as opposed to ordinary PUTs).
> 
> Partial PUTs are *much* more sensitive than ordinary PUTs to the
> current
> state of the resource. If the client has out of date information the
> end
> result will likely be garbled data. Therefore, I suggest a partial PUT
> include an optional (but strongly recommended) tag (in If-Match) and
> return failure if the tag is out of date. The client can then do a GET
> and
> try again with an updated partial PUT request. This may be preferable
> to a
> lock  so long as the assumption that PUTs are relatively rare holds.
> 
> I'm not sure if a new method is needed, we could just add appropriate
> request headers.
> 
> Because of the potentially disastrous consequences of interpreting a
> partial PUT as an ordinary one, PEP negotiation of this functionality
> should be mandatory.
> 
> 
> ---
> gjw@wnetc.com    /    http://www.wnetc.com/home.html
> If you're going to reinvent the wheel, at least try to come
> up with a better one.