W3C home > Mailing lists > Public > ietf-http-wg@w3.org > October to December 2002

weak entity tags vs Apache moddav

From: Julian Reschke <julian.reschke@gmx.de>
Date: Thu, 14 Nov 2002 13:26:31 +0100
To: <ietf-http-wg@w3.org>
Message-ID: <JIEGINCHMLABHJBIGKBCOEKMFMAA.julian.reschke@gmx.de>


In section 3.11 [1], RFC2616 states:

"A "weak entity tag," indicated by the "W/" prefix, MAY be shared by two
entities of a resource only if the entities are equivalent and could be
substituted for each other with no significant change in semantics. A weak
entity tag can only be used for weak comparison."

In 13.3.3 [2], it gives the following example:

"An entity's modification time, if represented with one-second resolution,
could be a weak validator, since it is possible that the resource might be
modified twice during a single second."

Apache moddav indeed returns weak entity tags based on a filesystem
timestamp. However, as far as I understand there's no guarantee whatsoever
that two entities written within one second indeed can "be substituted for
each other with no significant change in semantics". So is this a bug or am
I missing something important?


[1] <http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.3.11>
[2] <http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.13.3.3>

<green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760
Received on Thursday, 14 November 2002 07:27:03 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 11:10:36 UTC