Re: [xmlblaster] Querying Qos with XPath ?

[Cyrille Giquello <cyrille at ktaland.com>]

Marcel Ruff a écrit :

> Cyrille Giquello wrote:
> > again on da line,
> >
> > I try, but can't querying the Qos with XPath ...
> > Perhaps it's my Query, or querying Qos is not supported ???
> >
> > XPath Query = /xmlBlaster/qos/sender['test']
> >
> > Qos of message =
> > <qos>
> >    <state> OK </state>
> >    <sender> test </sender>
> >    <rcvTimestamp millis=\'1013695176202\'>2002-02-14 14:59:36.202</rcvTimestamp>
> >    <expiration timeToLive=\'129599762\'/>
> > </qos>
>
> Query of QoS with XPath is not possible.
> I even never thought of such a use case.
>
> Hmm, is this a feature we should have?

For example, my need is to select messages from "/xmlBlaster/qos/user".

No problem, I can repeat the user info in the <key ...><user>test</user></key>.

Thanx Marcel,
and forget that TODO
;o)

Cyrille

>
>
> I see some performance problems with QoS query.
> The QoS timestamp changes with every message published,
> this would force an update of the big DOM tree inside xmlBlaster
> for every publish().
>
> If i look at a typical qos:
>
>      <qos>
>         <sender>joe</sender>
>         <rcvTimestamp millis='1013695176202'/>
>         <expiration timeToLive='12000' />
>         <isVolatile>false</isVolatile>
>         <isDurable>true</isDurable>
>         <forceUpdate>true</forceUpdate>
>         <readonly>true</readonly>
>      </qos>
>
> it could be an approach to merge only more or less invariant
> tags into the bigDom....
>
> You should probably better put all queryable meta informations
> into the key.
> This will work with the current version.
>
> Marcel
>
> --
> Marcel Ruff
> mailto:ruff at swand.lake.de
> http://www.lake.de/home/lake/swand/
> http://www.xmlBlaster.org

--
 Cyrille / Ktaland

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