Thanks Santiago, I believe the Observer pattern to be a good choice.
The old system never really worked for me, there's either a bug in expire()
or its too complicated for my feeble mind...
Anyway, Im very glad to hear you are working on a new impl.
Im now discussing how the new system will work, please excuse me if Im being
redundant, but I really want to understand how this works!
How will the cache determine when a file is modified on the file system?
Will it run a daemon, which will periodically poll the file system and check
the modified date?
Or is this controlled by the expire method() - is the expire method used to
set the polling frequency?
Alternatively, I assume this can be done by someone 'deploying' an updated
file, and then calling the refresh() method
> You should think of the disk cache as URLManager, or ResourceManager. It
> is on
> charge of synchronising fetching and caching of external resources, more
> or
> less like what a HTTP proxy would do.
when you say caching, where is the caching occurring? Is the DiskCache also
for resources on other html servers?
I thought it was only for local files. If its for local files, what exactly
is being cached if it doesn't use a memory cache?
> The portlet used a memory cache, so your portlet should be cached in
> memory,
> until it expires. Once it expires, it will be reinstantiated. Look at
> the
> code in PortletFactory.
yes, i need to look at this.
Im not quite sure of the purpose of expiring portlets
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Santiago Gala
> Sent: Tuesday, January 09, 2001 5:55 PM
> To: JetSpeed
> Subject: RE: XSLPortlet , JetspeedContent
>
>
> David Sean Taylor escribió:
>
>
> I'll send it CC to the list, with the old subject, so that the answer is
> public and other people can contribute.
>
> > Hi Santiago,
> >
> > I think you may have missed my email yesterday on the mailing
> list, so Im
> > including it again below.
> > Hope you don't mind me asking you directly, but I often do not receive
> > responses to threads that I start on the mailing list, for what
> reasons I
> > really dont know.
> >
>
> I was waiting until now, that I'm back in the office, to answer. This
> time I
> even flagged it to make sure I would remember,
>
> >
> > On a more serious subject :), I believe that you and I have broken the
> > build.
> > On your part, NewRSSPortlet uses the JetspeedXMLReaderFactory, which was
> > deleted.
> >
>
> It seems that I forgot to commit this one. I have just done it. Sorry
> aboutthat one :-(
>
>
>
> >
> > Here is the email from yesterday:
> >
> > "
> > Santiago, could you help me in understanding how the DiskCache works?
> > What I'd like to do is cache content in memory, but when the resource
> > changes on the disk, then refresh it.
>
> With the old cache, entries are checked only when the DiskCacheDaemon
> runs.
> The method "hasExpired" for a cache entry tells wether it has expired,
> and
> something like:
>
> URLFetcher.refresh( url ) should try to refresh (in the same thread)
> and
> return true, if it got refreshed, or false, if either it was not expired
> or
> there was some problem, or it was not modified in the server.
>
> The whole interface is changing. For the new version, I am implementing
> the
> cache entries as java.util.Observable, so that any object can declare
> itself
> as an observer of the entry, and be notified either when it expires or
> when it
> gets refreshed. Also, the entries will have a refresh method that will
> handle
> the refresh, if needed.
>
> I'm using Observable for tests, but we can change this class by some
> other
> interface if needed after the concept is tested. I will look for similar
> patterns in Turbine/Avalon code.
>
> >
> > Like the XSLPortlet. To optimize its performance it shouldn't
> have to run
> > the transform everytime.
> > Is caching content something that the DiskCache should be providing, or
> > should we be writing that code in our portlets (like the XSLPortlet)?
> >
> > Or for a simple html file. Is the DiskCache supposed to cache
> the file in
> > memory, and then figure out when its been modified and keep the
> memory copy
> > sychronized?
>
> The actual disk cache does not handle caching in memory. For what you
> want, we
> should probably have a "glue" object that contains the object, caches
> itself
> in memory using the memory cache, and takes care of the interaction with
> the
> disk cache.
>
> The portlet used a memory cache, so your portlet should be cached in
> memory,
> until it expires. Once it expires, it will be reinstantiated. Look at
> the
> code in PortletFactory.
>
> You should think of the disk cache as URLManager, or ResourceManager. It
> is on
> charge of synchronising fetching and caching of external resources, more
> or
> less like what a HTTP proxy would do.
>
> I think that the portlet expiration mechanism has some flaws, and
> possibly
> also the Disk Cache.
>
> I don't look at it very much, since the code is very messy and I'm
> working in
> a replacement. It has to be ready "real soon now". :-)
>
> >
> > "
> >
> > Thanks,
> >
> > David
>
>
> --
> --------------------------------------------------------------
> To subscribe: [EMAIL PROTECTED]
> To unsubscribe: [EMAIL PROTECTED]
> Search: <http://www.mail-archive.com/[email protected]/>
> List Help?: [EMAIL PROTECTED]
>
>
--
--------------------------------------------------------------
To subscribe: [EMAIL PROTECTED]
To unsubscribe: [EMAIL PROTECTED]
Search: <http://www.mail-archive.com/[email protected]/>
List Help?: [EMAIL PROTECTED]
