[Zope] Cacheing

Ross J. Reedstrom reedstrm@wallace.ece.rice.edu
Tue, 14 Sep 1999 15:30:14 -0500


On Tue, Sep 14, 1999 at 02:24:21PM -0500, Evan Simpson wrote:
> Jason Jones wrote:
> 
> > From: Peter Sabaini <cccp@oeh.tu-graz.ac.at>
> 
> [snip]
> 
> > > On Tue, 14 Sep 1999, Jason Jones wrote:
> > >
> > > :As I understand it, this scheme would pretty much create a cached copy of
> > > :the rendered object which would itself live in the ZODB.
> 
> Not in the ZODB -- in memory.  The ZCache object would, of course, live
> in the ZODB and be demand loaded and unloaded like any other object.
> The actual cached text would be stored in a transient variable,
> and would evaporate if the ZCache object were unloaded.  This is
> good, since Zope will only unload it if it's taking up space that
> more popular objects need (unless rendering the object is **very**
> expensive; what then?).

Then you fall back to the case we have now: the developer does 'ad hoc'
caching, like the XML->DTML render someone else mentioned. If generating
the rendered version is **very** expensive, it should live in it's own
object in the ZODB. The developer can make her own 'rerender this object'
method. I think it falls into the same class as caching at page boundries:
nice but not compelling. 

Personally, I can't think of an example of an object that would be _that_
expensive to render: What sort of thing are you envisioning in that catagory,
that wouldn't already be represented as it's own object?

Ross
-- 
Ross J. Reedstrom, Ph.D., <reedstrm@rice.edu> 
NSBRI Research Scientist/Programmer
Computer and Information Technology Institute
Rice University, 6100 S. Main St.,  Houston, TX 77005