[Opensource] configuring the cache

[Michael Rimov]

At 08:12 PM 9/16/2002 +0000, you wrote:
>Hi,
>
>I have some question regarding the cache.
>1) Is there any doc available about using the expresso's caching in the 
>best way? Some sample would be great. This is one of the most powerfull 
>features of the framework and I think that some elaboration in expresso's 
>doc will be great.

No, but check out the test cases under Cache Manager as it shows simple 
caches, but it doesn't get very deep into things such as 
TTL.  SecuredDBObject is also a fine example of Caching.  But other than 
Javadocs, I'm not sure how to help you.


>2) I saw that you have a field "cachesize" in the DBOBJLIMIT table. I 
>guess that this is to indicate what is the maximum instances for a 
>particular cache item.

Yes, although it's only SPECIFICALLY used by DBObjects for a setup way of 
tweaking per DBObject cache sizes.  You will have to set the cache size 
yourself... perhaps a setup value for your custom cache.


>Well I am trying to utilize the cache by creating so cache instances by 
>myself and I was wondering how to set the number of instances for my cache 
>item. Basically I am creating a cache entry for a Vector.

One minor thing for future compatability.  Change CacheManger.<methodName> to:
CacheManger.getInstance().<methodName>  The static methods are eventually 
going to be removed.

ex:
>if (!CacheManager.existsCache(getDBName(), cacheName)) {
>          CacheManager.createCache(getDBName(), cacheName, true);
>      }
>      Vector myValues = CacheManager.getItems(getDBName(), cacheName);
>      if (myValues == null) {
>          myValues = getComboValuesNoCache(style);
>          CacheManager.setItems(getDBName(), cacheName, myValues);
>      }

Aside from the minor quibble listed above, what you're writing seems to be 
correct. [BTW, the quibble is only for Expresso 4.1 on]

HTH!
                                                 -Mike