On Aug 22, 2012, at 3:04 PM, Andrus Adamchik wrote:
>> Local cache is local to a data context (right?). But currently the
>> application creates a new datacontext for every "transaction", so if I
>> understood correctly the local cache is useless and I should use the shared
>> cache.
>
> Correct.
>
>> I also tried to add a listener (on postPersist, postUpdate and postRemove)
>> to clear the cache for that particular group, but it does not work:
>>
>> private void clearCache(Object entity) {
>> Persistent object = (Persistent)entity;
>> QueryCache cache =
>> ((BaseContext)object.getObjectContext()).getQueryCache();
>> cache.removeGroup(object.getClass().getName());
>> }
>
> This is going in the right direction. So is listener method invoked, but the
> cache is not cleared, or the listener method is never invoked.
>
> BTW Cayenne 3.1 has a nice set of extensions called cayenne-lifecycle. The
> docs are still sparse (we are working on those), but there is a @CacheGroups
> annotation placed on persistent classes that tells Cayenne that any changes
> to a given type of objects should generate a cache invalidation event. E.g.:
>
> @CacheGroups("news")
> public class News extends com.foo.auto._News { }
>
> processing of this annotation is enabled by installing
> org.apache.cayenne.lifecycle.cache.CacheInvalidationFilter (also part of
> cayenne-lifecycle):
>
> DataChannelFilter filter = new CacheInvalidationFilter();
>
> CayenneRuntime runtime = ...
>
> // a bit clunky.. may merge the following 2 lines in one in the future
> releases:
> runtime.getDataDomain().addFilter(filter);
> runtime.getDataDomain().getEntityResolver().getCallbackRegistry().addListener(filter);
>
> Cheers,
> Andrus
>
Thank you for your answer.
I don't think we can update our cayenne right now, but we will take a look at
the annotations asap (it means: when we can spend some time to update cayenne).
This morning I think I found a solution which seems to work:
private void clearCache(Object entity) {
Persistent object = (Persistent)entity;
ObjectContext context = object.getObjectContext();
if (context instanceof DataContext) {
DataContext dataContext = (DataContext)context;
QueryCache cache =
dataContext.getParentDataDomain().getQueryCache();
cache.removeGroup(object.getClass().getName());
}
}
Is this acceptable (at least .. waiting for our update to cayenne) ?
Regards
Francesco Romano
>
> On Aug 21, 2012, at 6:36 PM, Francesco Romano wrote:
>> Hi everybody.
>>
>> I'm trying to add caching support (query cache) to a project which uses
>> cayenne.
>> For what I understood in the online documentation there are two types of
>> caches: local and shared.
>> Local cache is local to a data context (right?). But currently the
>> application creates a new datacontext for every "transaction", so if I
>> understood correctly the local cache is useless and I should use the shared
>> cache.
>>
>> Now... the problem.. I have a query cached (a sort of select * from table)
>> and a new row is added in the table. I would like that the next time the
>> same query is called also the new row is fetched.
>>
>> This is the query cache
>>
>> SelectQuery select = new SelectQuery(t);
>> Class t; //this is the class of the persistent object to be fetched
>> select.setCacheStrategy(QueryCacheStrategy.SHARED_CACHE);
>>
>> select.setCacheGroups(t.getName());
>>
>> This is my "sample" test code (Network is a Cayenne Object class)
>> (GetAllNetwork is a selectquery with the above caching. AddNetwork adds a
>> new object and commit it. A new DataContext is used every time)
>>
>> List<Network> networks = dbHandle.GetAllNetwork();
>> Network net = dbHandle.AddNetwork();
>> List<Network> newNetworks = dbHandle.GetAllNetwork();
>>
>> assertEquals(networks.size() + 1, newNetworks.size());
>>
>>
>> Now... my assert is not true, because the query is cached.
>> I also tried to add a listener (on postPersist, postUpdate and postRemove)
>> to clear the cache for that particular group, but it does not work:
>>
>> private void clearCache(Object entity) {
>> Persistent object = (Persistent)entity;
>> QueryCache cache =
>> ((BaseContext)object.getObjectContext()).getQueryCache();
>> cache.removeGroup(object.getClass().getName());
>> }
>>
>> Any help?
>>
>> Thanks
>> Regards
>>
>> Francesco Romano
>>
>
>
