CacheStateManager

I have resolved the problem. Turns out using ExecuteQueryAsync for both the initial query and against the restored cache does not work. I switched to using ExecuteQuery for the restored cached instance and now all objects are being returned

I may have spoken too quickly on this matter. Here is what I am trying to accomplish

I'm a little confused about what the exact issues are at this point.  If I understand you, you want to be able, during an application session, to save some collection of cache contents to a local EntityState disk file. At app startup (or some other time), you will load data from the disk file if there is one; otherwise, you'll load the same collection of data from the database.

You say that if you load from the database you can query the EntityManager's cache successfully; but if you load from the local EntityState file you can't? That doesn't make a lot of sense to me as is, because the state of the EntityManager cache is the state of the EntityManager cache, no matter how it got to that state; and if the entities you want are there, they're there, no matter how they got there. So there must be something else going on. How exactly does GetAll() go about asking for the data it wants?

To answer your other question: an EntityManager cache can be converted to an EntityCacheState object which is serializable. So you can populate an EntityManager's cache in a server-side method that returns an EntityCacheState object populated from that server-side EM. Then client-side you can import the EntityCacheState contents into the cache managed by the client-side EntityManager.


Edited by GregD - 19-Oct-2009 at 5:44pm

ok, have resolved the problem. Turns out to be PEBKAC ( Problem Exists Between Keyboard And Chair ). I had a separate entity manager which had a reference to the EntityManager from the main class. Turns out I was creating the EntityManager class and setting it's local EM to a version of the EM before I restored it from Cache so of course none of the Entities were available. I have since modified the code to make sure I pass in an updated EM anytime I restore from cache or refresh it with any new objects. Thanks

I found a solution, but still with an error, use. With (QueryStrategy.CacheOnly) and ran to fetch only the entities in the cache, but my second problem is that the IEntityQuery used for the search is based on a PassthruEsqlQuery.

TheDynamicTypeVar is a variable of type Type. (Type of entity basis)

This does not work: (error: Must Be FetchStrategy is PassthruEsqlQuery DatasourceOnly)
new PassthruEsqlQuery (TheDynamicTypeVar, "SELECT VALUE FROM YOU AS TheEntitySetName TE). With (QueryStrategy.CacheOnly);

This would work (not possible in my implementation):

query = new EntityQuery <T> (InstanceOfTheDynamicType.EntityAspect.EntitySetName, MyEntityManager). With (QueryStrategy.CacheOnly);

It also:

query = new EntityQuery <MyEntityType> (InstanceOfTheDynamicType.EntityAspect.EntitySetName, MyEntityManager). With (QueryStrategy.CacheOnly);

Already this does NOT work:

query = new EntityQuery <TheDynamicTypeVar> (InstanceOfTheDynamicType.EntityAspect.EntitySetName, MyEntityManager). With (QueryStrategy.CacheOnly);

Using a variable (TheDynamicTypeVar) to replace the generic type T in new EntityQuery <T>?

Thank you.