Dan Haywood created ISIS-1283:
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Summary: SAFE_AND_CACHEABLE semantics caches incorrectly, works
for domain services (stateless) but not for domain entities (where stateful
target determines result)
Key: ISIS-1283
URL: https://issues.apache.org/jira/browse/ISIS-1283
Project: Isis
Issue Type: Bug
Components: Core
Affects Versions: 1.10.0
Reporter: Dan Haywood
Assignee: Dan Haywood
Priority: Critical
Fix For: 1.11.0
>From Oscar, on mailing list:
I’m experiencing a bad behavior using SAFE_AND_CACHEABLE actions implemented on
Domain Entities.
As current QueryResultsCache implementation has as its Key the calling class,
instead of the concrete domain entity that has invoked it, it will return the
cached result when invoking the same action on different domain objects.
For example, I have the following action:
public class Product {
// {{ findStockForSupplier (action)
@Action(semantics = SemanticsOf.SAFE_AND_REQUEST_CACHEABLE)
@ActionLayout(hidden = Where.ANYWHERE)
@MemberOrder(name = "supplierTerms", sequence = "3")
public BigDecimal findStockForSupplier(
final Supplier supplier) {
final ProductSupplierTerms productSupplierTerms =
this.wrapSkipRules(this).findTermsForSupplier(supplier);
return productSupplierTerms != null ? productSupplierTerms.getStock() :
BigDecimal.ZERO;
}
}
If I invoke that action over 2 different Products (ie, Product instances) as
per:
final ProductSupplierTerms productSupplierTerms1 =
this.wrapSkipRules(product1).findTermsForSupplier(supplier);
final ProductSupplierTerms productSupplierTerms2 =
this.wrapSkipRules(product2).findTermsForSupplier(supplier);
For the second invocation it will return the cached result, as only the class
is considered on the QueryResultsCache and not the instance “identity”, and
both “product1” and “product2” are Product instances.
As all Domain Entities implement the Comparable interface, perhaps it might be
considered.
Until now, I didn’t noticed this because I always used the QueryResultsCache
for Domain Services, and they have only 1 instance in production.
But it’s not the same when the SAFE_AND_CACHEABLE actions are implemented on
Domain Entities.
Perhaps the solution would be to simply change the QueryResultsCache.Key
implementation to accept an Object instead of a Class, using the “Comparable”
interface if implemented to differentiate between objects (for Domain Objects),
and the “equal” operator when not present (for Services)?
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