[SLING-12217] Reduce resource lookups in Sling Model resolution

• Type: Task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Models Implementation 1.6.4
• Component/s: Sling Models
• Assignee: Unassigned
• Reporter: Joerg Hoh
• Created: 02/Jan/24 21:56
• Updated: 05/Feb/24 10:43

Description

While analyzing repository access, I found a pattern in the Scripting HTL implementation, which leads to multiple invocations of the same check on the same resources in the Sling Model ModelAdapterFactory.

Invocation at JavaUseProvider.loadObject():

• modelAdapterFactory.canCreateModelFromAdaptable()
• modelAdapterFactory.createModel

those methods directly or indirectly call org.apache.sling.models.impl.AdapterImplementations.lookup(), which calls getModelClassForResource; and there multiple resources are resolved, based on the provided resourceType.

I benchmarked this code using a simple AEM sample page (WKND) using HTL and Sling Models. I found this code is responsible to the creation of 712 JCR Node resource objects (the total page rendering triggered the creation of more than 10k, so these are around 7%). When deduplicating the requested paths, I found that only 36 distinct paths were resolved with these 712 JCR Node resources.

That means that with proper caching (probably using the ResourceResolver.getPropertyMap) around 6.5% of repository access could be avoided, leading to a page rendering improvement in about the same range.