[OAK-11187] Implement NodeImpl.getParentOrNull

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.72.0
• Component/s: core, jackrabbit-api
• Assignee: Joerg Hoh
• Reporter: Joerg Hoh
• Created: 11/Oct/24 15:33
• Updated: 14/Nov/24 07:44
• Resolved: 15/Oct/24 12:00

Description

The JackrabbitSession already has an default implementation of

default Node getParentOrNull(@NotNull Item item) throws RepositoryException 

but internally there is no optimized version available. This can be useful, as I have seen cases in threaddumps, where the Node.getParent() implementation creates an AccessDeniedException; so there is definitely some value in an implementation of getParentOrNull in the JR extensions which avoids the creation of such an exception.

I have here a series of threaddumps, and of the 35 instances of JackrabbitSesion.getParentOrNull() 22 look like this:

        at java.lang.Throwable.fillInStackTrace(java.base@11.0.23/Native Method)
        at java.lang.Throwable.fillInStackTrace(java.base@11.0.23/Throwable.java:787)
        - locked <0x00000007300d7860> (a javax.jcr.AccessDeniedException)
        at java.lang.Throwable.<init>(java.base@11.0.23/Throwable.java:255)
        at java.lang.Exception.<init>(java.base@11.0.23/Exception.java:54)
        at javax.jcr.RepositoryException.<init>(RepositoryException.java:17)
        at javax.jcr.security.AccessControlException.<init>(AccessControlException.java:21)
        at javax.jcr.AccessDeniedException.<init>(AccessDeniedException.java:17)
        at org.apache.jackrabbit.oak.jcr.session.NodeImpl$1.perform(NodeImpl.java:195)
        at org.apache.jackrabbit.oak.jcr.session.NodeImpl$1.perform(NodeImpl.java:186)
        at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.perform(SessionDelegate.java:229)
        at org.apache.jackrabbit.oak.jcr.session.ItemImpl.perform(ItemImpl.java:113)
        at org.apache.jackrabbit.oak.jcr.session.NodeImpl.getParent(NodeImpl.java:186)
        at org.apache.jackrabbit.api.JackrabbitSession.getParentOrNull(JackrabbitSession.java:272)
        at org.apache.sling.jcr.resource.internal.helper.jcr.JcrItemResourceFactory.getParentOrNull(JcrItemResourceFactory.java:218)

For that reason I think that in the cases where getParent() either hits the root node or a non-accessible parent node, the performance penalty of the exception is quite high.

Issue Links

• relates to: OAK-11200 Make JackrabbitSession.getParentOrNull() use JackrabbitNode.getParentOrNull
• links to: GitHub Pull Request #1781