[SLING-5041] Clarify the order of the iterator given by RankedServices

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Commons OSGi 2.3.0
• Fix Version/s: Commons OSGi 2.4.0
• Component/s: Commons
• Assignee: Konrad Windszus
• Reporter: Konrad Windszus
• Created: 17/Sep/15 15:36
• Updated: 18/Jul/16 16:47
• Resolved: 26/Dec/15 13:37

Description

Currently the iterator in RankedServices returns the services in the ascending order from lowest to highest ranking. This is a different order then being used by OSGi internally [1]. Usually you are only interested in an iterator which gives you the service with the highest ranking first (because that would also be the one being returned by BundleContext.getServiceReference(...)).

If we don't change the iterator logic we should at least make it clearer in the Javadoc that the iterator really gives the services in ascending order of their service ranking property and we should probably add a more useful iterator which gives back the services with the highest ranking first.

The issue came up in the context of SLING-5035.

[1] - https://osgi.org/javadoc/r4v42/org/osgi/framework/BundleContext.html#getServiceReference(java.lang.String)

Issue Links

• is related to: SLING-5667 MockBundleContext.getServiceReference(...) does not return service reference with highest ranking
• is related to: SLING-5865 Models Impl: Update to org.apache.sling.commons.osgi 2.4.0
• is related to: SLING-5864 i18n: Update to org.apache.sling.commons.osgi 2.4.0
• relates to: SLING-5035 Sling Models Injectors should be queried in the reverse order of their service ranking value
• relates to: SLING-4521 Commons OSGi: Add helper class for thread-safe access list of ranked service dependencies