private String readLeaderElectionId()

in src/main/java/org/apache/sling/discovery/oak/cluster/ClusterReader.java [84:104]

• 13 lines of code
• 3 McCabe index (conditional complexity)

    private String readLeaderElectionId(String slingId) {
        if (slingId==null) {
            throw new IllegalStateException("slingId must not be null");
        }
        final String myClusterNodePath = config.getClusterInstancesPath()+"/"+slingId;
        // SLING-6924 case 1 : /var/discovery/oak/clusterInstances/<slingId> can be non existant == null
        final Resource myClusterNode = resourceResolver.getResource(myClusterNodePath);
        if (myClusterNode == null) {
            // SLING-6924 : return null case 1
            return null;
        }
        ValueMap resourceMap = myClusterNode.adaptTo(ValueMap.class);
        // SLING-6924 case 2 : /var/discovery/oak/clusterInstances/<slingId> can exist BUT leaderElectionId not yet set
        //    namely the "leaderElectionId" is only written when resetLeaderElectionId() is called - which happens
        //    on OakViewChecker.activate (or when isolated) - and this activate *can* happen after properties
        //    or announcements have been written - those end up below /var/discovery/oak/clusterInstances/<slingId>/
        String result = resourceMap.get("leaderElectionId", String.class);

        // SLING-6924 : return null case 2 (if leaderElectionId is indeed null, that is)
        return result;
    }