public synchronized String toSlingId()

in src/main/java/org/apache/sling/discovery/commons/providers/spi/base/IdMapService.java [260:299]
28 lines of code
9 McCabe index (conditional complexity)

    public synchronized String toSlingId(int clusterNodeId, ResourceResolver resourceResolver) throws PersistenceException {
        if (System.currentTimeMillis() - lastCacheInvalidation > 30000) {
            // since upon a restart of an instance it could opt to have changed
            // the slingId, we might not be able to catch that change if we
            // noticed the view change before that (the view change would
            // force a cache invalidation).
            // we can either rely on observation - or combine that with
            // an invalidation of once per minute
            // (note that this means we'll be reading
            // /var/discovery/oak/idMap once per minute - but that sounds
            // perfectly fine)
            clearCache();
        }
        String slingId = idMapCache.get(clusterNodeId);
        if (slingId!=null) {
            // cache-hit
            return slingId;
        }
        // cache-miss
        logger.debug("toSlingId: cache miss, refreshing idmap cache");
        Map<Integer, String> readMap = readIdMap(resourceResolver);
        Set<Entry<Integer, String>> newEntries = readMap.entrySet();
        for (Entry<Integer, String> newEntry : newEntries) {
            String oldValue = oldIdMapCache.get(newEntry.getKey());
            if (oldValue == null || !oldValue.equals(newEntry.getValue())) {
                logger.info("toSlingId: mapping for "+newEntry.getKey()+" to "+newEntry.getValue() + " was newly added.");
            } else if (!oldValue.equals(newEntry.getValue())) {
                logger.info("toSlingId: mapping for "+newEntry.getKey()+" changed from "+oldValue+" to "+newEntry.getValue());
            }
            idMapCache.put(newEntry.getKey(), newEntry.getValue());
        }
        Set<Entry<Integer, String>> oldEntries = oldIdMapCache.entrySet();
        for (Entry<Integer, String> oldEntry : oldEntries) {
            if (!idMapCache.containsKey(oldEntry.getKey())) {
                logger.info("toSlingId: mapping for "+oldEntry.getKey()+" to "+oldEntry.getValue()+" disappeared.");
            }
        }

        return idMapCache.get(clusterNodeId);
    }