private void doUpdateProperties()

in src/main/java/org/apache/sling/discovery/oak/OakDiscoveryService.java [481:565]
66 lines of code
16 McCabe index (conditional complexity)

    private void doUpdateProperties() {
        // SLING-5382 : the caller must ensure that this method
        // is not invoked after deactivation or before activation.
        // so this method doesn't have to do any further synchronization.
        // what we do nevertheless is a paranoia way of checking if
        // all variables are available and do a NOOP if that's not the case.
        final ResourceResolverFactory rrf = resourceResolverFactory;
        final Config c = config;
        final String sid = slingId;
        if (rrf == null || c == null || sid == null) {
            // cannot update the properties then..
            logger.debug("doUpdateProperties: too early to update the properties. "
                            + "resourceResolverFactory ({}), config ({}) or slingId ({}) not yet set.",
                    new Object[]{rrf, c, sid});
            return;
        } else {
            logger.debug("doUpdateProperties: updating properties now..");
        }

        final Map<String, String> newProps = new HashMap<>();
        for (final ProviderInfo info : this.providerInfos) {
            info.refreshProperties();
            newProps.putAll(info.properties);
        }

        ResourceResolver resourceResolver = null;
        try {
            resourceResolver = rrf.getServiceResourceResolver(null);

            Resource myInstance = ResourceHelper
                    .getOrCreateResource(resourceResolver, c.getClusterInstancesPath() + "/" + sid + "/properties");
            // SLING-2879 - revert/refresh resourceResolver here to work
            // around a potential issue with jackrabbit in a clustered environment
            resourceResolver.revert();
            resourceResolver.refresh();

            final ModifiableValueMap myInstanceMap = myInstance.adaptTo(ModifiableValueMap.class);
            final Set<String> keys = new HashSet<String>(myInstanceMap.keySet());
            for (final String key : keys) {
                if (newProps.containsKey(key)) {
                    // perfect
                    continue;
                } else if (key.indexOf(":") != -1) {
                    // ignore
                    continue;
                } else {
                    // remove
                    myInstanceMap.remove(key);
                }
            }

            boolean anyChanges = false;
            for (final Entry<String, String> entry : newProps.entrySet()) {
                Object existingValue = myInstanceMap.get(entry.getKey());
                if (entry.getValue().equals(existingValue)) {
                    // SLING-3389: dont rewrite the properties if nothing changed!
                    if (logger.isDebugEnabled()) {
                        logger.debug("doUpdateProperties: unchanged: {}={}", entry.getKey(), entry.getValue());
                    }
                    continue;
                }
                if (logger.isDebugEnabled()) {
                    logger.debug("doUpdateProperties: changed: {}={}", entry.getKey(), entry.getValue());
                }
                anyChanges = true;
                myInstanceMap.put(entry.getKey(), entry.getValue());
            }

            if (anyChanges) {
                resourceResolver.commit();
            }
        } catch (LoginException e) {
            logger.error("handleEvent: could not log in administratively: " + e, e);
            throw new RuntimeException("Could not log in to repository (" + e + ")", e);
        } catch (PersistenceException e) {
            logger.error("handleEvent: got a PersistenceException: " + e, e);
            throw new RuntimeException( "Exception while talking to repository (" + e + ")", e);
        } finally {
            if (resourceResolver != null) {
                resourceResolver.close();
            }
        }

        logger.debug("doUpdateProperties: updating properties done.");
    }