security-admin/src/main/java/org/apache/ranger/common/RangerServiceTagsCache.java - ranger - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */

 package org.apache.ranger.common;

 import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.lang.StringUtils;
 import org.apache.ranger.authorization.hadoop.config.RangerAdminConfig;
 import org.apache.ranger.plugin.store.TagStore;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.ranger.plugin.util.RangerServiceTagsDeltaUtil;
 import org.apache.ranger.plugin.util.ServiceTags;

 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;

 public class RangerServiceTagsCache {
 	private static final Log LOG = LogFactory.getLog(RangerServiceTagsCache.class);

 	private static final int MAX_WAIT_TIME_FOR_UPDATE = 10;

 	private static volatile RangerServiceTagsCache sInstance = null;
 	private final boolean useServiceTagsCache;
 	private final int waitTimeInSeconds;

 	private final Map<String, ServiceTagsWrapper> serviceTagsMap = new HashMap<>();

 	public static RangerServiceTagsCache getInstance() {
 		if (sInstance == null) {
 			synchronized (RangerServiceTagsCache.class) {
 				if (sInstance == null) {
 					sInstance = new RangerServiceTagsCache();
 				}
 			}
 		}
 		return sInstance;
 	}

 	private RangerServiceTagsCache() {
 		RangerAdminConfig config = new RangerAdminConfig();

 		useServiceTagsCache = config.getBoolean("ranger.admin.tag.download.usecache", true);
 		waitTimeInSeconds   = config.getInt("ranger.admin.tag.download.cache.max.waittime.for.update", MAX_WAIT_TIME_FOR_UPDATE);
 	}

 	public void dump() {

 		if (useServiceTagsCache) {
 			final Set<String> serviceNames;

 			synchronized (this) {
 				serviceNames = serviceTagsMap.keySet();
 			}

 			if (CollectionUtils.isNotEmpty(serviceNames)) {
 				ServiceTagsWrapper cachedServiceTagsWrapper;

 				for (String serviceName : serviceNames) {
 					synchronized (this) {
 						cachedServiceTagsWrapper = serviceTagsMap.get(serviceName);
 					}
 					LOG.debug("serviceName:" + serviceName + ", Cached-MetaData:" + cachedServiceTagsWrapper);
 				}
 			}
 		}
 	}

 	public ServiceTags getServiceTags(String serviceName, Long serviceId, Long lastKnownVersion, boolean needsBackwardCompatibility, TagStore tagStore) throws Exception {

 		if (LOG.isDebugEnabled()) {
 			LOG.debug("==> RangerServiceTagsCache.getServiceTags(" + serviceName + ", " + serviceId + ", " + lastKnownVersion + ", " + needsBackwardCompatibility + ")");
 		}

 		ServiceTags ret = null;

 		if (StringUtils.isNotBlank(serviceName) && serviceId != null) {

 			if (LOG.isDebugEnabled()) {
 				LOG.debug("useServiceTagsCache=" + useServiceTagsCache);
 			}

 			if (!useServiceTagsCache) {
 				if (tagStore != null) {
 					try {
 						ret = tagStore.getServiceTags(serviceName, -1L);
 					} catch (Exception exception) {
 						LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags from tag-store", exception);
 					}
 				} else {
 					LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags as tag-store is null!");
 				}
 			} else {
 				ServiceTagsWrapper serviceTagsWrapper;

 				synchronized (this) {
 					serviceTagsWrapper = serviceTagsMap.get(serviceName);

 					if (serviceTagsWrapper != null) {
 						if (!serviceId.equals(serviceTagsWrapper.getServiceId())) {
 							if (LOG.isDebugEnabled()) {
 								LOG.debug("Service [" + serviceName + "] changed service-id from " + serviceTagsWrapper.getServiceId()
 										+ " to " + serviceId);
 								LOG.debug("Recreating serviceTagsWrapper for serviceName [" + serviceName + "]");
 							}
 							serviceTagsMap.remove(serviceName);
 							serviceTagsWrapper = null;
 						}
 					}
 					if (serviceTagsWrapper == null) {
 						serviceTagsWrapper = new ServiceTagsWrapper(serviceId);
 						serviceTagsMap.put(serviceName, serviceTagsWrapper);
 					}
 				}

 				if (tagStore != null) {
 					ret = serviceTagsWrapper.getLatestOrCached(serviceName, tagStore, lastKnownVersion, needsBackwardCompatibility);
 				} else {
 					LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags as tag-store is null!");
 					ret = serviceTagsWrapper.getServiceTags();
 				}

 			}
 		} else {
 			LOG.error("getServiceTags() failed to get tags as serviceName is null or blank and/or serviceId is null!");
 		}

 		if (LOG.isDebugEnabled()) {
 			LOG.debug("<== RangerServiceTagsCache.getServiceTags(" + serviceName + ", " + serviceId + ", " + lastKnownVersion + ", " + needsBackwardCompatibility + "): count=" + ((ret == null || ret.getTags() == null) ? 0 : ret.getTags().size()));
 		}

 		return ret;
 	}

 	private class ServiceTagsWrapper {
 		final Long serviceId;
 		ServiceTags serviceTags;
 		Date updateTime = null;
 		long longestDbLoadTimeInMs = -1;

 		ServiceTagsDeltasCache deltaCache;

 		class ServiceTagsDeltasCache {
 			final long        		fromVersion;
 			final ServiceTags 		serviceTagsDelta;

 			ServiceTagsDeltasCache(final long fromVersion, ServiceTags serviceTagsDelta) {
 				this.fromVersion         = fromVersion;
 				this.serviceTagsDelta    = serviceTagsDelta;
 			}
 			ServiceTags getServiceTagsDeltaFromVersion(long fromVersion) {
 				return this.fromVersion == fromVersion ? this.serviceTagsDelta : null;
 			}
 		}
 		ReentrantLock lock = new ReentrantLock();

 		ServiceTagsWrapper(Long serviceId) {
 			this.serviceId = serviceId;
 			serviceTags = null;
 		}

 		Long getServiceId() { return serviceId; }

 		ServiceTags getServiceTags() {
 			return serviceTags;
 		}

 		Date getUpdateTime() {
 			return updateTime;
 		}

 		ServiceTags getLatestOrCached(String serviceName, TagStore tagStore, Long lastKnownVersion, boolean needsBackwardCompatibility) throws Exception {
 			if (LOG.isDebugEnabled()) {
 				LOG.debug("==> RangerServiceTagsCache.getLatestOrCached(lastKnownVersion=" + lastKnownVersion + ", " + needsBackwardCompatibility + ")");
 			}
 			ServiceTags	ret		   = null;
 			boolean		lockResult = false;

 			try {
 				final boolean isCacheCompletelyLoaded;

 				lockResult = lock.tryLock(waitTimeInSeconds, TimeUnit.SECONDS);
 				if (lockResult) {

 					isCacheCompletelyLoaded = getLatest(serviceName, tagStore);

 					if (isCacheCompletelyLoaded) {
 						if (LOG.isDebugEnabled()) {
 							LOG.debug("ServiceTags cache was completely loaded from database ");
 						}
 					}
 					if (needsBackwardCompatibility || isCacheCompletelyLoaded
 							|| lastKnownVersion == -1L || lastKnownVersion.equals(serviceTags.getTagVersion())) {
 						// Looking for all tags, or Some disqualifying change encountered
 						if (LOG.isDebugEnabled()) {
 							LOG.debug("Need to return all cached ServiceTags: [needsBackwardCompatibility:" + needsBackwardCompatibility + ", isCacheCompletelyLoaded:" + isCacheCompletelyLoaded + ", lastKnownVersion:" + lastKnownVersion + ", serviceTagsVersion:" + serviceTags.getTagVersion() + "]");
 						}
 						ret = this.serviceTags;
 					} else {
 						boolean isDeltaCacheReinitialized = false;
 						ServiceTags serviceTagsDelta = this.deltaCache != null ? this.deltaCache.getServiceTagsDeltaFromVersion(lastKnownVersion) : null;

 						if (serviceTagsDelta == null) {
 							serviceTagsDelta = tagStore.getServiceTagsDelta(serviceName, lastKnownVersion);
 							isDeltaCacheReinitialized = true;
 						}
 						if (serviceTagsDelta != null) {
 							if (LOG.isDebugEnabled()) {
 								LOG.debug("Deltas were requested. Returning deltas from lastKnownVersion:[" + lastKnownVersion + "]");
 							}
 							if (isDeltaCacheReinitialized) {
 								this.deltaCache = new ServiceTagsDeltasCache(lastKnownVersion, serviceTagsDelta);
 							}
 							ret = serviceTagsDelta;
 						} else {
 							LOG.warn("Deltas were requested, but could not get them!! lastKnownVersion:[" + lastKnownVersion + "]; Returning cached ServiceTags:[" + (serviceTags != null ? serviceTags.getTagVersion() : -1L) + "]");

 							this.deltaCache = null;
 							ret = this.serviceTags;
 						}
 					}
 				} else {
 					if (LOG.isDebugEnabled()) {
 						LOG.debug("Could not get lock in [" + waitTimeInSeconds + "] seconds, returning cached ServiceTags");
 					}
 					ret = this.serviceTags;
 				}
 			} catch (InterruptedException exception) {
 				LOG.error("getLatestOrCached:lock got interrupted..", exception);
 			} finally {
 				if (lockResult) {
 					lock.unlock();
 				}
 			}
 			if (LOG.isDebugEnabled()) {
 				LOG.debug("<== RangerServiceTagsCache.getLatestOrCached(lastKnownVersion=" + lastKnownVersion + ", " + needsBackwardCompatibility + "): " + ret);
 			}

 			return ret;
 		}

 		boolean getLatest(String serviceName, TagStore tagStore) throws Exception {
 			if (LOG.isDebugEnabled()) {
 				LOG.debug("==> ServiceTagsWrapper.getLatest(" + serviceName + ")");
 			}

 			boolean isCacheCompletelyLoaded = false;

 			final Long cachedServiceTagsVersion = serviceTags != null ? serviceTags.getTagVersion() : -1L;

 			if (LOG.isDebugEnabled()) {
 				LOG.debug("Found ServiceTags in-cache : " + (serviceTags != null));
 			}

 			Long tagVersionInDb = tagStore.getTagVersion(serviceName);

 			if (serviceTags == null || tagVersionInDb == null || !tagVersionInDb.equals(cachedServiceTagsVersion)) {
 				if (LOG.isDebugEnabled()) {
 					LOG.debug("loading serviceTags from db ... cachedServiceTagsVersion=" + cachedServiceTagsVersion + ", tagVersionInDb=" + tagVersionInDb);
 				}

 				long startTimeMs = System.currentTimeMillis();

 				ServiceTags serviceTagsFromDb = tagStore.getServiceTags(serviceName, cachedServiceTagsVersion);

 				long dbLoadTime = System.currentTimeMillis() - startTimeMs;

 				if (dbLoadTime > longestDbLoadTimeInMs) {
 					longestDbLoadTimeInMs = dbLoadTime;
 				}
 				updateTime = new Date();

 				if (serviceTagsFromDb != null) {
 					if (serviceTags == null) {
 						if (LOG.isDebugEnabled()) {
 							LOG.debug("Initializing ServiceTags cache for the first time");
 						}
 						serviceTags = serviceTagsFromDb;
 						this.deltaCache = null;
 						pruneUnusedAttributes();
 						isCacheCompletelyLoaded = true;
 					} else if (!serviceTagsFromDb.getIsDelta()) {
 						// service-tags are loaded because of some disqualifying event
 						if (LOG.isDebugEnabled()) {
 							LOG.debug("Complete set of tag are loaded from database, because of some disqualifying event or because tag-delta is not supported");
 						}
 						serviceTags = serviceTagsFromDb;
 						this.deltaCache = null;
 						pruneUnusedAttributes();
 						isCacheCompletelyLoaded = true;
 					} else { // Previously cached service tags are still valid - no disqualifying change
 						// Rebuild tags cache from original tags and deltas
 						if (LOG.isDebugEnabled()) {
 							LOG.debug("Retrieved tag-deltas from database. These will be applied on top of ServiceTags version:[" + cachedServiceTagsVersion + "], tag-deltas:[" + serviceTagsFromDb.getTagVersion() + "]");
 						}
 						RangerServiceTagsDeltaUtil.applyDelta(serviceTags, serviceTagsFromDb);
 						this.deltaCache = new ServiceTagsDeltasCache(cachedServiceTagsVersion, serviceTagsFromDb);
 					}
 				} else {
 					LOG.error("Could not get tags from database, from-version:[" + cachedServiceTagsVersion + ")");
 				}
 				if (LOG.isDebugEnabled()) {
 					LOG.debug("ServiceTags old-version:[" + cachedServiceTagsVersion + "], new-version:[" + serviceTags.getTagVersion() + "]");
 				}
 			} else {
 				if (LOG.isDebugEnabled()) {
 					LOG.debug("ServiceTags Cache already has the latest version, version:[" + cachedServiceTagsVersion + "]");
 				}
 			}

 			if (LOG.isDebugEnabled()) {
 				LOG.debug("<== ServiceTagsWrapper.getLatest(" + serviceName + "): " + isCacheCompletelyLoaded);
 			}

 			return isCacheCompletelyLoaded;
 		}

 		private void pruneUnusedAttributes() {
 			RangerServiceTagsDeltaUtil.pruneUnusedAttributes(this.serviceTags);
 		}

 		StringBuilder toString(StringBuilder sb) {
 			sb.append("RangerServiceTagsWrapper={");

 			sb.append("updateTime=").append(updateTime)
 					.append(", longestDbLoadTimeInMs=").append(longestDbLoadTimeInMs)
 					.append(", Service-Version:").append(serviceTags != null ? serviceTags.getTagVersion() : "null")
 					.append(", Number-Of-Tags:").append(serviceTags != null ? serviceTags.getTags().size() : 0);

 			sb.append("} ");

 			return sb;
 		}

 		@Override
 		public String toString() {
 			StringBuilder sb = new StringBuilder();

 			toString(sb);

 			return sb.toString();
 		}
 	}
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/

	package org.apache.ranger.common;

	import org.apache.commons.collections.CollectionUtils;
	import org.apache.commons.lang.StringUtils;
	import org.apache.ranger.authorization.hadoop.config.RangerAdminConfig;
	import org.apache.ranger.plugin.store.TagStore;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.ranger.plugin.util.RangerServiceTagsDeltaUtil;
	import org.apache.ranger.plugin.util.ServiceTags;

	import java.util.Date;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Set;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.locks.ReentrantLock;

	public class RangerServiceTagsCache {
	private static final Log LOG = LogFactory.getLog(RangerServiceTagsCache.class);

	private static final int MAX_WAIT_TIME_FOR_UPDATE = 10;

	private static volatile RangerServiceTagsCache sInstance = null;
	private final boolean useServiceTagsCache;
	private final int waitTimeInSeconds;

	private final Map<String, ServiceTagsWrapper> serviceTagsMap = new HashMap<>();

	public static RangerServiceTagsCache getInstance() {
	if (sInstance == null) {
	synchronized (RangerServiceTagsCache.class) {
	if (sInstance == null) {
	sInstance = new RangerServiceTagsCache();
	}
	}
	}
	return sInstance;
	}

	private RangerServiceTagsCache() {
	RangerAdminConfig config = new RangerAdminConfig();

	useServiceTagsCache = config.getBoolean("ranger.admin.tag.download.usecache", true);
	waitTimeInSeconds = config.getInt("ranger.admin.tag.download.cache.max.waittime.for.update", MAX_WAIT_TIME_FOR_UPDATE);
	}

	public void dump() {

	if (useServiceTagsCache) {
	final Set<String> serviceNames;

	synchronized (this) {
	serviceNames = serviceTagsMap.keySet();
	}

	if (CollectionUtils.isNotEmpty(serviceNames)) {
	ServiceTagsWrapper cachedServiceTagsWrapper;

	for (String serviceName : serviceNames) {
	synchronized (this) {
	cachedServiceTagsWrapper = serviceTagsMap.get(serviceName);
	}
	LOG.debug("serviceName:" + serviceName + ", Cached-MetaData:" + cachedServiceTagsWrapper);
	}
	}
	}
	}

	public ServiceTags getServiceTags(String serviceName, Long serviceId, Long lastKnownVersion, boolean needsBackwardCompatibility, TagStore tagStore) throws Exception {

	if (LOG.isDebugEnabled()) {
	LOG.debug("==> RangerServiceTagsCache.getServiceTags(" + serviceName + ", " + serviceId + ", " + lastKnownVersion + ", " + needsBackwardCompatibility + ")");
	}

	ServiceTags ret = null;

	if (StringUtils.isNotBlank(serviceName) && serviceId != null) {

	if (LOG.isDebugEnabled()) {
	LOG.debug("useServiceTagsCache=" + useServiceTagsCache);
	}

	if (!useServiceTagsCache) {
	if (tagStore != null) {
	try {
	ret = tagStore.getServiceTags(serviceName, -1L);
	} catch (Exception exception) {
	LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags from tag-store", exception);
	}
	} else {
	LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags as tag-store is null!");
	}
	} else {
	ServiceTagsWrapper serviceTagsWrapper;

	synchronized (this) {
	serviceTagsWrapper = serviceTagsMap.get(serviceName);

	if (serviceTagsWrapper != null) {
	if (!serviceId.equals(serviceTagsWrapper.getServiceId())) {
	if (LOG.isDebugEnabled()) {
	LOG.debug("Service [" + serviceName + "] changed service-id from " + serviceTagsWrapper.getServiceId()
	+ " to " + serviceId);
	LOG.debug("Recreating serviceTagsWrapper for serviceName [" + serviceName + "]");
	}
	serviceTagsMap.remove(serviceName);
	serviceTagsWrapper = null;
	}
	}
	if (serviceTagsWrapper == null) {
	serviceTagsWrapper = new ServiceTagsWrapper(serviceId);
	serviceTagsMap.put(serviceName, serviceTagsWrapper);
	}
	}

	if (tagStore != null) {
	ret = serviceTagsWrapper.getLatestOrCached(serviceName, tagStore, lastKnownVersion, needsBackwardCompatibility);
	} else {
	LOG.error("getServiceTags(" + serviceName + "): failed to get latest tags as tag-store is null!");
	ret = serviceTagsWrapper.getServiceTags();
	}

	}
	} else {
	LOG.error("getServiceTags() failed to get tags as serviceName is null or blank and/or serviceId is null!");
	}

	if (LOG.isDebugEnabled()) {
	LOG.debug("<== RangerServiceTagsCache.getServiceTags(" + serviceName + ", " + serviceId + ", " + lastKnownVersion + ", " + needsBackwardCompatibility + "): count=" + ((ret == null \|\| ret.getTags() == null) ? 0 : ret.getTags().size()));
	}

	return ret;
	}

	private class ServiceTagsWrapper {
	final Long serviceId;
	ServiceTags serviceTags;
	Date updateTime = null;
	long longestDbLoadTimeInMs = -1;

	ServiceTagsDeltasCache deltaCache;

	class ServiceTagsDeltasCache {
	final long fromVersion;
	final ServiceTags serviceTagsDelta;

	ServiceTagsDeltasCache(final long fromVersion, ServiceTags serviceTagsDelta) {
	this.fromVersion = fromVersion;
	this.serviceTagsDelta = serviceTagsDelta;
	}
	ServiceTags getServiceTagsDeltaFromVersion(long fromVersion) {
	return this.fromVersion == fromVersion ? this.serviceTagsDelta : null;
	}
	}
	ReentrantLock lock = new ReentrantLock();

	ServiceTagsWrapper(Long serviceId) {
	this.serviceId = serviceId;
	serviceTags = null;
	}

	Long getServiceId() { return serviceId; }

	ServiceTags getServiceTags() {
	return serviceTags;
	}

	Date getUpdateTime() {
	return updateTime;
	}

	ServiceTags getLatestOrCached(String serviceName, TagStore tagStore, Long lastKnownVersion, boolean needsBackwardCompatibility) throws Exception {
	if (LOG.isDebugEnabled()) {
	LOG.debug("==> RangerServiceTagsCache.getLatestOrCached(lastKnownVersion=" + lastKnownVersion + ", " + needsBackwardCompatibility + ")");
	}
	ServiceTags ret = null;
	boolean lockResult = false;

	try {
	final boolean isCacheCompletelyLoaded;

	lockResult = lock.tryLock(waitTimeInSeconds, TimeUnit.SECONDS);
	if (lockResult) {

	isCacheCompletelyLoaded = getLatest(serviceName, tagStore);

	if (isCacheCompletelyLoaded) {
	if (LOG.isDebugEnabled()) {
	LOG.debug("ServiceTags cache was completely loaded from database ");
	}
	}
	if (needsBackwardCompatibility \|\| isCacheCompletelyLoaded
	\|\| lastKnownVersion == -1L \|\| lastKnownVersion.equals(serviceTags.getTagVersion())) {
	// Looking for all tags, or Some disqualifying change encountered
	if (LOG.isDebugEnabled()) {
	LOG.debug("Need to return all cached ServiceTags: [needsBackwardCompatibility:" + needsBackwardCompatibility + ", isCacheCompletelyLoaded:" + isCacheCompletelyLoaded + ", lastKnownVersion:" + lastKnownVersion + ", serviceTagsVersion:" + serviceTags.getTagVersion() + "]");
	}
	ret = this.serviceTags;
	} else {
	boolean isDeltaCacheReinitialized = false;
	ServiceTags serviceTagsDelta = this.deltaCache != null ? this.deltaCache.getServiceTagsDeltaFromVersion(lastKnownVersion) : null;

	if (serviceTagsDelta == null) {
	serviceTagsDelta = tagStore.getServiceTagsDelta(serviceName, lastKnownVersion);
	isDeltaCacheReinitialized = true;
	}
	if (serviceTagsDelta != null) {
	if (LOG.isDebugEnabled()) {
	LOG.debug("Deltas were requested. Returning deltas from lastKnownVersion:[" + lastKnownVersion + "]");
	}
	if (isDeltaCacheReinitialized) {
	this.deltaCache = new ServiceTagsDeltasCache(lastKnownVersion, serviceTagsDelta);
	}
	ret = serviceTagsDelta;
	} else {
	LOG.warn("Deltas were requested, but could not get them!! lastKnownVersion:[" + lastKnownVersion + "]; Returning cached ServiceTags:[" + (serviceTags != null ? serviceTags.getTagVersion() : -1L) + "]");

	this.deltaCache = null;
	ret = this.serviceTags;
	}
	}
	} else {
	if (LOG.isDebugEnabled()) {
	LOG.debug("Could not get lock in [" + waitTimeInSeconds + "] seconds, returning cached ServiceTags");
	}
	ret = this.serviceTags;
	}
	} catch (InterruptedException exception) {
	LOG.error("getLatestOrCached:lock got interrupted..", exception);
	} finally {
	if (lockResult) {
	lock.unlock();
	}
	}
	if (LOG.isDebugEnabled()) {
	LOG.debug("<== RangerServiceTagsCache.getLatestOrCached(lastKnownVersion=" + lastKnownVersion + ", " + needsBackwardCompatibility + "): " + ret);
	}

	return ret;
	}

	boolean getLatest(String serviceName, TagStore tagStore) throws Exception {
	if (LOG.isDebugEnabled()) {
	LOG.debug("==> ServiceTagsWrapper.getLatest(" + serviceName + ")");
	}

	boolean isCacheCompletelyLoaded = false;

	final Long cachedServiceTagsVersion = serviceTags != null ? serviceTags.getTagVersion() : -1L;

	if (LOG.isDebugEnabled()) {
	LOG.debug("Found ServiceTags in-cache : " + (serviceTags != null));
	}

	Long tagVersionInDb = tagStore.getTagVersion(serviceName);

	if (serviceTags == null \|\| tagVersionInDb == null \|\| !tagVersionInDb.equals(cachedServiceTagsVersion)) {
	if (LOG.isDebugEnabled()) {
	LOG.debug("loading serviceTags from db ... cachedServiceTagsVersion=" + cachedServiceTagsVersion + ", tagVersionInDb=" + tagVersionInDb);
	}

	long startTimeMs = System.currentTimeMillis();

	ServiceTags serviceTagsFromDb = tagStore.getServiceTags(serviceName, cachedServiceTagsVersion);

	long dbLoadTime = System.currentTimeMillis() - startTimeMs;

	if (dbLoadTime > longestDbLoadTimeInMs) {
	longestDbLoadTimeInMs = dbLoadTime;
	}
	updateTime = new Date();

	if (serviceTagsFromDb != null) {
	if (serviceTags == null) {
	if (LOG.isDebugEnabled()) {
	LOG.debug("Initializing ServiceTags cache for the first time");
	}
	serviceTags = serviceTagsFromDb;
	this.deltaCache = null;
	pruneUnusedAttributes();
	isCacheCompletelyLoaded = true;
	} else if (!serviceTagsFromDb.getIsDelta()) {
	// service-tags are loaded because of some disqualifying event
	if (LOG.isDebugEnabled()) {
	LOG.debug("Complete set of tag are loaded from database, because of some disqualifying event or because tag-delta is not supported");
	}
	serviceTags = serviceTagsFromDb;
	this.deltaCache = null;
	pruneUnusedAttributes();
	isCacheCompletelyLoaded = true;
	} else { // Previously cached service tags are still valid - no disqualifying change
	// Rebuild tags cache from original tags and deltas
	if (LOG.isDebugEnabled()) {
	LOG.debug("Retrieved tag-deltas from database. These will be applied on top of ServiceTags version:[" + cachedServiceTagsVersion + "], tag-deltas:[" + serviceTagsFromDb.getTagVersion() + "]");
	}
	RangerServiceTagsDeltaUtil.applyDelta(serviceTags, serviceTagsFromDb);
	this.deltaCache = new ServiceTagsDeltasCache(cachedServiceTagsVersion, serviceTagsFromDb);
	}
	} else {
	LOG.error("Could not get tags from database, from-version:[" + cachedServiceTagsVersion + ")");
	}
	if (LOG.isDebugEnabled()) {
	LOG.debug("ServiceTags old-version:[" + cachedServiceTagsVersion + "], new-version:[" + serviceTags.getTagVersion() + "]");
	}
	} else {
	if (LOG.isDebugEnabled()) {
	LOG.debug("ServiceTags Cache already has the latest version, version:[" + cachedServiceTagsVersion + "]");
	}
	}

	if (LOG.isDebugEnabled()) {
	LOG.debug("<== ServiceTagsWrapper.getLatest(" + serviceName + "): " + isCacheCompletelyLoaded);
	}

	return isCacheCompletelyLoaded;
	}

	private void pruneUnusedAttributes() {
	RangerServiceTagsDeltaUtil.pruneUnusedAttributes(this.serviceTags);
	}

	StringBuilder toString(StringBuilder sb) {
	sb.append("RangerServiceTagsWrapper={");

	sb.append("updateTime=").append(updateTime)
	.append(", longestDbLoadTimeInMs=").append(longestDbLoadTimeInMs)
	.append(", Service-Version:").append(serviceTags != null ? serviceTags.getTagVersion() : "null")
	.append(", Number-Of-Tags:").append(serviceTags != null ? serviceTags.getTags().size() : 0);

	sb.append("} ");

	return sb;
	}

	@Override
	public String toString() {
	StringBuilder sb = new StringBuilder();

	toString(sb);

	return sb.toString();
	}
	}
	}