| /* |
| * 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.nifi.web.security.otp; |
| |
| import com.google.common.cache.AbstractCache; |
| import com.google.common.cache.Cache; |
| import com.google.common.cache.CacheBuilder; |
| import com.google.common.cache.CacheStats; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.TimeUnit; |
| import org.apache.nifi.web.security.util.CacheKey; |
| import org.checkerframework.checker.nullness.qual.Nullable; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * This class provides a specific wrapper implementation based on the Guava {@link Cache} but with |
| * reverse-index capability because of the special use case (a user [the cache value] can only have |
| * one active token [the cache key] at a time). This allows reverse lookup semantics. |
| */ |
| public class TokenCache extends AbstractCache<CacheKey, String> { |
| private static final Logger logger = LoggerFactory.getLogger(TokenCache.class); |
| |
| private final String contentsDescription; |
| private final Cache<CacheKey, String> internalCache; |
| |
| public TokenCache(String contentsDescription, final int duration, final TimeUnit units) { |
| this.contentsDescription = contentsDescription; |
| internalCache = CacheBuilder.newBuilder().expireAfterWrite(duration, units).build(); |
| } |
| |
| /** |
| * Returns the value associated with {@code key} in this cache, or {@code null} if there is no |
| * cached value for {@code key}. |
| * |
| * @param key the (wrapped) {@code token} |
| * @since 11.0 |
| * @return the retrieved value ({@code user}) |
| */ |
| @Override |
| public @Nullable String getIfPresent(Object key) { |
| return internalCache.getIfPresent(key); |
| } |
| |
| /** |
| * Puts the provided value ({@code user}) in the cache at the provided key (wrapped {@code token}). |
| * |
| * @param key the cache key |
| * @param value the value to insert |
| * @since 11.0 |
| */ |
| @Override |
| public void put(CacheKey key, String value) { |
| internalCache.put(key, value); |
| } |
| |
| /** |
| * Returns {@code true} if the cache contains the provided value. |
| * |
| * @param value the value ({@code user}) to look for |
| * @return true if the user exists in the cache |
| */ |
| public boolean containsValue(String value) { |
| return internalCache.asMap().containsValue(value); |
| } |
| |
| /** |
| * Returns the {@link CacheKey} representing the key ({@code token}) associated with the provided value ({@code user}). |
| * |
| * @param value the value ({@code user}) to look for |
| * @return the CacheKey ({@code token}) associated with this user, or {@code null} if the user has no tokens in this cache |
| */ |
| @Nullable |
| public CacheKey getKeyForValue(String value) { |
| if (containsValue(value)) { |
| Map<CacheKey, String> cacheMap = internalCache.asMap(); |
| for (Map.Entry<CacheKey, String> e : cacheMap.entrySet()) { |
| if (e.getValue().equals(value)) { |
| return e.getKey(); |
| } |
| } |
| throw new IllegalStateException("The value existed in the cache but expired during retrieval"); |
| } else { |
| return null; |
| } |
| } |
| |
| // Override the unsupported abstract methods from the parent |
| |
| @Override |
| public void invalidate(Object key) { |
| internalCache.invalidate(key); |
| } |
| |
| @Override |
| public void invalidateAll() { |
| internalCache.invalidateAll(internalCache.asMap().keySet()); |
| } |
| |
| @Override |
| public long size() { |
| return internalCache.size(); |
| } |
| |
| @Override |
| public CacheStats stats() { |
| return internalCache.stats(); |
| } |
| |
| @Override |
| public ConcurrentMap<CacheKey, String> asMap() { |
| return internalCache.asMap(); |
| } |
| |
| /** |
| * Returns a string representation of the cache. |
| * |
| * @return a string representation of the cache |
| */ |
| @Override |
| public String toString() { |
| return new StringBuilder("TokenCache for ") |
| .append(contentsDescription) |
| .append(" with ") |
| .append(internalCache.size()) |
| .append(" elements") |
| .toString(); |
| } |
| } |