content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * Licensed 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.activiti.engine.impl.persistence.deploy;
  
  import static java.util.Collections.synchronizedMap;
  
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Default cache: keep everything in memory, unless a limit is set.
   *
  
   */
  public class DefaultDeploymentCache<T> implements DeploymentCache<T> {
  
      private static final Logger logger = LoggerFactory.getLogger(DefaultDeploymentCache.class);
  
      protected Map<String, T> cache;
  
      /** Cache with no limit */
      public DefaultDeploymentCache() {
          this.cache = synchronizedMap(new HashMap<String, T>());
      }
  
      /**
       * Cache which has a hard limit: no more elements will be cached than the limit.
       */
      public DefaultDeploymentCache(final int limit) {
          this.cache = synchronizedMap(
              new LinkedHashMap<String, T>(limit + 1, 0.75f, true) {
                  // +1 is needed, because the entry is inserted first, before it is removed
                  // 0.75 is the default (see javadocs)
                  // true will keep the 'access-order', which is needed to have a real LRU cache
                  private static final long serialVersionUID = 1L;
  
                  protected boolean removeEldestEntry(Map.Entry<String, T> eldest) {
                      boolean removeEldest = size() > limit;
                      if (removeEldest && logger.isTraceEnabled()) {
                          logger.trace("Cache limit {} is reached, {} will be evicted", limit, eldest.getKey());
                      }
                      return removeEldest;
                  }
              }
          );
      }
  
      public T get(String id) {
          return cache.get(id);
      }
  
      public void add(String id, T obj) {
          cache.put(id, obj);
      }
  
      public void remove(String id) {
          cache.remove(id);
      }
  
      @Override
      public boolean contains(String id) {
          return cache.containsKey(id);
      }
  
      public void clear() {
          cache.clear();
      }
  
      // For testing purposes only
      public int size() {
          return cache.size();
      }
  }
  