content: /*
   * Solo - A small and beautiful blogging system written in Java.
   * Copyright (c) 2010-present, b3log.org
   *
   * Solo is licensed under Mulan PSL v2.
   * You can use this software according to the terms and conditions of the Mulan PSL v2.
   * You may obtain a copy of Mulan PSL v2 at:
   *         http://license.coscl.org.cn/MulanPSL2
   * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
   * See the Mulan PSL v2 for more details.
   */
  package org.b3log.solo.cache;
  
  import org.b3log.latke.Keys;
  import org.b3log.latke.ioc.Singleton;
  import org.b3log.solo.model.Article;
  import org.b3log.solo.util.Solos;
  import org.json.JSONObject;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * Article cache.
   *
   * @author <a href="http://88250.b3log.org">Liang Ding</a>
   * @version 1.2.1.0, Sep 20, 2019
   * @since 2.3.0
   */
  @Singleton
  public class ArticleCache {
  
      /**
       * Article id cache.
       */
      private final Map<String, JSONObject> idCache = new ConcurrentHashMap<>();
  
      /**
       * Article permalink cache.
       */
      private final Map<String, JSONObject> permalinkCache = new ConcurrentHashMap<>();
  
      /**
       * Gets an article by the specified article id.
       *
       * @param id the specified article id
       * @return article, returns {@code null} if not found
       */
      public JSONObject getArticle(final String id) {
          final JSONObject article = idCache.get(id);
          if (null == article) {
              return null;
          }
  
          return Solos.clone(article);
      }
  
      /**
       * Gets an article by the specified article permalink.
       *
       * @param permalink the specified article permalink
       * @return article, returns {@code null} if not found
       */
      public JSONObject getArticleByPermalink(final String permalink) {
          final JSONObject article = permalinkCache.get(permalink);
          if (null == article) {
              return null;
          }
  
          return Solos.clone(article);
      }
  
      /**
       * Adds or updates the specified article.
       *
       * @param article the specified article
       */
      public void putArticle(final JSONObject article) {
          idCache.put(article.optString(Keys.OBJECT_ID), Solos.clone(article));
          permalinkCache.put(article.optString(Article.ARTICLE_PERMALINK), Solos.clone(article));
      }
  
      /**
       * Removes an article by the specified article id.
       *
       * @param id the specified article id
       */
      public void removeArticle(final String id) {
          final JSONObject article = idCache.get(id);
          if (null == article) {
              return;
          }
          final String permalink = article.optString(Article.ARTICLE_PERMALINK);
          idCache.remove(id);
          permalinkCache.remove(permalink);
      }
  
      /**
       * Clears all cached data.
       */
      public void clear() {
          idCache.clear();
          permalinkCache.clear();
      }
  }