/**
    *    Copyright 2010-2016 the original author or authors.
    *
    *    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.mybatis.caches.oscache;
  
  import java.util.concurrent.locks.ReadWriteLock;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  import org.apache.ibatis.cache.Cache;
  
  import com.opensymphony.oscache.base.NeedsRefreshException;
  import com.opensymphony.oscache.general.GeneralCacheAdministrator;
  
  /**
   * The OSCache-based Cache implementation.
   */
  public final class OSCache implements Cache {
  
      /**
       * The shared 
       */
      private static final GeneralCacheAdministrator CACHE_ADMINISTRATOR = new GeneralCacheAdministrator();
  
      /**
       * The {@code ReadWriteLock}.
       */
      private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
  
      /**
       * This cache id.
       */
      private final String id;
  
      /**
       * Builds a new OSCache-based Cache.
       *
       * @param id the Mapper id.
       */
      public OSCache(final String id) {
          if (id == null) {
              throw new IllegalArgumentException("Cache instances require an ID");
          }
          this.id = id;
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void clear() {
          CACHE_ADMINISTRATOR.flushGroup(this.id);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String getId() {
          return this.id;
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public Object getObject(Object key) {
          String keyString = key.toString();
          Object ret = null;
  
          try {
              ret = CACHE_ADMINISTRATOR.getFromCache(keyString);
          } catch (NeedsRefreshException e) {
              CACHE_ADMINISTRATOR.cancelUpdate(keyString);
          }
  
          return ret;
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public ReadWriteLock getReadWriteLock() {
          return this.readWriteLock;
      }
  
      /**
      * {@inheritDoc}
      */
     @Override
     public int getSize() {
         return CACHE_ADMINISTRATOR.getCache().getSize();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void putObject(Object key, Object value) {
         CACHE_ADMINISTRATOR.putInCache(key.toString(), value, new String[] { this.id });
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Object removeObject(Object key) {
         String keyString = key.toString();
         Object ret = null;
 
         try {
             ret = CACHE_ADMINISTRATOR.getFromCache(keyString);
         } catch (NeedsRefreshException e) {
             CACHE_ADMINISTRATOR.cancelUpdate(keyString);
         }
 
         if (ret != null) {
             CACHE_ADMINISTRATOR.flushEntry(keyString);
         }
 
         return ret;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean equals(Object obj) {
         if (this == obj) {
             return true;
         }
         if (obj == null) {
             return false;
         }
         if (!(obj instanceof Cache)) {
             return false;
         }
 
         Cache otherCache = (Cache) obj;
         return this.id.equals(otherCache.getId());
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public int hashCode() {
         return this.id.hashCode();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public String toString() {
         return "OSCache {"
                 + this.id
                 + "}";
     }
 
 }