package org.apache.commons.jcs3.auxiliary.lateral;
   
   /*
    * 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.
   */
  
  import java.io.IOException;
  import java.rmi.UnmarshalException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import org.apache.commons.jcs3.auxiliary.AbstractAuxiliaryCache;
  import org.apache.commons.jcs3.auxiliary.lateral.behavior.ILateralCacheAttributes;
  import org.apache.commons.jcs3.engine.CacheAdaptor;
  import org.apache.commons.jcs3.engine.CacheEventQueueFactory;
  import org.apache.commons.jcs3.engine.CacheInfo;
  import org.apache.commons.jcs3.engine.CacheStatus;
  import org.apache.commons.jcs3.engine.behavior.ICacheElement;
  import org.apache.commons.jcs3.engine.behavior.ICacheEventQueue;
  import org.apache.commons.jcs3.engine.behavior.ICacheServiceNonLocal;
  import org.apache.commons.jcs3.engine.stats.StatElement;
  import org.apache.commons.jcs3.engine.stats.Stats;
  import org.apache.commons.jcs3.engine.stats.behavior.IStatElement;
  import org.apache.commons.jcs3.engine.stats.behavior.IStats;
  import org.apache.commons.jcs3.log.Log;
  import org.apache.commons.jcs3.log.LogManager;
  
  /**
   * Used to queue up update requests to the underlying cache. These requests will be processed in
   * their order of arrival via the cache event queue processor.
   */
  public class LateralCacheNoWait<K, V>
      extends AbstractAuxiliaryCache<K, V>
  {
      /** The logger. */
      private static final Log log = LogManager.getLog( LateralCacheNoWait.class );
  
      /** The cache */
      private final LateralCache<K, V> cache;
  
      /** Identify this object */
      private String identityKey;
  
      /** The event queue */
      private ICacheEventQueue<K, V> eventQueue;
  
      /** times get called */
      private int getCount;
  
      /** times remove called */
      private int removeCount;
  
      /** times put called */
      private int putCount;
  
      /**
       * Constructs with the given lateral cache, and fires up an event queue for asynchronous
       * processing.
       * <p>
       * @param cache
       */
      public LateralCacheNoWait( final LateralCache<K, V> cache )
      {
          this.cache = cache;
          this.identityKey = cache.getCacheName();
          this.setCacheEventLogger(cache.getCacheEventLogger());
          this.setElementSerializer(cache.getElementSerializer());
  
          log.debug( "Constructing LateralCacheNoWait, LateralCache = [{0}]", cache );
  
          final CacheEventQueueFactory<K, V> fact = new CacheEventQueueFactory<>();
          this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor<>( cache ),
                  CacheInfo.listenerId, cache.getCacheName(),
                  getAuxiliaryCacheAttributes().getEventQueuePoolName(),
                  getAuxiliaryCacheAttributes().getEventQueueType() );
  
          // need each no wait to handle each of its real updates and removes,
          // since there may
          // be more than one per cache? alternative is to have the cache
         // perform updates using a different method that specifies the listener
         // this.q = new CacheEventQueue(new CacheAdaptor(this),
         // LateralCacheInfo.listenerId, cache.getCacheName());
         if ( cache.getStatus() == CacheStatus.ERROR )
         {
             eventQueue.destroy();
         }
     }
 
     /**
      * The identifying key to this no wait
      *
      * @return the identity key
      * @since 3.1
      */
     public String getIdentityKey()
     {
         return identityKey;
     }
 
     /**
      * Set the identifying key to this no wait
      *
      * @param identityKey the identityKey to set
      * @since 3.1
      */
     public void setIdentityKey(String identityKey)
     {
         this.identityKey = identityKey;
     }
 
     /**
      * @param ce
      * @throws IOException
      */
     @Override
     public void update( final ICacheElement<K, V> ce )
         throws IOException
     {
         putCount++;
         try
         {
             eventQueue.addPutEvent( ce );
         }
         catch ( final IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }
 
     /**
      * Synchronously reads from the lateral cache.
      * <p>
      * @param key
      * @return ICacheElement&lt;K, V&gt; if found, else null
      */
     @Override
     public ICacheElement<K, V> get( final K key )
     {
         getCount++;
         if ( this.getStatus() != CacheStatus.ERROR )
         {
             try
             {
                 return cache.get( key );
             }
             catch ( final UnmarshalException ue )
             {
                 log.debug( "Retrying the get owing to UnmarshalException..." );
                 try
                 {
                     return cache.get( key );
                 }
                 catch ( final IOException ex )
                 {
                     log.error( "Failed in retrying the get for the second time." );
                     eventQueue.destroy();
                 }
             }
             catch ( final IOException ex )
             {
                 eventQueue.destroy();
             }
         }
         return null;
     }
 
     /**
      * Gets multiple items from the cache based on the given set of keys.
      * <p>
      * @param keys
      * @return a map of K key to ICacheElement&lt;K, V&gt; element, or an empty map if there is no
      *         data in cache for any of these keys
      */
     @Override
     public Map<K, ICacheElement<K, V>> getMultiple(final Set<K> keys)
     {
         if ( keys != null && !keys.isEmpty() )
         {
             return keys.stream()
                 .collect(Collectors.toMap(
                         key -> key,
                         this::get)).entrySet().stream()
                     .filter(entry -> entry.getValue() != null)
                     .collect(Collectors.toMap(
                             Entry::getKey,
                             Entry::getValue));
         }
 
         return new HashMap<>();
     }
 
     /**
      * Synchronously reads from the lateral cache.
      * <p>
      * @param pattern
      * @return ICacheElement&lt;K, V&gt; if found, else empty
      */
     @Override
     public Map<K, ICacheElement<K, V>> getMatching(final String pattern)
     {
         getCount++;
         if ( this.getStatus() != CacheStatus.ERROR )
         {
             try
             {
                 return cache.getMatching( pattern );
             }
             catch ( final UnmarshalException ue )
             {
                 log.debug( "Retrying the get owing to UnmarshalException." );
                 try
                 {
                     return cache.getMatching( pattern );
                 }
                 catch ( final IOException ex )
                 {
                     log.error( "Failed in retrying the get for the second time." );
                     eventQueue.destroy();
                 }
             }
             catch ( final IOException ex )
             {
                 eventQueue.destroy();
             }
         }
         return Collections.emptyMap();
     }
 
     /**
      * Return the keys in this cache.
      * <p>
      * @see org.apache.commons.jcs3.auxiliary.AuxiliaryCache#getKeySet()
      */
     @Override
     public Set<K> getKeySet() throws IOException
     {
         try
         {
             return cache.getKeySet();
         }
         catch ( final IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
         return Collections.emptySet();
     }
 
     /**
      * Adds a remove request to the lateral cache.
      * <p>
      * @param key
      * @return always false
      */
     @Override
     public boolean remove( final K key )
     {
         removeCount++;
         try
         {
             eventQueue.addRemoveEvent( key );
         }
         catch ( final IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
         return false;
     }
 
     /** Adds a removeAll request to the lateral cache. */
     @Override
     public void removeAll()
     {
         try
         {
             eventQueue.addRemoveAllEvent();
         }
         catch ( final IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }
 
     /** Adds a dispose request to the lateral cache. */
     @Override
     public void dispose()
     {
         try
         {
             eventQueue.addDisposeEvent();
         }
         catch ( final IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }
 
     /**
      * No lateral invocation.
      * <p>
      * @return The size value
      */
     @Override
     public int getSize()
     {
         return cache.getSize();
     }
 
     /**
      * No lateral invocation.
      * <p>
      * @return The cacheType value
      */
     @Override
     public CacheType getCacheType()
     {
         return cache.getCacheType();
     }
 
     /**
      * Returns the async cache status. An error status indicates either the lateral connection is not
      * available, or the asyn queue has been unexpectedly destroyed. No lateral invocation.
      * <p>
      * @return The status value
      */
     @Override
     public CacheStatus getStatus()
     {
         return eventQueue.isWorking() ? cache.getStatus() : CacheStatus.ERROR;
     }
 
     /**
      * Gets the cacheName attribute of the LateralCacheNoWait object
      * <p>
      * @return The cacheName value
      */
     @Override
     public String getCacheName()
     {
         return cache.getCacheName();
     }
 
     /**
      * Replaces the lateral cache service handle with the given handle and reset the queue by
      * starting up a new instance.
      * <p>
      * @param lateral
      */
     public void fixCache( final ICacheServiceNonLocal<K, V> lateral )
     {
         cache.fixCache( lateral );
         resetEventQ();
     }
 
     /**
      * Resets the event q by first destroying the existing one and starting up new one.
      */
     public void resetEventQ()
     {
         if ( eventQueue.isWorking() )
         {
             eventQueue.destroy();
         }
         final CacheEventQueueFactory<K, V> fact = new CacheEventQueueFactory<>();
         this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor<>( cache ),
                 CacheInfo.listenerId, cache.getCacheName(),
                 getAuxiliaryCacheAttributes().getEventQueuePoolName(),
                 getAuxiliaryCacheAttributes().getEventQueueType() );
     }
 
     /**
      * @return Returns the AuxiliaryCacheAttributes.
      */
     @Override
     public ILateralCacheAttributes getAuxiliaryCacheAttributes()
     {
         return cache.getAuxiliaryCacheAttributes();
     }
 
     /**
      * getStats
      * @return String
      */
     @Override
     public String getStats()
     {
         return getStatistics().toString();
     }
 
     /**
      * this won't be called since we don't do ICache logging here.
      * <p>
      * @return String
      */
     @Override
     public String getEventLoggingExtraInfo()
     {
         return "Lateral Cache No Wait";
     }
 
     /**
      * @return statistics about this communication
      */
     @Override
     public IStats getStatistics()
     {
         final IStats stats = new Stats();
         stats.setTypeName( "Lateral Cache No Wait" );
 
         // get the stats from the event queue too
         final IStats eqStats = this.eventQueue.getStatistics();
         final ArrayList<IStatElement<?>> elems = new ArrayList<>(eqStats.getStatElements());
 
         elems.add(new StatElement<>( "Get Count", Integer.valueOf(this.getCount) ) );
         elems.add(new StatElement<>( "Remove Count", Integer.valueOf(this.removeCount) ) );
         elems.add(new StatElement<>( "Put Count", Integer.valueOf(this.putCount) ) );
         elems.add(new StatElement<>( "Attributes", cache.getAuxiliaryCacheAttributes() ) );
 
         stats.setStatElements( elems );
 
         return stats;
     }
 
     /**
      * @return debugging info.
      */
     @Override
     public String toString()
     {
         final StringBuilder buf = new StringBuilder();
         buf.append( " LateralCacheNoWait " );
         buf.append( " Status = " + this.getStatus() );
         buf.append( " cache = [" + cache.toString() + "]" );
         return buf.toString();
     }
 }