package com.atlassian.cache.hazelcast;
   
   import com.atlassian.cache.CacheSettings;
   
   import com.hazelcast.config.MapConfig;
   import com.hazelcast.config.MaxSizeConfig;
   
   import static com.hazelcast.config.MaxSizeConfig.MaxSizePolicy.PER_NODE;
   
  /**
   * Performs the (re)configuration of Hazelcast {@link MapConfig} objects.
   *
   * @since 2.4.0
   */
  public class HazelcastMapConfigConfigurator
  {
      // If the cache is a hybrid cache, only the entry versions are tracked in the IMap. These versions should remain
      // cached longer than the values in local caches. A multiplier is applied to the config parameters that affect
      // cache eviction to enforce this.
      public static final int HYBRID_MULTIPLIER = 2;
  
      public MapConfig configureMapConfig(CacheSettings settings, MapConfig mapConfig)
      {
          boolean hybrid = !settings.getReplicateViaCopy(true);
          Integer multiplier = hybrid ? HYBRID_MULTIPLIER : 1;
          Integer maxEntries = settings.getMaxEntries();
          if (maxEntries != null)
          {
              mapConfig.setMaxSizeConfig(new MaxSizeConfig().setMaxSizePolicy(PER_NODE).setSize(multiplier * maxEntries));
              mapConfig.setEvictionPolicy(MapConfig.EvictionPolicy.LFU);
          }
  
          final Long expireAfterAccess = settings.getExpireAfterAccess();
          if (expireAfterAccess != null)
          {
              mapConfig.setMaxIdleSeconds(multiplier * roundUpToWholeSeconds(expireAfterAccess));
          }
  
          final Long expireAfterWrite = settings.getExpireAfterWrite();
          if (expireAfterWrite != null)
          {
              mapConfig.setTimeToLiveSeconds(multiplier * roundUpToWholeSeconds(expireAfterWrite));
          }
  
          return mapConfig;
      }
  
      private static int roundUpToWholeSeconds(final Long expireAfterAccess)
      {
          return (int) Math.ceil(expireAfterAccess / 1000d);
      }
  }