/*
    * (C) Copyright 1989-2012 Trend Micro, Inc.
    * All Rights Reserved.
    *
    * This program is an unpublished copyrighted work which is proprietary
    * to Trend Micro, Inc. and contains confidential information that is not
    * to be reproduced or disclosed to any other person or entity without
    * prior written consent from Trend Micro, Inc. in each and every instance.
    *
   * WARNING:  Unauthorized reproduction of this program as well as
   * unauthorized preparation of derivative works based upon the
   * program or distribution of copies by sale, rental, lease or
   * lending are violations of federal copyright laws and state trade
   * secret laws, punishable by civil and criminal penalties.
   */
  
  package com.trendmicro.grid.acl.ds.cache;
  
  import net.sf.tinyjee.cache.CacheContext;
  import org.infinispan.manager.EmbeddedCacheManager;
  import org.springframework.jmx.export.annotation.ManagedAttribute;
  import org.springframework.jmx.export.annotation.ManagedResource;
  import org.springframework.stereotype.Component;
  
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * Is a shared
   *
   * @author Juergen_Kellerer, 2012-07-16
   */
  @Component
  @ManagedResource(objectName = ThirdLevelCacheStatisticsSummary.OBJECT_NAME, description = "" +
  		"Implements a summary on the 3rd level cache (memcached) efficiency.")
  public class ThirdLevelCacheStatisticsSummary {
  
  	static final String JMX_NAME = "ThirdLevelCacheStatisticsSummary";
  	static final String JMX_DOMAIN = "com.trendmicro.grid.acl:";
  	static final String OBJECT_NAME = JMX_DOMAIN + "type=" + JMX_NAME + ",name=Context";
  
  	protected final AtomicLong fetchedKeyCount = new AtomicLong();
  
  	/**
  	 * Returns the number of times that the 3rd level cache was bypassed.
  	 *
  	 * @return the number of times that the 3rd level cache was bypassed.
  	 */
  	public AtomicLong getFetchedKeyCount() {
  		return fetchedKeyCount;
  	}
  
  	/**
  	 * Returns the number of times that the 3rd level cache was bypassed.
  	 * <p/>
  	 * Bypassed means that the the request hits 2nd, 1st level cache in hibernate and finally the database.
  	 *
  	 * @return the number of times that the 3rd level cache was bypassed.
  	 */
  	@ManagedAttribute(description = "The number of times that the 3rd level cache was bypassed.")
  	public long getCacheMisses() {
  		return fetchedKeyCount.get();
  	}
  
  	/**
  	 * The number of times that the 3rd level cache provided a normal result.
  	 *
  	 * @return The number of times that the 3rd level cache provided a normal result.
  	 */
  	@ManagedAttribute(description = "The number of times that the 3rd level cache provided a normal result.")
  	public long getCacheHits() {
  		return collectHits("3rdLevel.Cache");
  	}
  
  	/**
  	 * The number of times that the 3rd level cache provided a result a cached 'null' result.
  	 *
  	 * @return The number of times that the 3rd level cache provided a result a cached 'null' result.
  	 */
  	@ManagedAttribute(description = "The number of times that the 3rd level cache provided a result a cached 'null' result.")
  	public long getNegativeCacheHits() {
  		return collectHits("Internal.3rdLevel.Cache.Unknown");
  	}
  
  	private static long collectHits(String prefix) {
  		long hits = 0;
  		final CacheContext context = CacheContext.getInstance();
  		for (EmbeddedCacheManager cacheManager : context.getCacheManagers().values()) {
  			for (String name : cacheManager.getCacheNames()) {
  				if (name.startsWith(prefix))
  					hits += cacheManager.getCache(name).getAdvancedCache().getStats().getHits();
  			}
  		}
  		return hits;
  	}
  }