TableStats.java

/*
** Module   : TableStats.java
** Abstract : Table CRUD operations statistics holder
**
** Copyright (c) 2013-2022, Golden Code Development Corporation.
**
** -#- -I- --Date-- --------------------------------------Description----------------------------------------
** 001 IAS 20200819 Created initial version.
** 002 ECF 20220630 Code cleanup.
*/

/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
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** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
**     You may not represent yourself for publicity purposes as associated with
**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
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**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.persist.meta;

import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;

/**
 * Table CRUD operations statistics holder
 */
public class TableStats
{
   /** Statistics guard */
   private final ReentrantReadWriteLock guard = new ReentrantReadWriteLock();
   
   /** Database CRUD operations statistics version */
   private final AtomicLong statisticsVersion;
   
   /** Number of creates */
   private final AtomicLong create = new AtomicLong(0);
   
   /** Number of retrieves */
   private final AtomicLong retrieve = new AtomicLong(0);
   
   /** Number of updates */
   private final AtomicLong update = new AtomicLong(0);
   
   /** Number of deletes */
   private final AtomicLong delete = new AtomicLong(0);
   
   /** Table statistics version */
   private final AtomicLong version = new AtomicLong(0);
   
   /** Table statistics version last persisted */
   private final AtomicLong persisted = new AtomicLong(-1);
   
   /**
    * Constructor.
    * 
    * @param   statisticsVersion
    *          database CRUD operations statistics
    */
   public TableStats(AtomicLong statisticsVersion)
   {
      super();
      this.statisticsVersion = statisticsVersion;
   }
   
   /**
    * Register create
    */
   public void create()
   {
      guard.readLock().lock();
      try
      {
         create.incrementAndGet();
         version.incrementAndGet();
      }
      finally
      {
         guard.readLock().unlock();
      }
      statisticsVersion.incrementAndGet();
   }
   
   /**
    * Register retrieve
    */
   public void retrieve()
   {
      guard.readLock().lock();
      try
      {
         retrieve.incrementAndGet();
         version.incrementAndGet();
      }
      finally
      {
         guard.readLock().unlock();
      }
      statisticsVersion.incrementAndGet();
   }
   
   /**
    * Register update
    */
   public void update()
   {
      guard.readLock().lock();
      try
      {
         update.incrementAndGet();
         version.incrementAndGet();
      }
      finally
      {
         guard.readLock().unlock();
      }
      statisticsVersion.incrementAndGet();
   }
   
   /**
    * Register delete
    */
   public void delete()
   {
      guard.readLock().lock();
      try
      {
         delete.incrementAndGet();
         version.incrementAndGet();
      }
      finally
      {
         guard.readLock().unlock();
      }
      statisticsVersion.incrementAndGet();
   }
   
   /**
    * Get table statistics version
    * 
    * @return  table statistics version
    */
   public long version()
   {
      return version.get();
   }
   
   /**
    * Get table statistics version last persisted
    * 
    * @return  table statistics version last persisted
    */
   public long persisted()
   {
      return persisted.get();
   }
   
   /**
    * Set table statistics version last persisted
    * 
    * @param   version
    *          table statistics version last persisted
    */
   public void persisted(long version)
   {
      persisted.set(version);
   }
   
   /**
    * Get table statistics snapshot
    * 
    * @return  long[5] array. First four entries contain CRUD operation counters, the last one holds 
    *          table statistics version.  
    */
   public Snapshot getStat()
   {
      guard.writeLock().lock();
      try
      {
         return new Snapshot(create.get(),
                             retrieve.get(),
                             update.get(),
                             delete.get(),
                             version.get(),
                             persisted.get());
      }
      finally
      {
         guard.writeLock().unlock();
      }
   }
   
   /**
    * Table statistics snapshot
    */
   public static class Snapshot
   {
      /** Number of creates */
      public final long create;
      
      /** Number of retrieves */
      public final long retrieve;
      
      /** Number of updates */
      public final long update;
      
      /** Number of deletes */
      public final long delete;
      
      /** Table statistics version */
      public final long version;
      
      /** Table statistics version last persisted */
      public final long persisted;
      
      /**
       * Constructor
       * @param   create
       *          Number of creates
       * @param   retrieve
       *          Number of retrieves
       * @param   update
       *          Number of updates
       * @param   delete
       *          Number of deletes
       * @param   version
       *          Table statistics version
       * @param   persisted
       *          Table statistics version last persisted
       */
      public Snapshot(long create, long retrieve, long update, long delete, long version, long persisted)
      {
         super();
         this.create = create;
         this.retrieve = retrieve;
         this.update = update;
         this.delete = delete;
         this.version = version;
         this.persisted = persisted;
      }
   }
}