/*
    *   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.
   *
   */
  package org.apache.directory.server.xdbm;
  
  
  import java.util.Comparator;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.apache.directory.api.ldap.model.exception.LdapException;
  import org.apache.directory.api.ldap.model.schema.SchemaManager;
  import org.apache.directory.server.core.api.partition.PartitionTxn;
  import org.apache.directory.server.i18n.I18n;
  
  
  /**
   * A Abstract Table implementation aggregating the methods common with all the 
   * different Table implementation.
   *
   * @param <K> The key
   * @param <V> The stored value
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public abstract class AbstractTable<K, V> implements Table<K, V>
  {
      /** the name of this table */
      protected final String name;
  
      /** The global SchemaManager */
      protected SchemaManager schemaManager;
  
      /** a key comparator for the keys in this Table */
      protected final Comparator<K> keyComparator;
  
      /** a value comparator for the values in this Table */
      protected final Comparator<V> valueComparator;
  
      /** the current count of Tuples in this Table */
      protected long count;
  
      /** whether or not this table allows for duplicates */
      protected boolean allowsDuplicates;
  
      /** A counter used to differ the commit on disk after N operations */
      protected AtomicInteger commitNumber;
  
  
      /**
       * Create an instance of Table
       * 
       * @param schemaManager The server schemaManager
       * @param name the name of the table
       * @param keyComparator a key comparator
       * @param valueComparator a value comparator
       */
      protected AbstractTable( SchemaManager schemaManager, String name, Comparator<K> keyComparator,
          Comparator<V> valueComparator )
      {
          this.schemaManager = schemaManager;
          this.name = name;
  
          if ( keyComparator == null )
          {
              throw new IllegalArgumentException( I18n.err( I18n.ERR_591 ) );
          }
          else
          {
              this.keyComparator = keyComparator;
          }
  
          this.valueComparator = valueComparator;
  
          commitNumber = new AtomicInteger( 0 );
      }
  
  
      /**
       * {@inheritDoc}
       */
      public Comparator<K> getKeyComparator()
      {
          return keyComparator;
      }
 
 
     /**
      * {@inheritDoc}
      */
     public Comparator<V> getValueComparator()
     {
         return valueComparator;
     }
 
 
     /**
      * {@inheritDoc}
      */
     public String getName()
     {
         return name;
     }
 
 
     /**
      * {@inheritDoc}
      */
     public long count( PartitionTxn transaction ) throws LdapException
     {
         return count;
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public long greaterThanCount( PartitionTxn transaction, K key ) throws LdapException
     {
         // take a best guess
         return Math.min( count, 10L );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public long lessThanCount( PartitionTxn transaction, K key ) throws LdapException
     {
         // take a best guess
         return Math.min( count, 10L );
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean isDupsEnabled()
     {
         return allowsDuplicates;
     }
 
 
     /**
      * @see Object#toString()
      */
     public String toString()
     {
         StringBuilder sb = new StringBuilder();
 
         sb.append( "Name    : " ).append( name ).append( '\n' );
         sb.append( "NbElems : " ).append( count ).append( '\n' );
         sb.append( "Dups    : " ).append( allowsDuplicates ).append( '\n' );
         sb.append( "Key     : " ).append( keyComparator.getClass().getName() ).append( '\n' );
         sb.append( "Value   : " ).append( valueComparator.getClass().getName() ).append( '\n' );
 
         return sb.toString();
     }
 }