public  void configure(Type type,
    Properties params,
    Dialect dialect) throws MappingException 
{
		tableName = PropertiesHelper.getString(ID_TABLE, params, DEFAULT_TABLE);
		pkColumnName = PropertiesHelper.getString(PK_COLUMN_NAME, params, DEFAULT_PK_COLUMN);
		valueColumnName = PropertiesHelper.getString(VALUE_COLUMN_NAME, params, DEFAULT_VALUE_COLUMN);
		String schemaName = params.getProperty(SCHEMA);
		String catalogName = params.getProperty(CATALOG);
		keySize = PropertiesHelper.getInt(PK_LENGTH_NAME, params, DEFAULT_PK_LENGTH);
		String keyValue = PropertiesHelper.getString(PK_VALUE_NAME, params, params.getProperty(TABLE) );
		if ( tableName.indexOf( '.' )< 0 ) {
			tableName = Table.qualify( catalogName, schemaName, tableName );
		}
		query = "select " +
			valueColumnName +
			" from " +
			dialect.appendLockHint(LockMode.UPGRADE, tableName) +
			" where " + pkColumnName + " = '" + keyValue + "'" +
			dialect.getForUpdateString();
		update = "update " +
			tableName +
			" set " +
			valueColumnName +
			" = ? where " +
			valueColumnName +
			" = ? and " +
			pkColumnName +
			" = '" + 
			keyValue 
			+ "'";
		insert = "insert into " + tableName +
			"(" + pkColumnName + ", " +	valueColumnName + ") " +
			"values('"+ keyValue +"', ?)";
		//hilo config
		maxLo = PropertiesHelper.getInt(MAX_LO, params, Short.MAX_VALUE);
		lo = maxLo + 1; // so we "clock over" on the first invocation
		returnClass = type.getReturnedClass();
}

 public Serializable doWorkInCurrentTransaction(Connection conn,
    String sql) throws SQLException 
{
		int result;
		int rows;
		do {
			// The loop ensures atomicity of the
			// select + update even for no transaction
			// or read committed isolation level
			//sql = query;
			SQL_STATEMENT_LOGGER.logStatement( sql, FormatStyle.BASIC );
			PreparedStatement qps = conn.prepareStatement(query);
			PreparedStatement ips = null;
			try {
				//qps.setString(1, key);
				ResultSet rs = qps.executeQuery();
				boolean isInitialized = rs.next();
				if ( !isInitialized ) {
					result = 0;
					ips = conn.prepareStatement(insert);
					//ips.setString(1, key);
					ips.setInt(1, result);
					ips.execute();
				}
				else {
					result = rs.getInt(1);
				}
				rs.close();
			}
			catch (SQLException sqle) {
				log.error("could not read or init a hi value", sqle);
				throw sqle;
			}
			finally {
				if (ips != null) {
					ips.close();
				}
				qps.close();
			}
			//sql = update;
			PreparedStatement ups = conn.prepareStatement(update);
			try {
				ups.setInt( 1, result + 1 );
				ups.setInt( 2, result );
				//ups.setString( 3, key );
				rows = ups.executeUpdate();
			}
			catch (SQLException sqle) {
				log.error("could not update hi value in: " + tableName, sqle);
				throw sqle;
			}
			finally {
				ups.close();
			}
		}
		while (rows==0);
		return new Integer(result);
}

 public synchronized Serializable generate(SessionImplementor session,
    Object obj) throws HibernateException 
{
		if (maxLo <  1) {
			//keep the behavior consistent even for boundary usages
			int val = ( (Integer) doWorkInNewTransaction(session) ).intValue();
			if (val == 0) val = ( (Integer) doWorkInNewTransaction(session) ).intValue();
			return IdentifierGeneratorFactory.createNumber( val, returnClass );
		}
		if (lo >maxLo) {
			int hival = ( (Integer) doWorkInNewTransaction(session) ).intValue();
			lo = (hival == 0) ? 1 : 0;
			hi = hival * (maxLo+1);
			log.debug("new hi value: " + hival);
		}
		return IdentifierGeneratorFactory.createNumber( hi + lo++, returnClass );
}

 public Object generatorKey() 
{
		return tableName;
}

 public String[] sqlCreateStrings(Dialect dialect) throws HibernateException 
{
		return new String[] {
			new StringBuffer( dialect.getCreateTableString() )
					.append( ' ' )
					.append( tableName )
					.append( " ( " )
					.append( pkColumnName )
					.append( ' ' )
					.append( dialect.getTypeName( Types.VARCHAR, keySize, 0, 0 ) )
					.append( ",  " )
					.append( valueColumnName )
					.append( ' ' )
					.append( dialect.getTypeName( Types.INTEGER ) )
					.append( " ) " )
					.toString()
		};
}

 public String[] sqlDropStrings(Dialect dialect) throws HibernateException 
{
		StringBuffer sqlDropString = new StringBuffer( "drop table " );
		if ( dialect.supportsIfExistsBeforeTableName() ) {
			sqlDropString.append( "if exists " );
		}
		sqlDropString.append( tableName ).append( dialect.getCascadeConstraintsString() );
		if ( dialect.supportsIfExistsAfterTableName() ) {
			sqlDropString.append( " if exists" );
		}
		return new String[] { sqlDropString.toString() };
}