#region License
// Persist library : Persistence layer
// Copyright (C) 2003 Vincent Daron
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#endregion
using System;
using Persist;
namespace Persist.IdGenerators{
/// <summary>
/// Basic High/Low Unique Id Implementation (UInt64 Id).
/// Sub class must implement the method to retreive the next High Value
/// </summary>
public abstract class AbstractHighLowIdGenerator : IIdGenerator
{
private UInt64 currentLowValue = 0;
private UInt64 currentHighValue = 0;
/// <summary>
/// Return the new Id
/// </summary>
/// <param name="classMap">the classMap</param>
/// <returns>UInt64 Identifier</returns>
public object GetNewId(Persist.Maps.ClassMap classMap)
{
currentLowValue++;
if (currentHighValue == 0 || currentLowValue == ulong.MaxValue)
{
currentLowValue = 0;
currentHighValue = GetNextHighValue(classMap);
}
return (currentHighValue | currentLowValue );
}
/// <summary>
/// Return the Next UInt64 High Value for the specified ClassMap
/// </summary>
/// <param name="classMap">the ClassMap</param>
/// <returns>the Next High Value</returns>
protected abstract UInt64 GetNextHighValue(Persist.Maps.ClassMap classMap);
/// <summary>
/// Initialize IIdGenerator Instance
/// </summary>
/// <param name="properties">Parameters</param>
public virtual void Init(System.Collections.Specialized.NameValueCollection properties)
{
}
}
}
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