iplooktable.cs

精通网络应用系统开发 光盘 该书是人民邮电出版社出版的

using System;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Configuration;
using System.Net;

namespace webvisitStatistic.Reporter.IPLook
{
	/// <summary>
	/// IpLookTable 的摘要说明。
	/// </summary>
	public class IpLookTable 
	{

		public struct IpRange
		{
			public	Int64 sip;
			public  Int64 eip;
		}

		public class IpPosition
		{
			public  IpRange RangeOfIp;
			public  String  WidePos;
			public  String  NarrowPos;
			public IpPosition(Int64 startip,Int64 endip,String wPos,String nPos)
			{
				RangeOfIp.sip = startip;
				RangeOfIp.eip = endip;
				WidePos = wPos;
				NarrowPos = nPos;
			}
		}

		protected IpLookTable()
		{
			//
			// TODO: 在此处添加构造函数逻辑
			//
		}

		public void Init(String connstr)
		{
			_connString = connstr;
			using (SqlConnection conn= new SqlConnection(_connString))
			{
				SqlCommand cmd = conn.CreateCommand();
				cmd.CommandType = System.Data.CommandType.Text;
				cmd.CommandText = SelCounts;
				try
				{
					conn.Open();
					_lenOfiptable = (int)cmd.ExecuteScalar();
					// 读入数据
					_ipItems = new IpRange[_lenOfiptable];
					cmd.CommandText = SelIpPosList;
					SqlDataReader reader = cmd.ExecuteReader();
					int i = 0;
				
					while (reader.Read()) 
					{
						_ipItems[i].sip = (Int64)reader[0];
						_ipItems[i].eip = (Int64)reader[1];
						++i;
					}
					Debug.Assert(_lenOfiptable==i);				
					reader.Close();
				}catch(Exception ex)
				{
					_lenOfiptable = 0;
					_ipItems = null;
					throw ex;
				}
			}
		}
		
		// 返回ip地址所在的范围
		public IpPosition SearchIpPostion(String ip){
		
			Debug.Assert(IPAddress.Parse(ip)!=null);

			return SearchIpPostion( IPAddress.Parse(ip).Address );
		}
		
		public IpPosition SearchIpPostion(Int64 ip)
		{
			int index = SearchRangeOfStartIp(ip);
			if (-1==index) {
				return new IpPosition(-1,-1,"未知地址",String.Empty);
			}
			IpPosition ippos;
			using (SqlConnection conn=new SqlConnection(_connString))
			{
				SqlCommand cmd = conn.CreateCommand();
				cmd.CommandType = System.Data.CommandType.StoredProcedure;
				cmd.CommandText = SelIpPosRange;
				cmd.Parameters.Add("@startip",System.Data.SqlDbType.BigInt).Value=_ipItems[index].sip;
				conn.Open();
				
				SqlDataReader reader = 
					cmd.ExecuteReader(System.Data.CommandBehavior.SingleRow);
				Boolean has = reader.Read();
				Debug.Assert(has);
				ippos = new IpPosition(
					(Int64)reader[0]
					,(Int64)reader[1]
					,(reader[2]==System.DBNull.Value)?String.Empty:(String)reader[2]
					,(reader[3]==System.DBNull.Value)?String.Empty:(String)reader[3]);
				reader.Close();
			}

			return ippos;
		}
		
		// 检索指定的ip范围在IpTable中的位置 -1表示未知的位置
		public int SearchRangeOfStartIp(Int64 ip)
		{
			int a,b,m;
			Debug.Assert(_lenOfiptable>0);
			a = 0; b = _lenOfiptable;
			while (a<=b) {
				m=(a+b)>>1;
				if (ip>_ipItems[m].eip) {
					a = m+1;
				}else if(ip<_ipItems[m].sip)
				{
					b = m-1;
				}else{
					return m;
				}
			}
			return -1;
		}
		
		
		public	static IpLookTable Instance()
		{
			if(null==_theLookupTable)
			{
				_theLookupTable = new IpLookTable();
			}

			return _theLookupTable;
		}

		public IpRange[] Items{
			get{
				return _ipItems;
			}
		}
		private const String SelCounts = "select count(*) from ippos";
		private const String SelIpPosList = "select startip,endip from ippos order by startip";
		private const String SelIpPosRange = "SelIpPosRange";
		private String _connString;
		private IpRange[] _ipItems;	
		private int   _lenOfiptable = 0;
		private static IpLookTable _theLookupTable = null;
	}
}