高性能IP数据库格式详解 qqzeng-ip.dat

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高性能IP数据库格式详解 qqzeng-ip.dat

编码：UTF8 字节序：Little-Endian

返回多个字段信息（如：亚洲|中国|香港|九龙|油尖旺|新世界电讯|810200|Hong Kong|HK|114.17495|22.327115）

------------------------ 文件结构 ---------------------------

//文件头 16字节(4-4-4-4)
[索引区第一条流位置][索引区最后一条流位置][前缀区第一条的流位置][前缀区最后一条的流位置]

//内容区长度无限制
[地区信息][地区信息]……唯一不重复

//索引区 12字节(4-4-3-1)
[起始IP][结束IP][地区流位置][流长度]

//前缀区 9字节(1-4-4)
[0-255][索引区start索引][索引区end索引]

------------------------ 文件结构 ---------------------------

优势：索引区分为[起始IP][结束IP][地区偏移][长度],减少多级偏移跳转步骤和长度的解析,提高效率;
根据ip第一位字节作为前缀,解析出以这个数字为前缀的第一个索引和最后一个索引,缩小查询区间,
然后在这区间再用二分查找快速查找到对应区间,效率提高几个等级

压缩：原版txt为15M,生成这种dat结构为2.45M

性能：普通电脑测试,解析，100万ip耗时2.012439秒，1千万耗时21.10258秒，好点的电脑测试会更高效

对比：相比其他dat更简洁更高效

创建：qqzeng-ip 于 2015-08-01

public class IPSearch{    private Dictionary<uint, PrefixIndex> prefixDict;    private byte[] indexBuffer;    private byte[] data;    long firstStartIpOffset;//索引区第一条流位置    long lastStartIpOffset;//索引区最后一条流位置    long prefixStartOffset;//前缀区第一条的流位置    long prefixEndOffset;//前缀区最后一条的流位置    long ipCount;       //ip段数量    long prefixCount;  //前缀数量    /// <summary>    /// 初始化二进制dat数据    /// </summary>    /// <param name="dataPath"></param>    public IPSearch(string dataPath)    {        using (FileStream fs = new FileStream(dataPath, FileMode.Open, FileAccess.Read, FileShare.Read))        {            data = new byte[fs.Length];            fs.Read(data, 0, data.Length);        }        firstStartIpOffset = BytesToLong(data[0], data[1], data[2], data[3]);        lastStartIpOffset = BytesToLong(data[4], data[5], data[6], data[7]);        prefixStartOffset = BytesToLong(data[8], data[9], data[10], data[11]);        prefixEndOffset = BytesToLong(data[12], data[13], data[14], data[15]);        //prefixCount 不固定为256 方便以后自由定制 国内版  国外版 全球版 或者某部分 都可以        ipCount = (lastStartIpOffset - firstStartIpOffset) / 12 + 1; //索引区块每组 12字节                  prefixCount = (prefixEndOffset - prefixStartOffset) / 9 + 1; //前缀区块每组 9字节        //初始化前缀对应索引区区间        indexBuffer = new byte[prefixCount * 9];        Array.Copy(data, prefixStartOffset, indexBuffer, 0, prefixCount * 9);        prefixDict = new Dictionary<uint, PrefixIndex>();        for (var k = 0; k < prefixCount; k++)        {            int i = k * 9;            uint prefix = (uint)indexBuffer[i];            long start_index = BytesToLong(indexBuffer[i + 1], indexBuffer[i + 2], indexBuffer[i + 3], indexBuffer[i + 4]);            long end_index = BytesToLong(indexBuffer[i + 5], indexBuffer[i + 6], indexBuffer[i + 7], indexBuffer[i + 8]);            prefixDict.Add(prefix, new PrefixIndex() { prefix = prefix, start_index = start_index, end_index = end_index });        }    }    public static uint IpToInt(string ip)    {        byte[] bytes = IPAddress.Parse(ip).GetAddressBytes();        return (uint)bytes[3] + (((uint)bytes[2]) << 8) + (((uint)bytes[1]) << 16) + (((uint)bytes[0]) << 24);    }    public static string IntToIP(uint ip_Int)    {        return new IPAddress(ip_Int).ToString();    }    /// <summary>    /// 根据ip查询多维字段信息    /// </summary>    /// <param name="ip">ip地址（123.4.5.6）</param>    /// <returns>亚洲|中国|香港|九龙|油尖旺|新世界电讯|810200|Hong Kong|HK|114.17495|22.327115</returns>    public string Query(string ip)    {        uint intIP = IpToInt(ip);        uint high = 0;        uint low = 0;        uint startIp = 0;        uint endIp = 0;        uint local_offset = 0;        uint local_length = 0;        uint ip_prefix_value = uint.Parse(ip.Split('.')[0]);        if (prefixDict.ContainsKey(ip_prefix_value))        {            low = (uint)prefixDict[ip_prefix_value].start_index;            high = (uint)prefixDict[ip_prefix_value].end_index;        }        else        {            return "";        }        uint my_index = low == high? low : BinarySearch(low, high, intIP);                  GetIndex(my_index, out startIp, out endIp, out local_offset, out local_length);        if ((startIp <= intIP) && (endIp >= intIP))        {            return GetLocal(local_offset, local_length);        }        else        {            return "";        }    }    /// <summary>    /// 二分逼近算法    /// </summary>    public uint BinarySearch(uint low, uint high, uint k)    {        uint M = 0;        while (low <= high)        {            uint mid = (low + high) / 2;            uint endipNum = GetEndIp(mid);            if (endipNum >= k)            {                M = mid; //mid有可能是解                high = mid - 1;            }            else                low = mid + 1;        }        return M;    }    /// <summary>    /// 在索引区解析    /// </summary>    /// <param name="left">ip第left个索引</param>    /// <param name="startip">返回开始ip的数值</param>    /// <param name="endip">返回结束ip的数值</param>    /// <param name="local_offset">返回地址信息的流位置</param>    /// <param name="local_length">返回地址信息的流长度</param>    private void GetIndex(uint left, out uint startip, out uint endip, out uint local_offset, out uint local_length)    {        long left_offset = firstStartIpOffset + (left * 12);        startip = BytesToLong(data[left_offset], data[1 + left_offset], data[2 + left_offset],data[3 + left_offset]);        endip = BytesToLong(data[4+left_offset], data[5 + left_offset], data[6 + left_offset], data[7 + left_offset]);        local_offset = (uint)data[8 + left_offset] + (((uint)data[9 + left_offset]) << 8) + (((uint)data[10 + left_offset]) << 16);        local_length = (uint)data[11 + left_offset];    }    /// <summary>    /// 只获取结束ip的数值    /// </summary>    /// <param name="left">索引区第left个索引</param>    /// <returns>返回结束ip的数值</returns>    private uint GetEndIp(uint left)    {        long left_offset = firstStartIpOffset + (left * 12);        return BytesToLong(data[4 + left_offset], data[5 + left_offset], data[6 + left_offset], data[7 + left_offset]);    }    /// <summary>    /// 返回地址信息    /// </summary>    /// <param name="local_offset">地址信息的流位置</param>    /// <param name="local_length">地址信息的流长度</param>    /// <returns></returns>    private string GetLocal(uint local_offset, uint local_length)    {        byte[] buf = new byte[local_length];        Array.Copy(data, local_offset, buf, 0, local_length);        return Encoding.UTF8.GetString(buf, 0, (int)local_length);    }    /// <summary>    /// 字节转整形 小节序     /// </summary>    /// <param name="a"></param>    /// <param name="b"></param>    /// <param name="c"></param>    /// <param name="d"></param>    /// <returns></returns>    private uint BytesToLong(byte a, byte b, byte c, byte d)    {        return ((uint)a << 0) | ((uint)b << 8) | ((uint)c << 16) | ((uint)d << 24);    }}/*（调用例子）：IPSearch finder = new IPSearch("qqzeng-ip.dat");string result = finder.Query("1.2.3.4");--> result="亚洲|中国|香港|九龙|油尖旺|新世界电讯|810200|Hong Kong|HK|114.17495|22.327115"*/public class PrefixIndex{    public uint prefix { get; set; }    public long start_index { get; set; }    public long end_index { get; set; }}

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