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feat: 增加 IPv6 算法支持

This commit is contained in:
Argo Zhang 2025-11-20 15:22:21 +08:00
parent 4f39707beb
commit 499e091761
1 changed files with 84 additions and 32 deletions
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116
binding/csharp/IP2Region.Net/XDB/Searcher.cs
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@ -9,7 +9,6 @@ using IP2Region.Net.Internal;
using IP2Region.Net.Internal.Abstractions;
using System.Buffers.Binary;
using System.Net;
using System.Runtime.InteropServices;
using System.Text;
namespace IP2Region.Net.XDB;
@ -17,6 +16,7 @@ namespace IP2Region.Net.XDB;
public class Searcher : ISearcher
{
private readonly AbstractCacheStrategy _cacheStrategy;
public int IoCount => _cacheStrategy.IoCount;
public Searcher(CachePolicy cachePolicy, string dbPath)
@ -27,56 +27,108 @@ public class Searcher : ISearcher
public string? Search(string ipStr)
{
var ip = Util.IpAddressToUInt32(ipStr);
return Search(ip);
var ipAddress = IPAddress.Parse(ipStr);
return Search(ipAddress);
}
public string? Search(IPAddress ipAddress)
{
var ip = Util.IpAddressToUInt32(ipAddress);
return Search(ip);
return SearchCore(ipAddress.GetAddressBytes());
}
public string? Search(uint ip)
public string? Search(uint ipAddress)
{
var version = new Version() { Length = 4, IndexSize = 14 };
var index = _cacheStrategy.GetVectorIndex(ip);
uint sPtr = MemoryMarshal.Read<uint>(index.Span);
uint ePtr = MemoryMarshal.Read<uint>(index.Span.Slice(4));
var bytes = BitConverter.GetBytes(ipAddress);
bytes.Reverse();
return SearchCore(bytes);
}
uint dataLen = 0;
uint dataPtr = 0;
uint l = 0;
uint h = (ePtr - sPtr) / (uint)version.IndexSize;
string? SearchCore(byte[] ipBytes)
{
// 每个 vector 索引项的字节数
var vectorIndexSize = 8;
while (l <= h)
// vector 索引的列数
var vectorIndexCols = 256;
// 计算得到 vector 索引项的开始地址。
var il0 = ipBytes[0];
var il1 = ipBytes[1];
var idx = il0 * vectorIndexCols * vectorIndexSize + il1 * vectorIndexSize;
var data = _cacheStrategy.GetData(256 + idx, vectorIndexSize);
var sPtr = BinaryPrimitives.ReadUInt32LittleEndian(data.Span);
var ePtr = BinaryPrimitives.ReadUInt32LittleEndian(data.Span[4..]);
var length = ipBytes.Length;
var indexSize = length * 2 + 6;
var l = 0;
var h = (ePtr - sPtr) / indexSize;
var dataLen = 0;
long dataPtr = 0;
while (l < h)
{
var mid = Util.GetMidIp(l, h);
var pos = sPtr + mid * version.IndexSize;
var buffer = _cacheStrategy.GetData((int)pos, version.IndexSize);
int m = (int)(l + h) >> 1;
if (ip < version.GetVectorIndexStartPos(buffer))
var p = (int)sPtr + m * indexSize;
var buff = _cacheStrategy.GetData(p, indexSize);
var s = buff.Span[..length];
var e = buff.Span.Slice(length, length);
if (ByteCompare(ipBytes, s) == -1)
{
h = mid - 1;
h = m - 1;
}
else if (ip > version.GetVectorIndexEndPos(buffer))
else if (ByteCompare(ipBytes, e) == 1)
{
l = mid + 1;
l = m + 1;
}
else
{
dataLen = BinaryPrimitives.ReadUInt16LittleEndian(buffer.Span.Slice(8));
dataPtr = BinaryPrimitives.ReadUInt32LittleEndian(buffer.Span.Slice(10));
dataLen = BinaryPrimitives.ReadUInt16LittleEndian(buff.Span.Slice(length * 2, 2));
dataPtr = BinaryPrimitives.ReadUInt32LittleEndian(buff.Span[(length * 2 + 2)..]);
break;
}
}
if (dataLen == 0)
{
return default;
}
var regionBuff = _cacheStrategy.GetData((int)dataPtr, (int)dataLen);
return Encoding.UTF8.GetString(regionBuff.Span.ToArray());
var regionBuff = _cacheStrategy.GetData((int)dataPtr, dataLen);
return Encoding.UTF8.GetString(regionBuff.Span);
}
}
static int ByteCompare(byte[] ip1, ReadOnlySpan<byte> ip2) => ip1.Length == 4 ? IPv4Compare(ip1, ip2) : IPv6Compare(ip1, ip2);
static int IPv4Compare(byte[] ip1, ReadOnlySpan<byte> ip2)
{
var ret = 0;
for (int i = 0; i < ip1.Length; i++)
{
if (ip1[i] < ip2[ip1.Length - 1 - i])
{
return -1;
}
else if (ip1[i] > ip2[ip1.Length - 1 - i])
{
return 1;
}
}
return ret;
}
static int IPv6Compare(byte[] ip1, ReadOnlySpan<byte> ip2)
{
var ret = 0;
for (int i = 0; i < ip1.Length; i++)
{
if (ip1[i] < ip2[i])
{
return -1;
}
else if (ip1[i] > ip2[i])
{
return 1;
}
}
return ret;
}
}