feat(csharp): 2.0 xdb csharp client implementation

binding/csharp/IP2Region.Net.BenchMark/IP2Region.Net.BenchMark.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net6.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="BenchmarkDotNet" Version="0.13.2" />
+      <PackageReference Include="BenchmarkDotNet.Annotations" Version="0.13.2" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\IP2Region.Net\IP2Region.Net.csproj" />
+    </ItemGroup>
+
+</Project>

binding/csharp/IP2Region.Net.BenchMark/Program.cs

+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Running;
+using IP2Region.Net.XDB;
+
+BenchmarkRunner.Run(typeof(Program).Assembly);
+
+public class CachePolicyCompare
+{
+    private readonly Searcher _contentSearcher = new Searcher(CachePolicy.Content);
+    private readonly Searcher _vectorSearcher = new Searcher(CachePolicy.VectorIndex);
+
+    private readonly string _testIpAddress = "114.114.114.114";
+
+    [Benchmark]
+    [BenchmarkCategory(nameof(CachePolicy.Content))]
+    public void CachePolicy_Content() => _contentSearcher.Search(_testIpAddress);
+
+    [Benchmark]
+    [BenchmarkCategory(nameof(CachePolicy.VectorIndex))]
+    public void CachePolicy_VectorIndex() => _vectorSearcher.Search(_testIpAddress);
+}
\ No newline at end of file

binding/csharp/IP2Region.Net.Test/IP2Region.Net.Test.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
+    <PackageReference Include="NUnit.Analyzers" Version="3.3.0" />
+    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\IP2Region.Net\IP2Region.Net.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="TestData" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="TestData\ip.merge.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

binding/csharp/IP2Region.Net.Test/SearcherTest.cs

+using IP2Region.Net.XDB;
+
+namespace IP2Region.Net.Test;
+
+[TestFixture]
+public class SearcherTest
+{
+    public static IEnumerable<string> Ips()
+    {
+        yield return "114.114.114.114";
+        yield return "119.29.29.29";
+        yield return "223.5.5.5";
+        yield return "180.76.76.76";
+        yield return "8.8.8.8";
+    }
+
+    [TestCaseSource(nameof(Ips))]
+    public void TestSearchCacheContent(string ip)
+    {
+        var contentSearcher = new Searcher(CachePolicy.Content);
+        var region = contentSearcher.Search(ip);
+        Console.WriteLine(region);
+    }
+
+    [TestCaseSource(nameof(Ips))]
+    public void TestSearchCacheVector(string ip)
+    {
+        var vectorSearcher = new Searcher(CachePolicy.VectorIndex);
+        var region = vectorSearcher.Search(ip);
+        Console.WriteLine(region);
+    }
+
+    [TestCaseSource(nameof(Ips))]
+    public void TestSearchCacheFile(string ip)
+    {
+        var fileSearcher = new Searcher(CachePolicy.File);
+        var region = fileSearcher.Search(ip);
+        Console.WriteLine(region);
+    }
+
+    [TestCase(CachePolicy.Content)]
+    [TestCase(CachePolicy.VectorIndex)]
+    [TestCase(CachePolicy.File)]
+    public void TestBenchSearch(CachePolicy cachePolicy)
+    {
+        Searcher searcher = new Searcher(cachePolicy);
+        var srcPath = Path.Combine(AppContext.BaseDirectory, "TestData", "ip.merge.txt");
+
+        foreach (var line in File.ReadLines(srcPath))
+        {
+            var ps = line.Trim().Split("|", 3);
+
+            if (ps.Length != 3)
+            {
+                throw new ArgumentException($"invalid ip segment line {line}", nameof(line));
+            }
+
+            var sip = Util.IpAddressToUInt32(ps[0]);
+            var eip = Util.IpAddressToUInt32(ps[1]);
+            var mip = Util.GetMidIp(sip, eip);
+
+            uint[] temp = { sip, Util.GetMidIp(sip, mip), mip, Util.GetMidIp(mip, eip), eip };
+
+            foreach (var ip in temp)
+            {
+                var region = searcher.Search(ip);
+
+                if (region != ps[2])
+                {
+                    throw new Exception($"failed search {ip} with ({region}!={ps[2]})");
+                }
+            }
+        }
+    }
+}
\ No newline at end of file

binding/csharp/IP2Region.Net.Test/Usings.cs

+global using NUnit.Framework;
\ No newline at end of file

binding/csharp/IP2Region.Net.Test/UtilTest.cs

+using IP2Region.Net.XDB;
+
+namespace IP2Region.Net.Test;
+
+[TestFixture]
+public class UtilTest
+{
+    [TestCase("114.114.114.114")]
+    public void TestIpAddressToUInt32(string value)
+    {
+        var uintIp = XDB.Util.IpAddressToUInt32(value);
+        Console.WriteLine(uintIp);
+    }
+}
\ No newline at end of file

binding/csharp/IP2Region.Net/IP2Region.Net.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <id>IP2Region.Net</id>
+        <version>1.0.2</version>
+        <title>IP2Region.Net</title>
+        <authors>Alan Lee</authors>
+        <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
+        <PackageReadmeFile>README.md</PackageReadmeFile>
+        <PackageProjectUrl>https://github.com/lionsoul2014/ip2region/tree/master/binding/csharp</PackageProjectUrl>
+        <RepositoryUrl>https://github.com/lionsoul2014/ip2region/tree/master/binding/csharp</RepositoryUrl>
+        <Description>ip2region 是一个离线IP地址定位库，极速响应，微秒级查询</Description>
+        <tags>IP2Region</tags>
+
+
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+        <TargetFrameworks>net6.0;netstandard2.1</TargetFrameworks>
+        <LangVersion>10.0</LangVersion>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <Folder Include="Data" />
+    </ItemGroup>
+
+    <ItemGroup>
+        <None Update="Data\ip2region.xdb">
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+        </None>
+        <None Include="..\README.md" Pack="true" PackagePath="\" />
+    </ItemGroup>
+
+</Project>

binding/csharp/IP2Region.Net/XDB/CachePolicy.cs

+namespace IP2Region.Net.XDB;
+
+public enum CachePolicy
+{
+    /// <summary>
+    /// no cache , not thread safe!
+    /// </summary>
+    File,
+    /// <summary>
+    /// cache vector index , reduce the number of IO operations , not thread safe!
+    /// </summary>
+    VectorIndex,
+    /// <summary>
+    /// default cache policy , cache whole xdb file , thread safe 
+    /// </summary>
+    Content
+}
\ No newline at end of file

binding/csharp/IP2Region.Net/XDB/ISearcher.cs

+using System.Net;
+
+namespace IP2Region.Net.XDB;
+
+public interface ISearcher
+{
+    string? Search(string ipStr);
+
+    string? Search(IPAddress ipAddress);
+
+    string? Search(uint ipAddress);
+
+    int IoCount { get; }
+}
\ No newline at end of file

binding/csharp/IP2Region.Net/XDB/Searcher.cs

+// Copyright 2022 The Ip2Region Authors. All rights reserved.
+// Use of this source code is governed by a Apache2.0-style
+// license that can be found in the LICENSE file.
+// @Author Alan Lee <lzh.shap@gmail.com>
+// @Date   2022/09/06
+
+using System.Net;
+using System.Text;
+
+namespace IP2Region.Net.XDB;
+
+public class Searcher : ISearcher
+{
+    const int HeaderInfoLength = 256;
+    const int VectorIndexRows = 256;
+    const int VectorIndexCols = 256;
+    const int VectorIndexSize = 8;
+    const int SegmentIndexSize = 14;
+
+    private readonly byte[]? _vectorIndex;
+    private readonly byte[]? _contentBuff;
+    private readonly FileStream _contentStream;
+    private readonly CachePolicy _cachePolicy;
+    public int IoCount { get; private set; }
+
+    public Searcher(CachePolicy cachePolicy = CachePolicy.Content, string? dbPath = null)
+    {
+        if (string.IsNullOrEmpty(dbPath))
+        {
+            dbPath = Path.Combine(AppContext.BaseDirectory, "Data", "ip2region.xdb");
+        }
+
+        _contentStream = File.OpenRead(dbPath);
+        _cachePolicy = cachePolicy;
+
+        switch (_cachePolicy)
+        {
+            case CachePolicy.Content:
+                using (var stream = new MemoryStream())
+                {
+                    _contentStream.CopyTo(stream);
+                    _contentBuff = stream.ToArray();
+                }
+
+                break;
+            case CachePolicy.VectorIndex:
+                var vectorLength = VectorIndexRows * VectorIndexCols * VectorIndexSize;
+                _vectorIndex = new byte[vectorLength];
+                Read(HeaderInfoLength, _vectorIndex);
+                break;
+        }
+    }
+
+    ~Searcher()
+    {
+        _contentStream.Close();
+        _contentStream.Dispose();
+    }
+
+    public string? Search(string ipStr)
+    {
+        var ip = Util.IpAddressToUInt32(ipStr);
+        return Search(ip);
+    }
+
+    public string? Search(IPAddress ipAddress)
+    {
+        var ip = Util.IpAddressToUInt32(ipAddress);
+        return Search(ip);
+    }
+
+    public string? Search(uint ip)
+    {
+        var il0 = ip >> 24 & 0xFF;
+        var il1 = ip >> 16 & 0xFF;
+        var idx = il0 * VectorIndexCols * VectorIndexSize + il1 * VectorIndexSize;
+
+        uint sPtr = 0, ePtr = 0;
+
+        switch (_cachePolicy)
+        {
+            case CachePolicy.VectorIndex:
+                sPtr = BitConverter.ToUInt32(_vectorIndex.AsSpan()[(int)idx..]);
+                ePtr = BitConverter.ToUInt32(_vectorIndex.AsSpan()[((int)idx + 4)..]);
+                break;
+            case CachePolicy.Content:
+                sPtr = BitConverter.ToUInt32(_contentBuff.AsSpan()[(HeaderInfoLength + (int)idx)..]);
+                ePtr = BitConverter.ToUInt32(_contentBuff.AsSpan()[(HeaderInfoLength + (int)idx + 4)..]);
+                break;
+            case CachePolicy.File:
+                var buff = new byte[VectorIndexSize];
+                Read((int)(idx + HeaderInfoLength), buff);
+                sPtr = BitConverter.ToUInt32(buff);
+                ePtr = BitConverter.ToUInt32(buff.AsSpan()[4..]);
+                break;
+        }
+
+
+        var dataLen = 0;
+        uint dataPtr = 0;
+        var l = 0;
+        var h = (int)((ePtr - sPtr) / SegmentIndexSize);
+        var buffer = new byte[SegmentIndexSize];
+
+        while (l <= h)
+        {
+            var mid = Util.GetMidIp(l, h);
+            var pos = sPtr + mid * SegmentIndexSize;
+
+            Read((int)pos, buffer);
+            var sip = BitConverter.ToUInt32(buffer);
+
+            if (ip < sip)
+            {
+                h = mid - 1;
+            }
+            else
+            {
+                var eip = BitConverter.ToUInt32(buffer.AsSpan()[4..]);
+                if (ip > eip)
+                {
+                    l = mid + 1;
+                }
+                else
+                {
+                    dataLen = BitConverter.ToUInt16(buffer.AsSpan()[8..]);
+                    dataPtr = BitConverter.ToUInt32(buffer.AsSpan()[10..]);
+                    break;
+                }
+            }
+        }
+
+        if (dataLen == 0)
+        {
+            return default;
+        }
+
+        var regionBuff = new byte[dataLen];
+        Read((int)dataPtr, regionBuff);
+        return Encoding.UTF8.GetString(regionBuff);
+    }
+
+    private void Read(int offset, byte[] buff)
+    {
+        switch (_cachePolicy)
+        {
+            case CachePolicy.Content:
+                _contentBuff.AsSpan()[offset..(offset + buff.Length)].CopyTo(buff);
+                break;
+            default:
+                _contentStream.Seek(offset, SeekOrigin.Begin);
+                IoCount++;
+
+                var rLen = _contentStream.Read(buff);
+                if (rLen != buff.Length)
+                {
+                    throw new IOException($"incomplete read: readed bytes should be {buff.Length}");
+                }
+
+                break;
+        }
+    }
+}
\ No newline at end of file

binding/csharp/IP2Region.Net/XDB/Util.cs

+using System.Net;
+
+namespace IP2Region.Net.XDB;
+
+public static class Util
+{
+    public static uint IpAddressToUInt32(string ipAddress)
+    {
+        var address = IPAddress.Parse(ipAddress);
+        return IpAddressToUInt32(address);
+    }
+    
+    public static uint IpAddressToUInt32(IPAddress ipAddress)
+    {
+        byte[] bytes = ipAddress.GetAddressBytes();
+        Array.Reverse(bytes);
+        return BitConverter.ToUInt32(bytes, 0);
+    }
+
+    public static uint GetMidIp(uint x, uint y)
+        => (x & y) + ((x ^ y) >> 1);
+
+    public static int GetMidIp(int x, int y)
+        => (x & y) + ((x ^ y) >> 1);
+}
\ No newline at end of file

binding/csharp/IP2Region.SearchTest/App.config

-<?xml version="1.0" encoding="utf-8" ?>
-<configuration>
-    <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
-    </startup>
-</configuration>
\ No newline at end of file

binding/csharp/IP2Region.SearchTest/IP2Region.SearchTest.csproj

-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <ProjectGuid>{FF136AEA-D41F-4C14-842B-CE597BB97916}</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>IP2Region.SearchTest</RootNamespace>
-    <AssemblyName>IP2Region.SearchTest</AssemblyName>
-    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
-    <FileAlignment>512</FileAlignment>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Deterministic>true</Deterministic>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <ErrorReport>prompt</ErrorReport>
-    <WarningLevel>4</WarningLevel>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Xml.Linq" />
-    <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="Microsoft.CSharp" />
-    <Reference Include="System.Data" />
-    <Reference Include="System.Net.Http" />
-    <Reference Include="System.Xml" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="Program.cs" />
-    <Compile Include="Properties\AssemblyInfo.cs" />
-  </ItemGroup>
-  <ItemGroup>
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\IP2Region\IP2Region.csproj">
-      <Project>{483575a5-ffb3-4131-a2dc-6d3ad3bb268f}</Project>
-      <Name>IP2Region</Name>
-    </ProjectReference>
-  </ItemGroup>
-  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-</Project>
\ No newline at end of file

binding/csharp/IP2Region.SearchTest/Program.cs

-using IP2Region.xdb;
-using System;
-using System.Diagnostics;
-using System.IO;
-
-namespace IP2Region.SearchTest
-{
-    internal class Program
-    {
-
-        public static void PrintHelp(String[] args)
-        {
-            Console.WriteLine("ip2region xdb searcher");
-            Console.WriteLine("IP2Region.SearchTest.exe [command] [command options]");
-            Console.WriteLine("Command: ");
-            Console.WriteLine("  search    search input test");
-            Console.WriteLine("  bench     search bench test");
-        }
-        public static Searcher CreateSearcher(String dbPath, String cachePolicy)
-        {
-            if ("file" == cachePolicy)
-            {
-                return Searcher.NewWithFileOnly(dbPath);
-            }
-            else if ("vectorIndex" == cachePolicy)
-            {
-                byte[] vIndex = Searcher.LoadVectorIndexFromFile(dbPath);
-                return Searcher.NewWithVectorIndex(dbPath, vIndex);
-            }
-            else if ("content" == cachePolicy)
-            {
-                byte[] cBuff = Searcher.LoadContentFromFile(dbPath);
-                return Searcher.NewWithBuffer(cBuff);
-            }
-            else
-            {
-                throw new Exception("invalid cache policy `" + cachePolicy + "`, options: file/vectorIndex/content");
-            }
-        }
-
-        public static void SearchTest(string[] args)
-        {
-            String dbPath = "", cachePolicy = "vectorIndex";
-            foreach (string r in args)
-            {
-                if (r.Length < 5)
-                {
-                    continue;
-                }
-
-                if (r.IndexOf("--") != 0)
-                {
-                    continue;
-                }
-
-                int sIdx = r.IndexOf('=');
-                if (sIdx < 0)
-                {
-                    Console.WriteLine("missing = for args pair `{0}`", r);
-                    return;
-                }
-
-                String key = r.Substring(2, sIdx - 2);
-                String val = r.Substring(sIdx + 1);
-                // Console.WriteLinef("key=%s, val=%s\n", key, val);
-                if ("db" == key)
-                {
-                    dbPath = val;
-                }
-                else if ("cache-policy" == key)
-                {
-                    cachePolicy = val;
-                }
-                else
-                {
-                    Console.WriteLine("undefined option `{0}`", r);
-                    return;
-                }
-            }
-
-            if (dbPath.Length < 1)
-            {
-                Console.WriteLine("IP2Region.SearchTest.exe search [command options]");
-                Console.WriteLine("options:");
-                Console.WriteLine(" --db string              ip2region binary xdb file path");
-                Console.WriteLine(" --cache-policy string    cache policy: file/vectorIndex/content");
-                return;
-            }
-
-            Searcher searcher = CreateSearcher(dbPath, cachePolicy);
-
-            Console.WriteLine("ip2region xdb searcher test program, cachePolicy: {0}\ntype 'quit' to exit", cachePolicy);
-            while (true)
-            {
-                Console.Write("ip2region>> ");
-                var line = Console.ReadLine().Trim();
-                if (line.Length < 2) continue;
-                if (line == "quit") break;
-                try
-                {
-                    var st = new Stopwatch();
-                    st.Start();
-                    var region = searcher.Search(line);
-                    st.Stop();
-                    var cost = st.ElapsedMilliseconds;
-                    Console.WriteLine("{{region: {0}, ioCount: {1}, took: {2} ms}}", region, searcher.IOCount, cost);
-                }
-                catch (Exception e)
-                {
-                    Console.WriteLine("{{err:{0}, ioCount: {1}}}", e, searcher.IOCount);
-                }
-            }
-            Console.WriteLine("searcher test program exited, thanks for trying");
-
-        }
-        public static void BenchTest(String[] args)
-        {
-            String dbPath = "", srcPath = "", cachePolicy = "vectorIndex";
-            foreach (String r in args)
-            {
-                if (r.Length < 5)
-                {
-                    continue;
-                }
-
-                if (r.IndexOf("--") != 0)
-                {
-                    continue;
-                }
-
-                int sIdx = r.IndexOf('=');
-                if (sIdx < 0)
-                {
-                    Console.WriteLine("missing = for args pair `{0}`", r);
-                    return;
-                }
-
-                String key = r.Substring(2, sIdx - 2);
-                String val = r.Substring(sIdx + 1);
-                if ("db" == key)
-                {
-                    dbPath = val;
-                }
-                else if ("src" == key)
-                {
-                    srcPath = val;
-                }
-                else if ("cache-policy" == key)
-                {
-                    cachePolicy = val;
-                }
-                else
-                {
-                    Console.WriteLine("undefined option `{0}`", r);
-                    return;
-                }
-            }
-
-            if (dbPath.Length < 1 || srcPath.Length < 1)
-            {
-                Console.WriteLine("IP2Region.SearchTest.exe bench [command options]");
-                Console.WriteLine("options:");
-                Console.WriteLine(" --db string              ip2region binary xdb file path");
-                Console.WriteLine(" --src string             source ip text file path");
-                Console.WriteLine(" --cache-policy string    cache policy: file/vectorIndex/content");
-                return;
-            }
-
-            Searcher searcher = CreateSearcher(dbPath, cachePolicy);
-            long count = 0;
-            var sw = new Stopwatch();
-            var lines = File.ReadAllLines(srcPath);
-            foreach (var line in lines)
-            {
-                String l = line.Trim();
-                String[] ps = l.Split(new[] { '|' }, 3);
-                if (ps.Length != 3)
-                {
-                    Console.WriteLine("invalid ip segment `{0}`", l);
-                    return;
-                }
-                long sip;
-                try
-                {
-                    sip = Searcher.checkIP(ps[0]);
-                }
-                catch (Exception e)
-                {
-                    Console.WriteLine("check start ip `{0}`: {1}", ps[0], e);
-                    return;
-                }
-                long eip;
-                try
-                {
-                    eip = Searcher.checkIP(ps[1]);
-                }
-                catch (Exception e)
-                {
-                    Console.WriteLine("check end ip `{0}`: {1}", ps[1], e);
-                    return;
-                }
-
-                if (sip > eip)
-                {
-                    Console.WriteLine("start ip({0}) should not be greater than end ip({1})", ps[0], ps[1]);
-                    return;
-                }
-
-                long mip = (sip + eip) >> 1;
-                foreach (var ip in new long[] { sip, (sip + mip) >> 1, mip, (mip + eip) >> 1, eip })
-                {
-                    sw.Start();
-                    String region = searcher.Search(ip);
-                    sw.Stop();
-                    // check the region info
-                    if (ps[2] != (region))
-                    {
-                        Console.WriteLine("failed search({0}) with ({1} != {2})\n", Searcher.Long2ip(ip), region, ps[2]);
-                        return;
-                    }
-
-                    count++;
-                }
-            }
-
-            Console.WriteLine("Bench finished, {{cachePolicy: {0}, total: {1}, took: {2}, cost: {3} ms/op}}",
-                    cachePolicy, count, sw.Elapsed,
-                    count == 0 ? 0 : sw.ElapsedMilliseconds / count);
-        }
-        static void Main(string[] args)
-        {
-            if (args.Length < 1)
-            {
-                PrintHelp(args);
-                return;
-            }
-            switch (args[0])
-            {
-                case "search":
-                    try
-                    {
-                        SearchTest(args);
-                    }
-                    catch (Exception e)
-                    {
-                        Console.WriteLine("failed running search test: {0}", e);
-                    }
-                    break;
-                case "bench":
-                    try
-                    {
-                        BenchTest(args);
-                    }
-                    catch (Exception e)
-                    {
-                        Console.WriteLine("failed running bench test: {0}", e);
-                    }
-                    break;
-                default: PrintHelp(args); break;
-            }
-        }
-    }
-}

binding/csharp/IP2Region.SearchTest/Properties/AssemblyInfo.cs

-using System.Reflection;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-
-// 有关程序集的一般信息由以下
-// 控制。更改这些特性值可修改
-// 与程序集关联的信息。
-[assembly: AssemblyTitle("IP2Region.SearchTest")]
-[assembly: AssemblyDescription("")]
-[assembly: AssemblyConfiguration("")]
-[assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("IP2Region.SearchTest")]
-[assembly: AssemblyCopyright("Copyright ©  2022")]
-[assembly: AssemblyTrademark("")]
-[assembly: AssemblyCulture("")]
-
-// 将 ComVisible 设置为 false 会使此程序集中的类型
-//对 COM 组件不可见。如果需要从 COM 访问此程序集中的类型
-//请将此类型的 ComVisible 特性设置为 true。
-[assembly: ComVisible(false)]
-
-// 如果此项目向 COM 公开，则下列 GUID 用于类型库的 ID
-[assembly: Guid("ff136aea-d41f-4c14-842b-ce597bb97916")]
-
-// 程序集的版本信息由下列四个值组成: 
-//
-//      主版本
-//      次版本
-//      生成号
-//      修订号
-//
-//可以指定所有这些值，也可以使用“生成号”和“修订号”的默认值
-//通过使用 "*"，如下所示:
-// [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.0.0.0")]
-[assembly: AssemblyFileVersion("1.0.0.0")]

binding/csharp/IP2Region.sln

-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.1.32228.430
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "IP2Region", "IP2Region\IP2Region.csproj", "{483575A5-FFB3-4131-A2DC-6D3AD3BB268F}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "IP2Region.SearchTest", "IP2Region.SearchTest\IP2Region.SearchTest.csproj", "{FF136AEA-D41F-4C14-842B-CE597BB97916}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{483575A5-FFB3-4131-A2DC-6D3AD3BB268F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{483575A5-FFB3-4131-A2DC-6D3AD3BB268F}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{483575A5-FFB3-4131-A2DC-6D3AD3BB268F}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{483575A5-FFB3-4131-A2DC-6D3AD3BB268F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{FF136AEA-D41F-4C14-842B-CE597BB97916}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{FF136AEA-D41F-4C14-842B-CE597BB97916}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{FF136AEA-D41F-4C14-842B-CE597BB97916}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{FF136AEA-D41F-4C14-842B-CE597BB97916}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {6AEA440B-0D90-4F6E-BA9A-D42B27A78D7B}
-	EndGlobalSection
-EndGlobal

binding/csharp/IP2Region/IP2Region.csproj

-<Project Sdk="Microsoft.NET.Sdk">
-
-	<PropertyGroup>
-		<TargetFrameworks>netstandard2.0;netcoreapp3.1;net5.0;net6.0</TargetFrameworks>
-	</PropertyGroup>
-
-</Project>

binding/csharp/IP2Region/xdb/Header.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace IP2Region.xdb
-{
-    public class Header
-    {
-        public int Version { get; }
-        public int IndexPolicy { get; }
-        public int CreatedAt { get; }
-        public int StartIndexPtr { get; }
-        public int EndIndexPtr { get; }
-        public byte[] Buffer { get; }
-        public Header(byte[] buff)
-        {
-            if (buff == null) throw new ArgumentNullException(nameof(buff));
-            if (buff.Length < 16) throw new ArgumentOutOfRangeException(nameof(buff));
-            Version = Searcher.GetInt2(buff, 0);
-            IndexPolicy = Searcher.GetInt2(buff, 2);
-            CreatedAt = Searcher.GetInt(buff, 4);
-            StartIndexPtr = Searcher.GetInt(buff, 8);
-            EndIndexPtr = Searcher.GetInt(buff, 12);
-            Buffer = buff;
-
-        }
-        public override string ToString()
-        {
-            return "{" +
-            "Version: " + Version + ',' +
-            "IndexPolicy: " + IndexPolicy + ',' +
-            "CreatedAt: " + CreatedAt + ',' +
-            "StartIndexPtr: " + StartIndexPtr + ',' +
-            "EndIndexPtr: " + EndIndexPtr +
-        '}';
-        }
-    }
-}

binding/csharp/IP2Region/xdb/Searcher.cs

-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace IP2Region.xdb
-{
-    public class Searcher
-    {
-
-        // constant defined copied from the xdb maker
-        public static int HeaderInfoLength = 256;
-        public static int VectorIndexRows = 256;
-        public static int VectorIndexCols = 256;
-        public static int VectorIndexSize = 8;
-        public static int SegmentIndexSize = 14;
-
-        // random access file handle for file based search
-        private readonly Stream handle;
-
-        private int ioCount = 0;
-
-        public int IOCount => this.ioCount;
-
-
-        // vector index.
-        // use the byte[] instead of VectorIndex entry array to keep
-        // the minimal memory allocation.
-        private readonly byte[] vectorIndex;
-
-        // xdb content buffer, used for in-memory search
-        private readonly byte[] contentBuff;
-
-
-        // --- static method to create searchers
-
-
-        public static Searcher NewWithFileOnly(String dbPath)
-        {
-            return new Searcher(dbPath, null, null);
-        }
-
-        public static Searcher NewWithVectorIndex(String dbPath, byte[] vectorIndex)
-        {
-            return new Searcher(dbPath, vectorIndex, null);
-        }
-
-        public static Searcher NewWithBuffer(byte[] cBuff)
-        {
-            return new Searcher(null, null, cBuff);
-        }
-
-        // --- End of creator
-        public Searcher(string dbFile, byte[] vectorIndex, byte[] cBuff)
-        {
-            if (cBuff != null)
-            {
-                this.handle = null;
-                this.vectorIndex = null;
-                this.contentBuff = cBuff;
-            }
-            else
-            {
-                this.handle = File.OpenRead(dbFile);
-                this.vectorIndex = vectorIndex;
-                this.contentBuff = null;
-            }
-        }
-
-        public void Close()
-        {
-            if (this.handle != null) this.handle.Close();
-        }
-
-        public string Search(string ipStr)
-        {
-            var ip = checkIP(ipStr);
-            return Search(ip);
-        }
-
-        public string Search(long ip)
-        {
-            // reset the global counter
-            this.ioCount = 0;
-            // locate the segment index block based on the vector index
-            int sPtr = 0, ePtr = 0;
-            int il0 = (int)((ip >> 24) & 0xFF);
-            int il1 = (int)((ip >> 16) & 0xFF);
-            int idx = il0 * VectorIndexCols * VectorIndexSize + il1 * VectorIndexSize;
-            if (vectorIndex != null)
-            {
-                sPtr = GetInt(vectorIndex, idx);
-                ePtr = GetInt(vectorIndex, idx + 4);
-            }
-            else if (contentBuff != null)
-            {
-                sPtr = GetInt(contentBuff, HeaderInfoLength + idx);
-                ePtr = GetInt(contentBuff, HeaderInfoLength + idx + 4);
-            }
-            else
-            {
-                byte[] vectorBuff = new byte[VectorIndexSize];
-                Read(HeaderInfoLength + idx, vectorBuff);
-                sPtr = GetInt(vectorBuff, 0);
-                ePtr = GetInt(vectorBuff, 4);
-            }
-
-            // binary search the segment index block to get the region info
-            byte[] buff = new byte[SegmentIndexSize];
-            int dataLen = -1, dataPtr = -1;
-            int l = 0, h = (ePtr - sPtr) / SegmentIndexSize;
-            while (l <= h)
-            {
-                int m = (l + h) >> 1;
-                int p = sPtr + m * SegmentIndexSize;
-
-                // read the segment index
-                Read(p, buff);
-                long sip = GetIntLong(buff, 0);
-                if (ip < sip)
-                {
-                    h = m - 1;
-                }
-                else
-                {
-                    long eip = GetIntLong(buff, 4);
-                    if (ip > eip)
-                    {
-                        l = m + 1;
-                    }
-                    else
-                    {
-                        dataLen = GetInt2(buff, 8);
-                        dataPtr = GetInt(buff, 10);
-                        break;
-                    }
-                }
-            }
-
-            // empty match interception
-            // System.out.printf("dataLen: %d, dataPtr: %d\n", dataLen, dataPtr);
-            if (dataPtr < 0) return null;
-
-            // load and return the region data
-            byte[] regionBuff = new byte[dataLen];
-            Read(dataPtr, regionBuff);
-            //return new String(regionBuff, "utf-8");
-            return Encoding.UTF8.GetString(regionBuff);
-        }
-
-        protected virtual void Read(int offset, byte[] buffer)
-        {
-            // check the in-memory buffer first
-            if (contentBuff != null)
-            {
-                // @TODO: reduce data copying, directly decode the data ?
-                //System.arraycopy(contentBuff, offset, buffer, 0, buffer.length);
-                Array.Copy(contentBuff, offset, buffer, 0, buffer.Length);
-                return;
-            }
-
-            // read from the file handle
-            if (handle == null) throw new ArgumentNullException(nameof(handle));
-            handle.Seek(offset, SeekOrigin.Begin);
-
-            this.ioCount++;
-            var rLen = handle.Read(buffer, 0, buffer.Length);
-            if (rLen != buffer.Length) throw new IOException("incomplete read: read bytes should be " + buffer.Length);
-        }
-
-        // --- static cache util function
-        public static Header LoadHeader(Stream stream)
-        {
-            stream.Seek(0, SeekOrigin.Begin);
-            var buffer = new byte[HeaderInfoLength];
-            stream.Read(buffer, 0, HeaderInfoLength);
-            return new Header(buffer);
-        }
-        public static Header LoadHeaderFromFile(string dbPath)
-        {
-            using (var fs = File.OpenRead(dbPath)) return LoadHeader(fs);
-        }
-        public static byte[] LoadVectorIndex(Stream stream)
-        {
-            stream.Seek(HeaderInfoLength, SeekOrigin.Begin);
-            int len = VectorIndexRows * VectorIndexCols * SegmentIndexSize;
-            var buff = new byte[len];
-            var rLen = stream.Read(buff, 0, buff.Length);
-            if (rLen != len) throw new IOException("incomplete read: read bytes should be " + len);
-            return buff;
-        }
-        public static byte[] LoadVectorIndexFromFile(string dbPath)
-        {
-            using (var fs = File.OpenRead(dbPath)) return LoadVectorIndex(fs);
-        }
-        public static byte[] LoadContent(Stream stream)
-        {
-            stream.Seek(0, SeekOrigin.Begin);
-            using (var ms = new MemoryStream())
-            {
-                stream.CopyTo(ms);
-                return ms.ToArray();
-            }
-        }
-
-        public static byte[] LoadContentFromFile(string dbPath)
-        {
-            using (var fs = File.OpenRead(dbPath)) return LoadContent(fs);
-        }
-
-        public static int GetInt2(byte[] b, int offset)
-        {
-            return (
-                (b[offset++] & 0x000000FF) |
-                (b[offset] & 0x0000FF00)
-            );
-        }
-        public static int GetInt(byte[] b, int offset)
-        {
-            return (
-                ((b[offset++]) & 0x000000FF) |
-                ((b[offset++] << 8) & 0x0000FF00) |
-                ((b[offset++] << 16) & 0x00FF0000) |
-                (int)((b[offset] << 24) & 0xFF000000)
-            );
-        }
-        public static long GetIntLong(byte[] b, int offset)
-        {
-            return (
-                ((b[offset++] & 0x000000FFL)) |
-                ((b[offset++] << 8) & 0x0000FF00L) |
-                ((b[offset++] << 16) & 0x00FF0000L) |
-                ((b[offset] << 24) & 0xFF000000L)
-            );
-        }
-
-        /* long int to ip string */
-        public static string Long2ip(long ip)
-        {
-            return string.Join(".", (ip >> 24) & 0xFF, (ip >> 16) & 0xFF, (ip >> 8) & 0xFF, (ip) & 0xFF);
-        }
-
-        public static byte[] shiftIndex = { 24, 16, 8, 0 };
-
-        /* check the specified ip address */
-        public static long checkIP(String ip)
-        {
-            String[]
-            ps = ip.Split('.');
-            if (ps.Length != 4) throw new Exception("invalid ip address `" + ip + "`");
-
-            long ipDst = 0;
-            for (int i = 0; i < ps.Length; i++)
-            {
-                int val = Convert.ToInt32(ps[i]);
-                if (val > 255)
-                {
-                    throw new Exception("ip part `" + ps[i] + "` should be less then 256");
-                }
-                ipDst |= ((long)val << shiftIndex[i]);
-            }
-
-            return ipDst & 0xFFFFFFFFL;
-        }
-    }
-}

binding/csharp/README.md

+# IP2Region.Net
+
+IP2Region c# xdb client
+
+## Installation
+
+Install the package with [NuGet](https://www.nuget.org/packages/IP2Region.Net)
+
+
+```bash
+Install-Package IP2Region.Net
+```
+
+## Usage
+
+```csharp
+using IP2Region.Net.XDB;
+
+//use default db and cache whole xdb file
+Searcher searcher = new Searcher();
+searcher.Search("ipaddress value");
+
+/*
+ * custom cache policy and xdb file path
+ * CachePolicy.Content default cache policy , cache whole xdb file , thread safe
+ * CachePolicy.VectorIndex cache vector index , reduce the number of IO operations , not thread safe!
+ * CachePolicy.File no cache , not thread safe!
+ */
+Searcher searcher = new Searcher(CachePolicy.File, "your xdb file path");
+
+```
+
+## ASP.NET Core Usage
+
+```csharp
+services.AddSingleton<ISearcher,Searcher>();
+```
+
+## Performance
+
+``` ini
+
+BenchmarkDotNet=v0.13.2, OS=Windows 11 (10.0.22000.856/21H2)
+AMD Ryzen 5 3550H with Radeon Vega Mobile Gfx, 1 CPU, 8 logical and 4 physical cores
+.NET SDK=6.0.400
+  [Host]     : .NET 6.0.8 (6.0.822.36306), X64 RyuJIT AVX2
+  DefaultJob : .NET 6.0.8 (6.0.822.36306), X64 RyuJIT AVX2
+
+
+```
+|                  Method |        Mean |     Error |    StdDev |
+|------------------------ |------------:|----------:|----------:|
+|     CachePolicy_Content |    224.6 ns |   4.44 ns |   7.41 ns |
+| CachePolicy_VectorIndex | 11,648.4 ns | 231.98 ns | 457.91 ns |
+
+
+
+## Contributing
+Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
+
+Please make sure to update tests as appropriate.
+
+## License
+[Apache License 2.0](https://github.com/lionsoul2014/ip2region/blob/master/LICENSE.md)
\ No newline at end of file