From 5cfd5f824223c9c371a97f9d405839643f0e35c6 Mon Sep 17 00:00:00 2001
From: Argo Zhang <argo@live.ca>
Date: Fri, 21 Nov 2025 11:15:31 +0800
Subject: [PATCH] =?UTF-8?q?perf:=20=E5=A2=9E=E5=8A=A0=E5=90=91=E9=87=8F?=
 =?UTF-8?q?=E7=BC=93=E5=AD=98=E9=80=BB=E8=BE=91=E6=8F=90=E9=AB=98=E6=80=A7?=
 =?UTF-8?q?=E8=83=BD?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../Abstractions/AbstractCacheStrategy.cs      | 16 +++++++++++++---
 .../Internal/ContentCacheStrategy.cs           |  4 ++--
 .../Internal/VectorIndexCacheStrategy.cs       | 18 ++++++++----------
 binding/csharp/IP2Region.Net/XDB/Searcher.cs   |  7 +++++--
 4 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/binding/csharp/IP2Region.Net/Internal/Abstractions/AbstractCacheStrategy.cs b/binding/csharp/IP2Region.Net/Internal/Abstractions/AbstractCacheStrategy.cs
index 9ba96af..e277dde 100644
--- a/binding/csharp/IP2Region.Net/Internal/Abstractions/AbstractCacheStrategy.cs
+++ b/binding/csharp/IP2Region.Net/Internal/Abstractions/AbstractCacheStrategy.cs
@@ -10,11 +10,21 @@ namespace IP2Region.Net.Internal.Abstractions;
 
 internal abstract class AbstractCacheStrategy(string xdbPath)
 {
-    private const int BufferSize = 4096;
+    private const int BufferSize = 64 * 1024;
 
-    internal int IoCount { get; private set; }
+    public int IoCount { get; private set; }
 
-    internal virtual ReadOnlyMemory<byte> GetData(int offset, int length)
+    public void ResetIoCount()
+    {
+        IoCount = 0;
+    }
+
+    public virtual ReadOnlyMemory<byte> GetVectorIndexStartPos(int offset)
+    {
+        return GetData(256 + offset, 8);
+    }
+
+    public virtual ReadOnlyMemory<byte> GetData(int offset, int length)
     {
         byte[] buffer = ArrayPool<byte>.Shared.Rent(length);
         int totalBytesRead = 0;
diff --git a/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs b/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
index 0ef7251..94e7f51 100644
--- a/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
+++ b/binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs
@@ -10,9 +10,9 @@ namespace IP2Region.Net.Internal;
 
 class ContentCacheStrategy(string xdbPath) : AbstractCacheStrategy(xdbPath)
 {
-    ReadOnlyMemory<byte> _cacheData = ReadOnlyMemory<byte>.Empty;
+    ReadOnlyMemory<byte> _cacheData = default;
 
-    internal override ReadOnlyMemory<byte> GetData(int offset, int length)
+    public override ReadOnlyMemory<byte> GetData(int offset, int length)
     {
         if (_cacheData.IsEmpty)
         {
diff --git a/binding/csharp/IP2Region.Net/Internal/VectorIndexCacheStrategy.cs b/binding/csharp/IP2Region.Net/Internal/VectorIndexCacheStrategy.cs
index e9eb40a..4dea3fe 100644
--- a/binding/csharp/IP2Region.Net/Internal/VectorIndexCacheStrategy.cs
+++ b/binding/csharp/IP2Region.Net/Internal/VectorIndexCacheStrategy.cs
@@ -8,18 +8,16 @@ using IP2Region.Net.Internal.Abstractions;
 
 namespace IP2Region.Net.Internal;
 
-internal class VectorIndexCacheStrategy : AbstractCacheStrategy
+internal class VectorIndexCacheStrategy(string xdbPath) : AbstractCacheStrategy(xdbPath)
 {
-    const int HeaderInfoLength = 256;
-    const int VectorIndexRows = 256;
-    const int VectorIndexCols = 256;
-    const int VectorIndexSize = 8;
+    ReadOnlyMemory<byte> _vectorCahe = default;
 
-    readonly ReadOnlyMemory<byte> _vectorIndex;
-
-    public VectorIndexCacheStrategy(string xdbPath) : base(xdbPath)
+    public override ReadOnlyMemory<byte> GetVectorIndexStartPos(int offset)
     {
-        var vectorLength = VectorIndexRows * VectorIndexCols * VectorIndexSize;
-        _vectorIndex = base.GetData(HeaderInfoLength, vectorLength);
+        if (_vectorCahe.IsEmpty)
+        {
+            _vectorCahe = base.GetData(256, 256 * 256 * 8);
+        }
+        return _vectorCahe.Slice(offset, 8);
     }
 }
diff --git a/binding/csharp/IP2Region.Net/XDB/Searcher.cs b/binding/csharp/IP2Region.Net/XDB/Searcher.cs
index 5fcbf30..1aa7fc6 100644
--- a/binding/csharp/IP2Region.Net/XDB/Searcher.cs
+++ b/binding/csharp/IP2Region.Net/XDB/Searcher.cs
@@ -40,7 +40,7 @@ public class Searcher : ISearcher
     public string? Search(string ipStr)
     {
         var ipAddress = IPAddress.Parse(ipStr);
-        return Search(ipAddress);
+        return SearchCore(ipAddress.GetAddressBytes());
     }
 
     /// <summary>
@@ -63,6 +63,9 @@ public class Searcher : ISearcher
 
     string? SearchCore(byte[] ipBytes)
     {
+        // 重置 IO 计数器
+        _cacheStrategy.ResetIoCount();
+
         // 每个 vector 索引项的字节数
         var vectorIndexSize = 8;
 
@@ -74,7 +77,7 @@ public class Searcher : ISearcher
         var il1 = ipBytes[1];
         var idx = il0 * vectorIndexCols * vectorIndexSize + il1 * vectorIndexSize;
 
-        var data = _cacheStrategy.GetData(256 + idx, vectorIndexSize);
+        var data = _cacheStrategy.GetVectorIndexStartPos(idx);
         var sPtr = BinaryPrimitives.ReadUInt32LittleEndian(data.Span);
         var ePtr = BinaryPrimitives.ReadUInt32LittleEndian(data.Span.Slice(4));