refactor: 使用接口代替虚类

binding/csharp/IP2Region.Net/Internal/Abstractions/AbstractCacheStrategy.cs

@@ -1,54 +0,0 @@
-// Copyright 2025 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 <lzh.shap@gmail.com>
-// @Date   2023/07/25
-// Updated by Argo Zhang <argo@live.ca> at 2025/11/21
-
-using System.Buffers;
-
-namespace IP2Region.Net.Internal.Abstractions;
-
-internal abstract class AbstractCacheStrategy(string xdbPath)
-{
-    protected const int HeaderInfoLength = 256;
-    protected const int VectorIndexSize = 8;
-
-    private const int BufferSize = 64 * 1024;
-
-    public int IoCount { get; private set; }
-
-    protected FileStream XdbFileStream = new(xdbPath, FileMode.Open, FileAccess.Read, FileShare.Read, BufferSize, FileOptions.RandomAccess);
-
-    public void ResetIoCount()
-    {
-        IoCount = 0;
-    }
-
-    public virtual ReadOnlyMemory<byte> GetVectorIndex(int offset) => GetData(HeaderInfoLength + offset, VectorIndexSize);
-
-    public virtual ReadOnlyMemory<byte> GetData(long offset, int length)
-    {
-        byte[] buffer = ArrayPool<byte>.Shared.Rent(length);
-        int totalBytesRead = 0;
-        try
-        {
-            XdbFileStream.Seek(offset, SeekOrigin.Begin);
-
-            int bytesRead;
-            while (totalBytesRead < length)
-            {
-                bytesRead = XdbFileStream.Read(buffer, totalBytesRead, length);
-                totalBytesRead += bytesRead;
-
-                IoCount++;
-            }
-        }
-        finally
-        {
-            ArrayPool<byte>.Shared.Return(buffer);
-        }
-
-        return new ReadOnlyMemory<byte>(buffer, 0, totalBytesRead);
-    }
-}

binding/csharp/IP2Region.Net/Internal/CacheStrategyFactory.cs

@@ -5,14 +5,13 @@
 // @Date   2023/07/25
 // Updated by Argo Zhang <argo@live.ca> at 2025/11/21
 
-using IP2Region.Net.Internal.Abstractions;
 using IP2Region.Net.XDB;
 
 namespace IP2Region.Net.Internal;
 
-class CacheStrategyFactory(string xdbPath)
+static class CacheStrategyFactory
 {
-    public AbstractCacheStrategy CreateCacheStrategy(CachePolicy cachePolicy) => cachePolicy switch
+    public static ICacheStrategy CreateCacheStrategy(CachePolicy cachePolicy, string xdbPath) => cachePolicy switch
     {
         CachePolicy.Content => new ContentCacheStrategy(xdbPath),
         CachePolicy.VectorIndex => new VectorIndexCacheStrategy(xdbPath),

binding/csharp/IP2Region.Net/Internal/ContentCacheStrategy.cs

@@ -5,20 +5,16 @@
 // @Date   2023/07/25
 // Updated by Argo Zhang <argo@live.ca> at 2025/11/21
 
-using IP2Region.Net.Internal.Abstractions;
-
 namespace IP2Region.Net.Internal;
 
-class ContentCacheStrategy : AbstractCacheStrategy
+class ContentCacheStrategy : FileCacheStrategy
 {
     private readonly ReadOnlyMemory<byte> _cacheData;
 
     public ContentCacheStrategy(string xdbPath) : base(xdbPath)
     {
         _cacheData = base.GetData(0, (int)XdbFileStream.Length);
-        XdbFileStream.Close();
-        XdbFileStream.Dispose();
     }
 
-    public override ReadOnlyMemory<byte> GetData(long offset = 0, int length = 0) => _cacheData.Slice((int)offset, length);
+    public override ReadOnlyMemory<byte> GetData(long offset, int length) => _cacheData.Slice((int)offset, length);
 }

binding/csharp/IP2Region.Net/Internal/FileCacheStrategy.cs

@@ -5,11 +5,59 @@
 // @Date   2023/07/25
 // Updated by Argo Zhang <argo@live.ca> at 2025/11/21
 
-using IP2Region.Net.Internal.Abstractions;
+using System.Buffers;
 
 namespace IP2Region.Net.Internal;
 
-class FileCacheStrategy(string xdbPath) : AbstractCacheStrategy(xdbPath)
+class FileCacheStrategy(string xdbPath) : ICacheStrategy
 {
+    protected const int HeaderInfoLength = 256;
+    protected const int VectorIndexSize = 8;
 
+    protected const int BufferSize = 64 * 1024;
+
+    protected FileStream XdbFileStream = new(xdbPath, FileMode.Open, FileAccess.Read, FileShare.Read, BufferSize, FileOptions.RandomAccess);
+
+    public int IoCount { get; set; }
+
+    public void ResetIoCount()
+    {
+        IoCount = 0;
+    }
+
+    public virtual ReadOnlyMemory<byte> GetVectorIndex(int offset) => GetData(HeaderInfoLength + offset, VectorIndexSize);
+
+    public virtual ReadOnlyMemory<byte> GetData(long offset, int length)
+    {
+        var buffer = ArrayPool<byte>.Shared.Rent(length);
+        try
+        {
+            int totalBytesRead = 0;
+            XdbFileStream.Seek(offset, SeekOrigin.Begin);
+
+            int bytesRead;
+            while (totalBytesRead < length)
+            {
+                bytesRead = XdbFileStream.Read(buffer, totalBytesRead, length - totalBytesRead);
+                if (bytesRead == 0)
+                {
+                    break;
+                }
+
+                totalBytesRead += bytesRead;
+                IoCount++;
+            }
+
+            var ret = new byte[totalBytesRead];
+            if (totalBytesRead > 0)
+            {
+                Array.Copy(buffer, 0, ret, 0, totalBytesRead);
+            }
+            return ret;
+        }
+        finally
+        {
+            ArrayPool<byte>.Shared.Return(buffer);
+        }
+    }
 }

binding/csharp/IP2Region.Net/Internal/ICacheStrategy.cs

@@ -0,0 +1,19 @@
+// Copyright 2025 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 <lzh.shap@gmail.com>
+// @Date   2023/07/25
+// Updated by Argo Zhang <argo@live.ca> at 2025/11/21
+
+namespace IP2Region.Net.Internal;
+
+internal interface ICacheStrategy
+{
+    int IoCount { get; }
+
+    void ResetIoCount();
+
+    ReadOnlyMemory<byte> GetVectorIndex(int offset);
+
+    ReadOnlyMemory<byte> GetData(long offset, int length);
+}

binding/csharp/IP2Region.Net/Internal/VectorIndexCacheStrategy.cs

@@ -5,11 +5,9 @@
 // @Date   2023/07/25
 // Updated by Argo Zhang <argo@live.ca> at 2025/11/21
 
-using IP2Region.Net.Internal.Abstractions;
-
 namespace IP2Region.Net.Internal;
 
-class VectorIndexCacheStrategy : AbstractCacheStrategy
+class VectorIndexCacheStrategy : FileCacheStrategy
 {
     private const int VectorIndexRows = 256;
     private const int VectorIndexCols = 256;
@@ -18,10 +16,7 @@ class VectorIndexCacheStrategy : AbstractCacheStrategy
 
     public VectorIndexCacheStrategy(string xdbPath) : base(xdbPath)
     {
-        XdbFileStream.Seek(HeaderInfoLength, SeekOrigin.Begin);
+        _vectorCache = GetData(HeaderInfoLength, VectorIndexRows * VectorIndexCols * VectorIndexSize);
-        var buffer = new byte[VectorIndexRows * VectorIndexCols * VectorIndexSize];
-        var length = XdbFileStream.Read(buffer, 0, buffer.Length);
-        _vectorCache = new ReadOnlyMemory<byte>(buffer);
     }
 
     public override ReadOnlyMemory<byte> GetVectorIndex(int offset) => _vectorCache.Slice(offset, VectorIndexSize);

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

@@ -7,7 +7,6 @@
 
 using IP2Region.Net.Abstractions;
 using IP2Region.Net.Internal;
-using IP2Region.Net.Internal.Abstractions;
 using System.Buffers.Binary;
 using System.Diagnostics.CodeAnalysis;
 using System.Net;
@@ -18,24 +17,18 @@ namespace IP2Region.Net.XDB;
 /// <summary>
 /// <see cref="ISearcher"/> 实现类
 /// </summary>
-public class Searcher : ISearcher
+/// <remarks>
+/// <inheritdoc/>
+/// </remarks>
+public class Searcher(CachePolicy cachePolicy, string xdbPath) : ISearcher
 {
-    private readonly AbstractCacheStrategy _cacheStrategy;
+    private readonly ICacheStrategy _cacheStrategy = CacheStrategyFactory.CreateCacheStrategy(cachePolicy, xdbPath);
 
     /// <summary>
     /// <inheritdoc/>
     /// </summary>
     public int IoCount => _cacheStrategy.IoCount;
 
-    /// <summary>
-    /// <inheritdoc/>
-    /// </summary>
-    public Searcher(CachePolicy cachePolicy, string dbPath)
-    {
-        var factory = new CacheStrategyFactory(dbPath);
-        _cacheStrategy = factory.CreateCacheStrategy(cachePolicy);
-    }
-
     /// <summary>
     /// <inheritdoc/>
     /// </summary>
@@ -93,7 +86,7 @@ public class Searcher : ISearcher
         {
             int m = (int)(l + h) >> 1;
 
-            var p = (int)sPtr + m * indexSize;
+            var p = sPtr + m * indexSize;
             var buff = _cacheStrategy.GetData(p, indexSize);
 
             var s = buff.Span.Slice(0, length);
@@ -114,7 +107,7 @@ public class Searcher : ISearcher
             }
         }
 
-        var regionBuff = _cacheStrategy.GetData((int)dataPtr, dataLen);
+        var regionBuff = _cacheStrategy.GetData(dataPtr, dataLen);
         return Encoding.UTF8.GetString(regionBuff.Span.ToArray());
     }