major upgrade multi and single file support

Author: MPCoreDeveloper

SingleFileTest.cs

@@ -0,0 +1,42 @@
+using SharpCoreDB.Storage.Scdb;
+using System.Runtime.InteropServices;
+
+class SingleFileTest
+{
+    static void Main(string[] args)
+    {
+        Console.WriteLine("Testing SCDB Structures");
+
+        // Test ScdbFileHeader
+        var header = ScdbFileHeader.CreateDefault(4096);
+        Console.WriteLine($"Header magic: 0x{header.Magic:X16}");
+        Console.WriteLine($"Header version: {header.FormatVersion}");
+        Console.WriteLine($"Page size: {header.PageSize}");
+        Console.WriteLine($"Header valid: {header.IsValid}");
+
+        // Test serialization
+        Span<byte> buffer = stackalloc byte[(int)ScdbFileHeader.HEADER_SIZE];
+        header.WriteTo(buffer);
+
+        var parsed = ScdbFileHeader.Parse(buffer);
+        Console.WriteLine($"Parsed magic: 0x{parsed.Magic:X16}");
+        Console.WriteLine($"Round-trip success: {header.Magic == parsed.Magic}");
+
+        // Test BlockEntry
+        var entry = new BlockEntry
+        {
+            BlockType = (uint)BlockType.TableData,
+            Offset = 4096,
+            Length = 1024,
+            Flags = (uint)BlockFlags.Dirty
+        };
+
+        var namedEntry = BlockEntry.WithName("table:users:data", entry);
+        var name = namedEntry.GetName();
+        Console.WriteLine($"Block name: {name}");
+        Console.WriteLine($"Block type: {namedEntry.BlockType}");
+        Console.WriteLine($"Block offset: {namedEntry.Offset}");
+
+        Console.WriteLine("\n✅ SCDB structures test completed successfully!");
+    }
+}

SingleFileTest.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="SingleFileTest.cs" />
+    <Compile Include="src\SharpCoreDB\Storage\Scdb\ScdbStructures.cs" />
+  </ItemGroup>
+
+</Project>

docs/SCDB_COMPILATION_FIXES.md

@@ -12,6 +12,7 @@ namespace SharpCoreDB;
 
 using Microsoft.Extensions.DependencyInjection;
 using SharpCoreDB.Core.Cache;
+using SharpCoreDB.Storage;
 using System.Collections.Concurrent;
 using System.Security.Cryptography;
 using System.Text.Json;