fix: Removes custom BitArray (#1597)

### Summary

The BitArray class will be optimized over the next several years for various platforms/hardware and maintaining a duplicate for serialization is not practical. Removing the custom implementation. Recommend against using BitArray for serialization unless it is absolutely necessary.

Projects/Server.Tests/Tests/Collections/BitArrayTests.cs

@@ -1,29 +0,0 @@
-using Server.Collections;
-using Xunit;
-
-namespace Server.Tests;
-
-public class BitArrayTests
-{
-    [Fact]
-    public void TestBitArray()
-    {
-        var bitArray = new BitArray(700); // Restricted Spells;
-        bitArray.Set(5, true);
-        bitArray.Set(39, true);
-        bitArray.Set(125, true);
-
-        // Simulate World Saving
-        var writer = new BufferWriter(1024, false);
-        writer.Write(bitArray); // Save it to a file
-
-        // Simulate World Loading
-        var reader = new BufferReader(writer.Buffer);
-        var bitArrayTest = reader.ReadBitArray();
-        Assert.Equal(700, bitArrayTest.Length);
-        for (var i = 0; i < bitArrayTest.Length; i++)
-        {
-            Assert.Equal(i is 5 or 39 or 125, bitArrayTest.Get(i));
-        }
-    }
-}

Projects/Server/Json/Converters/BitArrayEnumIndexConverter.cs

@@ -14,9 +14,9 @@
  *************************************************************************/
 
 using System;
+using System.Collections;
 using System.Text.Json;
 using System.Text.Json.Serialization;
-using Server.Collections;
 
 namespace Server.Json;
 

Projects/Server/Serialization/BinaryFileReader.cs

@@ -19,7 +19,6 @@ using System.IO;
 using System.Runtime.CompilerServices;
 using System.Text;
 using Server.Buffers;
-using Server.Collections;
 using Server.Logging;
 using Server.Text;
 
@@ -166,15 +165,6 @@ public class BinaryFileReader : IGenericReader, IDisposable
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public int Read(Span<byte> buffer) => _reader.Read(buffer);
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public BitArray ReadBitArray()
-    {
-        var length = ((IGenericReader)this).ReadEncodedInt();
-
-        // BinaryReader doesn't expose a Span slice of the buffer, so we use a custom ctor
-        return new BitArray(_reader, length);
-    }
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public long Seek(long offset, SeekOrigin origin) => _reader.BaseStream.Seek(offset, origin);
 

Projects/Server/Serialization/BufferReader.cs

@@ -15,6 +15,7 @@
 
 using System;
 using System.Buffers.Binary;
+using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
@@ -221,21 +222,6 @@ public class BufferReader : IGenericReader
         return length;
     }
 
-    public BitArray ReadBitArray()
-    {
-        var bitLength = ((IGenericReader)this).ReadEncodedInt();
-        var length = BitArray.GetByteArrayLengthFromBitLength(bitLength);
-
-        if (length > _buffer.Length - _position)
-        {
-            throw new OutOfMemoryException();
-        }
-
-        var bitArray = new BitArray(_buffer.AsSpan(_position, length), bitLength);
-        _position += length;
-        return bitArray;
-    }
-
     public virtual long Seek(long offset, SeekOrigin origin)
     {
         Debug.Assert(

Projects/Server/Serialization/BufferWriter.cs

@@ -20,7 +20,6 @@ using System.Diagnostics;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Text;
-using Server.Collections;
 using Server.Text;
 
 namespace Server;
@@ -135,17 +134,6 @@ public class BufferWriter : IGenericWriter
         Index += length;
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void Write(BitArray bitArray)
-    {
-        var byteLength = BitArray.GetByteArrayLengthFromBitLength(bitArray.Length);
-
-        ((IGenericWriter)this).WriteEncodedInt(bitArray.Length);
-        FlushIfNeeded(byteLength);
-        bitArray.CopyTo(_buffer.AsSpan((int)Index, byteLength));
-        Index += byteLength;
-    }
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public virtual long Seek(long offset, SeekOrigin origin)
     {

Projects/Server/Serialization/IGenericReader.cs

@@ -14,6 +14,8 @@
  *************************************************************************/
 
 using System;
+using System.Buffers;
+using System.Collections;
 using System.IO;
 using System.Net;
 using Server.Collections;
@@ -120,7 +122,17 @@ public interface IGenericReader
         return new Guid(bytes);
     }
 
-    BitArray ReadBitArray();
+    public BitArray ReadBitArray()
+    {
+        var byteArrayLength = ReadEncodedInt();
+
+        // We need an exact array size since the ctor doesn't allow for offset/length, not much we can do at this point.
+        var byteArray = new byte[byteArrayLength];
+
+        Read(byteArray);
+
+        return new BitArray(byteArray);
+    }
 
     TextDefinition ReadTextDefinition()
     {

Projects/Server/Serialization/IGenericWriter.cs

@@ -14,9 +14,13 @@
  *************************************************************************/
 
 using System;
+using System.Buffers;
+using System.Collections;
+using System.Collections.Specialized;
 using System.IO;
 using System.Net;
-using Server.Collections;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Server;
 
@@ -162,7 +166,17 @@ public interface IGenericWriter
         Write(stack);
     }
 
-    void Write(BitArray bitArray);
+    public void Write(BitArray bitArray)
+    {
+        var bytesLength = (bitArray.Length - 1 + (1 << 3)) >>> 3;
+        var arrayBuffer = ArrayPool<byte>.Shared.Rent(bytesLength);
+
+        WriteEncodedInt(bytesLength);
+        bitArray.CopyTo(arrayBuffer, 0);
+
+        Write(arrayBuffer.AsSpan(0, bytesLength));
+        ArrayPool<byte>.Shared.Return(arrayBuffer);
+    }
 
     void Write(TextDefinition def)
     {

Projects/UOContent/Skills/AntiMacroSystem.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.IO;
 using System.Runtime.InteropServices;