Update Readers/Writers for Buffers & Fixes bugs (#283)

- [X] Renames PacketReader to CircularBufferReader
- [X] Fixes bugs with CircularBufferReader
- [X] Adds CircularBufferWriter
- [X] Adds SpanWriter
- [X] Adds SpanReader

Bumps release version

Projects/Server/Utilities/Utility.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using System.Net;
 using System.Net.Sockets;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Xml;
 using Server.Random;
@@ -106,6 +107,55 @@ namespace Server
         public static Encoding Unicode => m_Unicode ??= new UnicodeEncoding(true, false, false);
         public static Encoding UnicodeLE => m_UnicodeLE ??= new UnicodeEncoding(false, false, false);
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetByteLengthForEncoding(Encoding encoding) =>
+            encoding.BodyName switch
+            {
+                "utf-16BE" => 2,
+                "utf-16"   => 2,
+                "utf-32BE" => 4,
+                "utf-32"   => 4,
+                _          => 1
+            };
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int IndexOfTerminator(ReadOnlySpan<byte> buffer, int sizeT) =>
+            sizeT switch
+            {
+                2 => MemoryMarshal.Cast<byte, char>(buffer).IndexOf((char)0) * 2,
+                4 => MemoryMarshal.Cast<byte, uint>(buffer).IndexOf((uint)0) * 4,
+                _ => buffer.IndexOf((byte)0)
+            };
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static bool IsSafeChar(ushort c) => c >= 0x20 && c < 0xFFFE;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static string GetString(ReadOnlySpan<byte> span, Encoding encoding, bool safeString = false)
+        {
+            string s = encoding.GetString(span);
+
+            if (!safeString)
+            {
+                return s;
+            }
+
+            ReadOnlySpan<char> chars = s.AsSpan();
+
+            StringBuilder stringBuilder = null;
+
+            for (int i = 0, last = 0; i < chars.Length; i++)
+            {
+                if (!IsSafeChar(chars[i]) || stringBuilder != null && i == chars.Length - 1)
+                {
+                    (stringBuilder ??= new StringBuilder()).Append(chars.Slice(last, i - last));
+                    last = i + 1; // Skip the unsafe char
+                }
+            }
+
+            return stringBuilder?.ToString() ?? s;
+        }
+
         public static void Separate(StringBuilder sb, string value, string separator)
         {
             if (sb.Length > 0)