SIMD optimizations

src/McProtoNet/McProtoNet.Serialization/Extensions.cs

@@ -0,0 +1,111 @@
+using System.Buffers.Binary;
+using System.Runtime.InteropServices;
+
+namespace McProtoNet.Serialization;
+
+public static class ReadArraysSIMDExtensions
+{
+    public static int[] ReadArrayInt32BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(int) * length);
+        ReadOnlySpan<int> ints = MemoryMarshal.Cast<byte, int>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            int[] result = new int[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+    public static long[] ReadArrayInt64BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(long) * length);
+        ReadOnlySpan<long> ints = MemoryMarshal.Cast<byte, long>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            long[] result = new long[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+    public static short[] ReadArrayInt16BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(short) * length);
+        ReadOnlySpan<short> ints = MemoryMarshal.Cast<byte, short>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            short[] result = new short[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+    public static ushort[] ReadArrayUnsignedInt16BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(ushort) * length);
+        ReadOnlySpan<ushort> ints = MemoryMarshal.Cast<byte, ushort>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            ushort[] result = new ushort[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+    public static uint[] ReadArrayUnsignedInt32BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(uint) * length);
+        ReadOnlySpan<uint> ints = MemoryMarshal.Cast<byte, uint>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            uint[] result = new uint[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+    public static ulong[] ReadArrayUnsignedInt64BigEndian(this MinecraftPrimitiveReaderSlim reader, int length) 
+    {
+        if (reader.RemainingCount < length)
+        {
+            throw new InsufficientMemoryException();
+        }
+
+        ReadOnlySpan<byte> bytes = reader.Read(sizeof(ulong) * length);
+        ReadOnlySpan<ulong> ints = MemoryMarshal.Cast<byte, ulong>(bytes);
+        if (BitConverter.IsLittleEndian)
+        {
+            ulong[] result = new ulong[length];
+            BinaryPrimitives.ReverseEndianness(ints, result);
+            return result;
+        }
+        return ints.ToArray();
+    }
+
+}