FastBufferWriter,Reader have not Endian issue?

Unity Engine
, ,
1

I think this code will cause an ‘little-endian vs big-endian’ issue between platforms.

Is the platform using big-endian gone?

        internal unsafe void WriteUnmanaged<T>(in T value) where T : unmanaged
        {
            fixed (T* ptr = &value)
            {
                byte* bytes = (byte*)ptr;
                WriteBytes(bytes, sizeof(T));
            }
        }
        public unsafe void WriteBytes(byte* value, int size, int offset = 0)
        {
#if DEVELOPMENT_BUILD || UNITY_EDITOR
            if (Handle->InBitwiseContext)
            {
                throw new InvalidOperationException(
                    "Cannot use BufferWriter in bytewise mode while in a bitwise context.");
            }
            if (Handle->Position + size > Handle->AllowedWriteMark)
            {
                throw new OverflowException($"Attempted to write without first calling {nameof(TryBeginWrite)}()");
            }
#endif
            UnsafeUtility.MemCpy((Handle->BufferPointer + Handle->Position), value + offset, size);
            Handle->Position += size;
        }
2

Endianness can certainly be different between devices. You may have spotted a potential issue here. Please report it on the Netcode github repository:

Slim chance that perhaps UnsafeUtility.MemCpy takes care of this internally. Or the endianess correction can also be done on the receiving end. Check the corresponding “ReadBytes” methods.

3

I don’t think that MemCpy is converting endian.

There is no processing in reading either.

        public unsafe void ReadBytes(byte* value, int size, int offset = 0)
        {
#if DEVELOPMENT_BUILD || UNITY_EDITOR
            if (Handle->InBitwiseContext)
            {
                throw new InvalidOperationException(
                    "Cannot use BufferReader in bytewise mode while in a bitwise context.");
            }
            if (Handle->Position + size > Handle->AllowedReadMark)
            {
                throw new OverflowException($"Attempted to read without first calling {nameof(TryBeginRead)}()");
            }
#endif
            UnsafeUtility.MemCpy(value + offset, (Handle->BufferPointer + Handle->Position), size);
            Handle->Position += size;
        }
4
5

THANK YOU !!