C# list vs byte array efficiency over network

Question

Okay so I'm trying to make a multiplayer game using a self built netcode in unity3d using c#,

The thing is since I'm using raw tcp I need to convert everything to a byte[] but I got sick of using Array.Copy. Since I'm reserving a few bytes of every message sent over a network as sort of a message identifier that I can use to interpret the data I receive.

So my question is, for the purpose of making this code more friendly to myself, is it a terrible idea to use a list of bytes instead of a byte array and once I've prepared the message to be sent I can just call .ToArray on that list?

Would this be terrible for performance?

Marc_Gravell_23354 · Answer

As a general rule when dealing with sockets: you should usually be working with oversized arrays (ArrayPool<byte>.Shared can be useful here), and then use the Send overloads that accepts either the byte[], int, int (offset+count), or ArraySegment<byte> - so you aren't constantly re-copying things, and can re-use buffers. However, frankly: you may also way to look into "pipelines"; this is the new IO API that Kestrel uses that deals with all the buffer management for you, so you don't have to. In the core framework, pipelines is currently mostly server-focused, but this is being improved hopefully in .NET 5 as part of "Bedrock" - however, client-side pipelines wrappers are available in Pipelines.Sockets.Unofficial (on NuGet).

To be explicit: no, constantly calling ToArray() on a List<byte> is not a good way of making buffers more convenient; that will probably work, but could contribute to GC stalls, plus it is unnecessary overhead in your socket code.

To be explicit: no, constantly calling ToArray() on a List is not a good way of making buffers more convenient; that will probably work, but could contribute to GC stalls, plus it is unnecessary overhead in your socket code.

C# list vs byte array efficiency over network

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