Proper way to use FastBufferWriter, can't find much in doc.

Unity Engine
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1

I’m trying to figure out what is the best way to use FastBufferWriter for network message, especially for network refresh that can happen each network tick. Ideally I would he able to reuse the same buffer multiple times.

I know there is Allocator.Temp and Allocator.Persitant, but nothing is explained about how they each work internally.

  1. If i declare a class member as FastBufferWriter Persistent does that mean i can reuse it each refresh?

  2. Do i need to call Dispose on it before rewriting or would that clear the memory? If not then how do i reset the writer for writing without reallocating memory (I would always send the same data size).

  3. Then if I use persistent does that mean I need to manually Dispose it when the class holding the FastBufferWriter get deleted or it will memory leak? Is OnDestroy the best place to do that?

  4. If I use a Temp allocator does that mean i never need to call Dispose? And when does it get cleared?

  5. Finally is there a fast way to copy a FastBufferReader into a FastBufferWriter, i see no function to create a new writer based on a reader that would be so useful for forwarding msg received by server to another client.

1 Like
2

I would also be interested in answers to these questions.

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So I figured out 4 and 5. But I’m still not using Persistant as I have no idea how it works. Would like an answer to my questions 1-3.

#4 For Temp, you DO need to call Dispose after the msg is sent.

#5 This is how i forward a msg (convert Reader to Writer)

public void Forward(string type, ulong target, FastBufferReader reader, NetworkDelivery delivery)
{
        reader.Seek(0); //Reset reader
        reader.ReadValueSafe(out ulong header); //Ignore header
        byte[] bytes = new byte[reader.Length - reader.Position];
        reader.ReadBytesSafe(ref bytes, reader.Length - reader.Position);
        FastBufferWriter writer = new FastBufferWriter(bytes.Length, Allocator.Temp);
        writer.WriteBytesSafe(bytes, bytes.Length);
        network.NetworkManager.CustomMessagingManager.SendNamedMessage(type, target, writer, delivery);
        writer.Dispose();
}

A built-in function to do this would probably be ideal though so you don’t need so much allocation to do it.

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4

Thanks for sharing! Small note: You could use a using statement so that the writer is automatically disposed when the method is exited.

    public void Forward(string type, ulong target, FastBufferReader reader, NetworkDelivery delivery)
    {
        reader.Seek(0); //Reset reader
        reader.ReadValueSafe(out ulong header); //Ignore header
        byte[] bytes = new byte[reader.Length - reader.Position];
        reader.ReadBytesSafe(ref bytes, reader.Length - reader.Position);
        using FastBufferWriter writer = new FastBufferWriter(bytes.Length, Allocator.Temp);
        writer.WriteBytesSafe(bytes, bytes.Length);
        network.NetworkManager.CustomMessagingManager.SendNamedMessage(type, target, writer, delivery);
    }