CodedOutputStream :GC is generated when encoding

[sunrui19941128]

public byte[] Encode(int id,IMessage msg)
{
using (MemoryStream rawOutput = new MemoryStream())
{
using (CodedOutputStream output = new CodedOutputStream(rawOutput))
{
output.WriteEnum(id);
output.WriteMessage(msg);
output.Flush();
return rawOutput.ToArray();
}
}
}

In Unity, every time this code is encoded, a considerable amount of GC will be generated, which is about 5k per call, or more than 200 k per frame

[ObsidianMinor]

You can cut down on most of the GC overhead by calculating the size of the array ahead of time and writing directly to it like so:

public byte[] Encode(int id, IMessage msg)
{
    var len = CodedOutputStream.ComputeEnumSize(id) + CodedOutputStream.ComputeMessageSize(msg);
    var arr = new byte[len];
    using (CodedOutputStream output = new CodedOutputStream(arr))
    {
        output.WriteEnum(id);
        output.WriteMessage(msg);
    }
    return arr;
}

[sunrui19941128]

Thanks,And that's what I've done since then. I've done dynamic computation of size and then I've optimized a lot of memory by opening up a little bit.

[jtattermusch]

In addition to what @ObsidianMinor has said, we are also planning a new serialization/deserialization API that can avoid allocations completely (at least in some cases).
The WIP is here (but it's probably going to take a bit until it lands as the change is not trivial) #5888