ENH: AMF3 over-the-wire optimization

[EmosewaMC]

Is your feature request related to a problem?

Currently, the AMF3 serialization always writes the strings by value. This can be costly with an over the wire transfer with lots of data.

Describe the solution you'd like

An optimization would be, like the Deserializer, a serializer class which keeps track of what strings have been written and utilizes the reference part of the format. The following is a method of accomplishing this which will work:

class Writer {
  map<string, int> referenceTracker;
  void Serialize(string str, RakNet::BitStream* stream) {
    if (str.empty()) {
      stream->Write29bitInt(1); // empty strings are never passed by referenece
      return;
    }
    auto itr = referenceTracker.find(str);
    if (itr != referenceTracker.end()) {
      stream->Write29bitInt((itr->second << 1UL)); // shift left 1 and mark lowest bit with 0 to denote this is a reference to the previous string of number x.
      return;
    }
    auto size = referenceTracker.size(); // size pre-insert is the reference number
    referenceTracker[str] = size; // assign the number to this string value
    stream->Write29bitint((str.size() << 1) | 1); // bit 1 is the flag bit for a string size
    stream->Write(str.c_str(), str.size()); // write the string to the stream 
  }
}

the above code is simply an example and not representative of what a final product should look like and is mostly to get the idea across.

Repository breaking implications

Could break UI msgs

Describe alternatives you've considered

becoming one with AMF

Additional context

No response