During the BF-28130 performance investigation, we noticed that the execution of initializeAPIParameters() spends a lot of time maintaining a red-black tree that implements the std::set used by APIParametersFromClient::parseProtected() to check whether the BSON document has any duplicate fields. The parser is generated from IDL, so this happens in every similar parser.

The goal of this ticket is to do preliminary performance testing to check whether replacing the std::set with std::unordered_set in these parsers would yield any performance improvements.