What if we made the API a bit more general. TSReturnCode TSTxnClientProtocolStackGet(TSHttpTxn txnp, int count, char **result, int* actual); This function returns an array of static character strings that represent the protocol stack for the user agent connection. *result* is an array of char const* pointers with at least *count* elements. The protocols are listed from higher to lower in *result*. If there is insufficient space in *result* the lower protocols are not stored. The number of protocols is return in *actual* if *actual* is not NULL. Note that *actual* can be larger than *count* - this indicates that protocols were discarded and not put in to *result*. Pointers in *result* that are not required are unchanged. No element of *result* past the first *count* elements will be modified.
Callers can detect the size of the return array by std::min(*actual*,*count*). Alternatively the array can be pre-zero'd and the caller can walk until a NULL pointer is found. If this is required then *count* can be set to be one less than the actual array size. Callers interested in just the top level protocol can pass *count* as 1 with the address of a char const* and NULL for *actual*. Defined strings: Protocol Tag HTTP/2 h2HTTP/1.1 http/1.1HTTP/1.0 http/1.0QUIC quicTCP tcpUDP udpTLS tlsWeb Sockets ws
