[wesm]

To be clear for anyone reading, we're parsing and generating the data-related protobufs ourselves, and retaining ownership of the memory returned by gRPC to obtain zero copy.

The C++ details are found in

https://github.com/apache/arrow/blob/master/cpp/src/arrow/fl...

[jumpingmice]

Have you considered/tried using the new ParseContext instead of CodedInputStream? It is performance-oriented.

Edit: Apparently it's also the default in protobuf 3.10

[wesm]

I wasn't aware of it but will take a look. Thanks!