> We can define protobuf's version by using syntax = "proto2" or syntax > = "proto3" in proto files with proto3 compiler. I think this is what > Stack mentioned as compatibility mode.
I mean, "We can define protobuf's 'specification' 'version at compilation time by using syntax = "proto2""... - Tsuyoshi On Wed, Mar 29, 2017 at 9:13 AM, Tsuyoshi Ozawa <oz...@apache.org> wrote: >> Stack mentioned a compatibility mode that uses the proto2 semantics. > > We can define protobuf's version by using syntax = "proto2" or syntax > = "proto3" in proto files with proto3 compiler. I think this is what > Stack mentioned as compatibility mode. > > https://github.com/golang/protobuf/blob/master/proto/proto3_proto/proto3.proto#L32 > >> Did some more googling, found this: >> >> https://groups.google.com/d/msg/protobuf/Z6pNo81FiEQ/fHkdcNtdAwAJ >> >> Feng Xiao appears to be a Google engineer, and suggests workarounds like >> packing the fields into a byte type. No mention of a PB2 compatibility mode. >> Also here: >> >> https://groups.google.com/d/msg/protobuf/bO2L6-_t91Q/-zIaJAR9AAAJ >> >> Participants say that unknown fields were dropped for automatic JSON >> encoding, since you can't losslessly convert to JSON without knowing the >> type. > > Feng mentions in the thread: >> The following are the main new features in language version 3: > > Does it mean that, if the syntax = "proto3", there are no > compatibility mode because of the changes of how to handle enum or > missing fields between proto3 "specification" and proto2 > "specification"? On the other hand, if files are compiled with the > syntax = "proto2", I think we could treat the generated files as with > protobuf 2.x "runtime". > > Best > - Tsuyoshi --------------------------------------------------------------------- To unsubscribe, e-mail: common-dev-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-dev-h...@hadoop.apache.org
