You can think of ByteString as an immutable byte array. That’s pretty much it. It’s a byte[] which you can use in a protobuf. Protobuf does not let you use Java arrays because they’re mutable. ByteString exists because String is not suitable for representing arbitrary sequences of bytes. String is specifically for character data. The … Read more
Turns out there is a way to find out if a default value is actually missing or not (thanks to some friends at google for this answer): message Record { uint32 fileno = 1; uint64 pos = 2; uint64 bmsPos = 3; oneof scanMode_present { uint32 scanMode = 4; } uint32 version = 5; // … Read more
The EnumDescriptor and EnumValueDescriptor classes can be used for this kind of manipulation, and the the generated .pb.h and .pb.cc names are easy enough to read, so you can look through them to get details on the functions they offer. In this particular case, the following should work (untested): std::string requestTypeString = MyMessage_RequestType_Name(requestType);
If you use ASN.1 with Unaligned PER, and define your data types using the appropriate constraints (e.g., specifying lower/upper bounds for integers, upper bounds for the length of lists, etc.), your encodings will be very compact. There will be no bits wasted for things like alignment or padding between the fields, and each field will … Read more
All you need is: repeated string users = 9; You don’t need the optional modifier, and it looks like it is confusing the parser. A repeated field is inherently optional: you just don’t add any values. As for com.google.protobuf.ProtocolStringList: check that the version of the .proto compiler (protoc) you are using is an exact match … Read more
The command line you are showing does not enable the grpc plugin. You need to specify an _out argument for the grpc plugin, which enables the plugin and specifies where it should output files. Since the plugin is likely not in your PATH, you also need to tell protoc how to find the plugin with … Read more
You can certainly send even a binary payload with an HTTP request, or in an HTTP response. Just write the bytes of the protocol buffer directly into the request/response, and make sure to set the content type to “application/octet-stream”. The client, and server, should be able to take care of the rest easily. I don’t … Read more
EDIT: The freeze_graph.py script, which is part of the TensorFlow repository, now serves as a tool that generates a protocol buffer representing a “frozen” trained model, from an existing TensorFlow GraphDef and a saved checkpoint. It uses the same steps as described below, but it much easier to use. Currently the process isn’t very well … Read more
The “lite” version is not able to serialize to or from iostream, or “FileDescriptor“, and it cannot use the Reflection feature (although it does use refection), and… a scattering of other features. My advice is to just use the lite version until you come across a feature that requires the full version. It is very … Read more
Protocol Buffers is a very mature framework, having been first introduced nearly 15 years ago at Google. It’s certainly not dead: Nearly every service inside Google uses it. But after so much usage, there probably isn’t much that needs to change at this point. In fact, they did a major release (3.0) this year, but … Read more