riegeli VS Protobuf

> didn’t find any standard for separating protobuf messages

The fact that protobufs are not self-delimiting is an endless source of frustration, but I know of 2 standards:

- SerializeDelimited* is part of the protobuf library: https://github.com/protocolbuffers/protobuf/blob/main/src/go...

- Riegeli is "a file format for storing a sequence of string records, typically serialized protocol buffers. It supports dense compression, fast decoding, seeking, detection and optional skipping of data corruption, filtering of proto message fields for even faster decoding, and parallel encoding": https://github.com/google/riegeli

Note: If you want to use the Google Protobuf compiler for code generation, download it from GitHub based on your OS. Follow this link for code generation instructions.

Unary length prefix is a solid technique. I would be careful with the performance claims, though. Sometimes what the machine can do is surprising and the performance of a system that looks like it needs to loop and branch is faster than you expected. The protobuf project, unsurprisingly for a project of its age, has several different varint parsing strategies. One is described at https://github.com/protocolbuffers/protobuf/blob/main/src/go... and another at https://github.com/protocolbuffers/protobuf/blob/main/src/go...

See protobuf field presence:

https://github.com/protocolbuffers/protobuf/blob/main/docs/f...

This is a language-agnostic serialization library that is much faster than JSON and provides way more compact representation. There are several implementations with different features and trade offs. μpb is a very lightweight C++ implemantion that uses arena allocations.

I have raised an issue requesting the addition of optional scalar types, but it is not planned to be supported by protoc-gen-kotlin.

protobuf: go get -u google.golang.org/protobuf/proto

It's because they changed the versioning format: https://github.com/protocolbuffers/protobuf/releases?page=5

But I suppose old version still receive bugfixes.

For at least 4 years protobuf has had decent support for self-describing messages (very similar to avro) as well as reflection

https://github.com/protocolbuffers/protobuf/blob/main/src/go...

Xgooglers trying to make do on the cheap will just create a Union of all their messages and include the message def in a self-describing message pattern. Super-sensitive network I/O can elide the message def (empty buffer) and any for RecordIO clone well file compression takes care of the definition.

Definitely useful to be able to dig out old defs but protobuf maintainers have surprisingly added useful features so you don’t have to.

Bonus points tho for extracting the protobuf defs that e.g. Apple bakes into their binaries.