goprotobuf VS mapstructure

Now let’s take a look at the source code of the protoc-gen-go plugin:

Wait, you say, in Go you can embed a struct with default method implementations to "inherit" them in your composed struct... sure, except any methods called by those methods are early-bound in the original struct, completely ignoring your wrapper, so the best you can do is "not implemented" rather than actually implement something. It is at least a way to prevent semver-major breakage, which the gRPC generator uses, but that's about as far as it gets you.

The classic answer is protobufs. You can serialize out to binary format.

Seems like go is pretty middle of the road. I can only guess as to why but it probably has to do with heavy usage of pointers and reflection which are much slower than other implementations. Gogo/protobuf (RIP) solved this performance with code generation, but the the official go protobuf implementation has essentially eschewed it. I do wonder how the benchmark would look using the new vitess proto library for Go (which has many of the benefits of gogo but with active development and an API built on top of the Google one)

Maybe I'm missing something, but my read of [golang/protobuf#364](https://github.com/golang/protobuf/issues/364) was that the re-organization in protobuf-go v2 was allow for optimizations like gogoprotobuf to be developed without requiring a complete fork. I totally understand that the authors of gogoprotobuf do not have the time to re-architect their library to use these hooks, but best I can figure this generator does not use these hooks either. Instead it defines additional member functions, and wrappers that look for those specialized functions and fallback to the generic ones if not found.

I am thinking about stuff like the [ProtoMethods](https://pkg.go.dev/google.golang.org/[email protected]/reflec...) API.

I wonder why not? Did the authors of the vtprotobuf extension not want to bite off that much work? Is the new API not sufficient to do what they want (thus failing some of the goals expressed in golang/protobuf#364?

In this case try approach with line by line generation. Very much like what protoc-gen-go does for Go code: https://github.com/golang/protobuf/blob/ae97035608a719c7a1c1c41bed0ae0744bdb0c6f/protoc-gen-go/grpc/grpc.go#L142, need to implement this kind of generator yourself.

Something like this: https://github.com/golang/protobuf/blob/master/internal/gengogrpc/grpc.go

Maybe https://github.com/mitchellh/mapstructure can do what you want? It has some options for Remainder Values and Omit Empty

I've tried using mapstructure to then marshal the map fields into a struct which mostly works (it struggles with times and custom time types which requires a workaround for each case), but this doesn't feel very idiomatic and requires two passes at marshaling.

Although some orders may have more records maybe a superset can be indentified that you can actually create a struct of it and after gathereing first all values into a map then convert it to a struct maybe using a library like https://github.com/mitchellh/mapstructure . this way you can at least isolate the non structured data only on the data extraction part and the rest of your application can work with well formed structs.

Alternatively, you could try https://github.com/mitchellh/mapstructure if you don't know what your incoming structure is

I'm doing it by validating a map[string]any first then putting it into a structure using mapstructure. It covers most use-cases and offers the most flexibility, at the expense of a bit of performance.

That said, it is possible to do this with JSON using something like https://github.com/tidwall/gjson or if you are fine with the switch statement but don't want to marshal and unmarshal again: https://github.com/mitchellh/mapstructure

https://github.com/mitchellh/mapstructure because we have JSON documents which contain rugged arrays ;-)

I've been using mapstructure.Decode to great effect, but currently can't figure out why a given mapping doesn't work. I'd appreciate it if someone could point out wtf I'm doing wrong or at least in the right direction:

What do you mean by "decode"? I've used https://github.com/mitchellh/mapstructure but that doesn't quite look like what you're doing.