proto2 | orbit-db visualization | Data Visualization library

From the docs:

If you are using sbt-protoc and importing protos like scalapb/scalapb.proto, or common protocol buffers like google/protobuf/wrappers.proto:

Add the following to your build.sbt:

libraryDependencies += "com.thesamet.scalapb" %% "scalapb-runtime" % scalapb.compiler.Version.scalapbVersion % "protobuf"

This tells sbt-protoc to extract protos from this jar (and all its dependencies, which includes Google's common protos), and make them available in the include path that is passed to protoc.

It is important to add that by setting preserve_unknown_fields to false you are turning off a protobuf feature that could prevent data loss when different parts of a distributed system are not running the same version of the schema.

Because it's not useful to have a Self as a parameter type of a method. Suppose that you can do:

No Google reference is needed here; you have extended FieldOptions, which is the descriptor metadata type that relates to fields. protobuf-net has an implementation of that in the protobuf-net.Reflection package, in exactly where this could be expected: Google.Protobuf.Reflection.FieldOptions.

However! I doubt that this is going to do what you expect. In this scenario, you have defined a "custom option". Custom options aren't related to runtime instance data - they are part of the .proto DSL, and are usually used to influence code generation; in your case, it would be something like:

The csharp_out parameter is a folder, not a file, and that isn't how you use proto_path (again, a folder); and it is =, not : - in your case you probably want:

OK, I worked this out...

In the case where you have a short-lived connection, the socket closing would signify the end of the payload, so no extra logic is required.

In my case, I have a long-lived connection, so closing the socket to signify the end of the payload wouldn't work.

With a Java Client & Server, you could get around this by using:

MessageLite.writeDelimitedTo(OutputStream)

then on the recipient side:

MessageLite.parseDelimitedFrom(InputStream).

Easy enough...

But in the Python API, there is no writeDelimitedTo() function. So instead we must recreate what writeDelimitedTo() is doing. Fortunately, it's simple. It simply adds a _VarintBytes equal to the payload size to the beginning of the message!

That's a bug in protobuf-net; I've fixed in in this commit, which not yet available in nuget - but note that this will apply in v3 only (I haven't back-ported the fix to the v2 branch).

No, you can't link .pb.* files generated with protoc 2.0 against libprotobuf 3.0. Just like with any shared library, an increment in the major version number means a breaking API change.

Compatibility with proto2 means that Proto 2 syntax is supported (syntax = "proto2"). Also proto3 is binary-compatible with proto2 on the wire.

I don't want to update legacy protos to proto3 as it might require major refactoring in the legacy code.

Chances are, if you re-generate your .pb files with protoc 3 and recompile, it'll work without refactoring (the default syntax is still proto2).

generator/proto/nanopb_pb2.py", line 10, in from google.protobuf import symbol_database as _symbol_database ImportError: cannot import name 'symbol_database'

It seems there may be a version conflict between protoc version and your python-protobuf version. Try to remove nanopb_pb2.py, it should get autogenerated again possibly with better luck.

Considering you are using the binary package, you can also call generator_bin/nanopb_generator, which should have all the dependencies already included.

Protobuf

It's not allowed, neither by proto2 specs (as in your example code) nor by proto3 specs.

As shown in the specs (either of above mentioned), a package declaration follows the pattern:

package = "package" fullIdent ";"

i.e. the keyword package followed by a fullIdent followed by one ; semicolon, where fullIdent is defined as:

fullIdent = ident { "." ident }

i.e. at least one ident followed by zero or more other ident's preceded by ., where ident is defined as:

ident = letter { letter | decimalDigit | "_" }

i.e. at least one letter, followed by zero or more letters ([A-Z], [a-z]), digits ([0-9]), or the underscore _ character.

So in conclusion, you can't have a minus (dash) - character in your protobuf package name.

Go

Additionally, as @colm.anseo pointed out, Go package names also don't allow dash - characters either:

PackageName = identifier . where identifier = letter { letter | unicode_digit } .

(The underscore character is considered a letter.)