Optimization with protobuf files [ECR-3472]

[skletsun]

Overview

Protobuf specification files are taken now from a separate repository that is incorporated into the main project as a git submodule. git submodule init и git submodule update should be executed in order to fetch the content of the submodule.

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See: https://jira.bf.local/browse/ECR-3472

Definition of Done

• There are no TODOs left in the code
• Change is covered by automated tests
• The coding guidelines are followed
• Public API has Javadoc
• Method preconditions are checked and documented in the Javadoc of the method
• Changelog is updated if needed (in case of notable or breaking changes)
• The continuous integration build passes

[dmitry-timofeev]

The Java code changes can be extracted from f00c7f9. Checkstyle does not check auto-generated code, hence there is no need to exclude that package.

[dmitry-timofeev]

Do any instructions need to be updated?

[vitvakatu]

You also need to execute git submodule update before each build, don't you?

[skletsun]

No, the info about submodule revision is recorded under the main repo, so I believe that it makes sense executing this only after fetching updates for the main repo. And yes, it should also be stated somewhere.

[dmitry-timofeev]

fetching updates or switching to any new branch?

[skletsun]

When one creates a new branch within the current branch with submodules that are checked out, the new branch contains the same revision to submodules and the content of submodules folders remains the same.
When one gets switched to the branch that points to a different submodule revision then git submodule update is required I guess.
Well, the deeper we go here the more I feel like instruction turns into a guide to git for the user - wouldn't it be enough to just mention that protobuf files (or just some parts of the project) are a git submodule and user should pay attention to this?

[dmitry-timofeev]

Thanks, submodule mention shall be enough.

[MakarovS]

"git submodule init и git submodule update" unexpected Russian :D
Looks good to me, although I'd elaborate a little for why a user needs to retrieve submodules in CONTRIBUTING.md (to get protobuf files?)

[coveralls]

Coverage decreased (-0.1%) to 85.862% when pulling 4dd3461 on skletsun:proto-optimization-ecr-3472 into 655eb58 on exonum:dynamic-services.