Book Image

Protocol Buffers Handbook

By : Clément Jean
Book Image

Protocol Buffers Handbook

By: Clément Jean

Overview of this book

Explore how Protocol Buffers (Protobuf) serialize structured data and provides a language-neutral, platform-neutral, and extensible solution. With this guide to mastering Protobuf, you'll build your skills to effectively serialize, transmit, and manage data across diverse platforms and languages. This book will help you enter the world of Protocol Buffers by unraveling the intricate nuances of Protobuf syntax and showing you how to define complex data structures. As you progress, you’ll learn schema evolution, ensuring seamless compatibility as your projects evolve. The book also covers advanced topics such as custom options and plugins, allowing you to tailor validation processes to your specific requirements. You’ll understand how to automate project builds using cutting-edge tools such as Buf and Bazel, streamlining your development workflow. With hands-on projects in Go and Python programming, you’ll learn how to practically apply Protobuf concepts. Later chapters will show you how to integrate data interchange capabilities across different programming languages, enabling efficient collaboration and system interoperability. By the end of this book, you’ll have a solid understanding of Protobuf internals, enabling you to discern when and how to use and redefine your approach to data serialization.
Table of Contents (13 chapters)

What are custom options?

Protobuf custom options are a way to annotate part of the schema with contextual information. Think of them as normal Protobuf options but with custom names. It is as simple as that. The reason they exist is also simple – it is extensibility. If you do not find the right option for your use case, just create one by yourself.

Now, let us face it, the first time we hear about Protobuf custom options, it is hard to understand why, except for the pretty abstract extensibility concept, we would need them. As such, I want to show you some examples of custom options and how they are used.

The first project that is very popular and uses Protobuf custom options is protovalidate (https://github.com/bufbuild/protovalidate/). If you have never heard of it, it is a “series of libraries designed to validate Protobuf messages at runtime based on user-defined validation rules”.

Let us see an example. Let us say that we want the name of the user...