Protocol Buffer Examples

Lei Mao

Introduction

Protocol Buffer, also known as Protobuf, is Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. Protocol Buffers Version 3 (Proto3) was released in 2016. However, the official tutorials on the Google protobuf website are still for Proto2. The official samples are using Proto3 and CMake, however, its CMake is not standard and many of its macros were not documented on the official CMake website.

In this repository, I re-implemented Google's official Protobuf C++ and Python example using Proto3 and CMake with the best practice. I also put code comments as many as possible to make sure the code is human readable and easy to understand.

Dependencies

• Google Protocol Buffers 3.21.9
• CMake 3.14.4+

Files

.
├── CMakeLists.txt
├── docker
│   └── protobuf.Dockerfile
├── examples
│   ├── add_people
│   │   ├── add_people.cc
│   │   └── CMakeLists.txt
│   ├── CMakeLists.txt
│   └── list_people
│       ├── CMakeLists.txt
│       └── list_people.cc
├── LICENSE.md
├── protos
│   ├── addressbook.proto
│   └── CMakeLists.txt
└── README.md

Usages

Build Docker Image

$ docker build -f docker/protobuf.Dockerfile --build-arg PROTOBUF_VERSION=21.9 --build-arg NUM_JOBS=8 --tag protobuf-cmake:21.9 .

Run Docker Container

$ docker run -it --rm -v $(pwd):/mnt protobuf-cmake:21.9

Build Examples

$ cmake -B build
$ cmake --build build --config Release --parallel

All the executable files would be generated in build/bin directory.

Run Examples

The C++ and Python serialization and deserialization can be used interchangeably (C++ serialization + C++ deserialization, C++ serialization + Python deserialization, Python serialization + Python deserialization, Python serialization + C++ deserialization), as the data formats are all generated from the same proto file and they are all the same.

Add People Using C++

$ ./build/bin/add_people build/data.pb # Add people to data
build/data.pb: File not found.  Creating a new file.
Add person to address book? yes | no
yes
Enter person ID number: 
12345
Enter name: 
Lei Mao
Enter email address (blank for none): 
[email protected]
Enter a phone number (or leave blank to finish): 
+1123456789
Is this a mobile, home, or work phone? mobile | home | work 
home
Enter a phone number (or leave blank to finish): 

Add person to address book? yes | no
yes
Enter person ID number: 
54321
Enter name: 
Andrew Ng
Enter email address (blank for none): 
[email protected]
Enter a phone number (or leave blank to finish): 

Add person to address book? yes | no
no

List People Using C++

$ python examples-python/add_people.py build/data.pb # Read data
Person ID: 12345
  Name: Lei Mao
  E-mail address: [email protected]
  Home phone #: +1123456789
  Updated: 2019-06-06T19:07:39Z
Person ID: 54321
  Name: Andrew Ng
  E-mail address: [email protected]
  Updated: 2019-06-06T19:08:20Z

Add People Using Python

$ python examples-python/list_people.py build/data.pb 
build/data.pb: File not found.  Creating a new file.
Add person to address book? yes | no
yes
Enter person ID number: 12345
Enter name: Lei Mao
Enter email address (blank for none): [email protected]
Enter a phone number (or leave blank to finish): +1123456789
Is this a mobile, home, or work phone? home
Enter a phone number (or leave blank to finish): 
Add person to address book? yes | no
yes
Enter person ID number: 54321
Enter name: Andrew Ng
Enter email address (blank for none): [email protected]
Enter a phone number (or leave blank to finish): 
Add person to address book? yes | no
no

List People Using Python

$ python examples-python/list_people.py build/data.pb 
Person ID: 12345
  Name: Lei Mao
  E-mail address: [email protected]
  Home phone #: +1123456789
Person ID: 54321
  Name: Andrew Ng
  E-mail address: [email protected]