/protobuf-tutorial

Protocol Buffers - Usage and example code for CS457/557

Primary LanguageC++

Protocol Buffers - Usage and example code

This tutorial comes from Protocol Buffers Website

This directory contains example code that uses Protocol Buffers to manage an address book. Two programs are provided for each supported language. The add_person example adds a new person to an address book, prompting the user to input the person's information. The list_people example lists people already in the address book. The examples use the exact same format in all three languages, so you can, for example, use add_person_java to create an address book and then use list_people_python to read it.

These examples are part of the Protocol Buffers tutorial, located at: https://developers.google.com/protocol-buffers/docs/tutorials

Running protobuf on BU remote.cs machines

We'll be using Protocol Buffers 3.5.1 in this course. It is already installed in my home directory. This installation includes the protocol compiler (the protoc binary) and the protobuf runtime for the 3 languages that we use - C++, Java and Python. Let me know ASAP if you face any issues with running this on remote.

Note: Please read the Protocol Buffers tutorial on above link to get better idea.

Similar to Apache Thrift, you need to specify environment variables at compile and runtime.

  • Protobuf binary:
export PATH=/home/vchaska1/protobuf/bin:$PATH

The protocol compiler (protoc) binary is present at this location. It is required to generate code from .proto files.

  • Protobuf package configuration file:
export PKG_CONFIG_PATH=/home/vchaska1/protobuf/lib/pkgconfig

C++

First, add the C++ runtime libraries to LD_LIBRARY_PATH variable.

export LD_LIBRARY_PATH=/home/vchaska1/protobuf/lib

Then run "make cpp" in this directory to build the C++ example. It will create two executables: add_person_cpp and list_people_cpp. These programs simply take an address book file as their parameter. The add_person_cpp programs will create the file if it doesn't already exist.

To run the examples:

$ ./add_person_cpp addressbook.data
$ ./list_people_cpp addressbook.data

Python

Add the following two lines at the beginning of your Python code.

import sys
sys.path.append('/home/vchaska1/protobuf/protobuf-3.5.1/python')

(This should be already present in python files of this repo)

Make sure to add these lines before any protobuf related imports.

Then run "make python" to build two executables (shell scripts actually): add_person_python and list_people_python. They work the same way as the C++ executables.

To run the examples:

$ ./add_person_python addressbook.data
$ ./list_people_python addressbook.data

Java

Set the following CLASSPATH environment variable for runtime protobuf class discovery:

export CLASSPATH=/home/vchaska1/protobuf/protobuf-java-3.5.1.jar

Then run "make java". This will create the add_person_java/list_people_java executables (shell scripts) and can be used to create/display an address book data file.

To run the examples:

$ ./add_person_java addressbook.data
$ ./list_people_java addressbook.data

Observe that the C++, Python, and Java examples in this directory run in a similar way and can view/modify files created by other languages and vice versa.

Note: You can also install protobuf on your own machine and do the development work there. I personally found it easier. Please see the official website for instructions on this. HOWEVER, please make sure that your code compiles and works correctly on remote.cs machines before submitting.