Protocol buffers

Protocol buffers are Google’s language-neutral, platform-neutral, extensible mechansim for serializing structured data. It’s faster and simpler. It has support for C++, C#, DART, GO, JAVA, PYTHON.

• With protocol buffers, you write a .proto description of the data structure you want to store.

• From that, protocol buffer compiler creates a class that implements automatic encoding and parsing of the protocol buffer data with efficient binary format.

• The generated class provides getters and setters for the fields that make up a protocol buffer and takes care of the details of reading and writing the protocol buffer as a unit.

• Importantly, the protocol buffer format supports the idea of extending the format over time in such a way that the code can still read data encoded with the old format.

Let’s work with a simple example.

• touch example.proto. Create an empty example.proto file.

• Open with editor example.proto, add the following code, save and close it. Detailed explanation follows.

syntax = "proto2"
package example;

message ImageFile{

  required string filename = 1;
  required string filepath = 2;
  optional string absoltuepath = 3;

  message Size{

    required int height = 1;
    required int width = 2;

  }

}