Variable-length integers (varints)

As you are now aware, the payloads that are created by Protobuf are significantly smaller than the other popular data formats. One of the biggest factors of such small payloads is the use of variable-length integers (varints). Now, let’s not get ahead of ourselves. Before explaining how all of this works in Protobuf itself, let’s understand the idea of varints; then, we will see where they’re used in Protobuf.

As its name suggests, a varint is the concept of encoding integers into different byte sizes. What is not clear from the name is how it decides the length of the encoding. So, we are going to use an example to understand how that works.

First, we can see the result of encoding by using the skills we learned in previous chapters. We can write the following proto file (varint/encoding.proto):

syntax = "proto3";
message Encoding {
  int32 i32 = 1;
}

Then, we can define the data in a txtpb file...