Serialization and deserialization
Serialization and deserialization are two concepts that are used in many ways and in many kinds of applications. This section is going to discuss these two concepts in the context of Protobuf. So, even if you feel confident about your understanding of these two notions, it is important to get your head straight and understand them properly. Once you do, it will be easier to deal with the Encoding details section where we are going to delve deeper into how Protobuf serializes and deserializes data under the hood.
Let us start with serialization and then let us touch upon deserialization, which is just the opposite process. The goal of serialization is to store data, generally in a more compact or readable representation, to use it later. For Protobuf, this serialization happens on the data that you set in your generated code’s objects. For example, if we set the Id, Username, and Right fields in our Account struct, this data will be what Protobuf will work on. It will turn each field into a binary representation with different algorithms depending on the field type. And after that, we use this in-memory binary to either send data over the network (with gRPC, for example) or store it in more persistent storage.
Once it is time for us to use this serialized data again, Protobuf will perform deserialization. This is the process of reading the binary created earlier and populating the data back into an object in your favorite programming language to be able to act on it. Once again, Protobuf will use different algorithms depending on the type of data to read the underlying binary and know how to set or not set each of the fields of the object in question.
To summarize, Protobuf performs binary serialization to make data more compact than other formats such as XML or JSON. To do so, it will read data from the different fields of the generated code’s object, turn it into binary with different algorithms, and then when we finally need the data, Protobuf will read the data and populate the fields of a given object.