protobuf

README

protobuf example

Using protobuf to show data -> marshal -> snd -> rcv -> unmarshal -> data.

These are my 6 main example of using protobuf,

• protobuf <- You are here
• protobuf-NATS-publish-subscribe
• protobuf-NATS-queue-groups
• protobuf-NATS-queue-groups-request-reply (I like this one)
• protobuf-NATS-request-reply
• protobuf-NATS-request-reply-goroutines

Table of contents,

• STEP 1 - DEFINE .proto FILE
• STEP 2 - COMPILE .proto FILE
• STEP 3 - IMPLEMENT (RUN)
• THE FLOW
• HIGH-LEVEL ILLUSTRATION

Documentation and reference,

• Refer to my protobuf cheat sheet for information on installation and use.

GitHub Webpage

STEP 1 - DEFINE .proto FILE

Define a protocol buffer file messages.proto that declares the messages that are going to be serialized. A message is just an aggregate containing a set of typed fields.

Structure for this example is,

message Person {
    string name = 1;
    int32 age = 2;
    string email = 3;
    string phone = 4;
    uint32 count = 5;
}

STEP 2 - COMPILE .proto FILE

Compile the protocol buffer file to get the wrappers and place this file in the same directory as protobuf.go.

cd protoc
protoc --go_out=. messages.proto
cp messages.pb.go ..

Results in messages.pb.go that implements all messages as go structs and types.

STEP 3 - IMPLEMENT (RUN)

Run the code,

go run protobuf.go messages.pb.go

THE FLOW

The flow to send data over a pipe is,

• DATA
• MARSHALL
• SEND
• RECEIVE
• UNMARSHAL
• DATA

Usually, you have two separate processes but I kept everything inside one process to keep it simple.

DATA

Now lets create the message to send. Create a pointer to a type Person struct.

sndPerson := &Person{
    Name:  "Jeff",
    Age:   20,
    Email: "blah@blah.com",
    Phone: "555-555-5555",
    Count: 1,
}

MARSHAL

sndMsg, err := proto.Marshal(sndPerson)

SEND

Now lets pretend we're sending the message sndMsg over a pipe.

pipe := sndMsg

RECEIVE

rcvMsg := pipe

UNMARSHAL -> DATA

Now lets create an empty pointer to the same struct from our protobuf file and unmarshal it.

rcvPerson := &Person{}
err = proto.Unmarshal(rcvMsg, rcvPerson)

HIGH-LEVEL ILLUSTRATION

This illustration may help show what we did,