Instruction for Generating Go Protocol Buffers

The module (github.com/golang/protobuf) contains Go bindings for Protocol Buffers.

The documentation and tutorials by Google can be found at Protocol Buffers Go tutorials

Package index

Summary of the packages provided by this module:

• proto: Package proto provides functions operating on Protocol Buffers messages such as cloning, merging, and checking equality, as well as binary serialization and text serialization.

• protoc-gen-go/plugin: Package plugin is the generated package for google/protobuf/compiler/plugin.proto.

• protoc-gen-go: The protoc-gen-go binary is a protoc plugin to generate a Go Protocol Buffers package.

How do we use Protocol Buffers?

• Protocol Buffers is faster than JSON and has 3 main components that we have to deal with:

  • Message Descriptors

    • When using Protocol Buffers we have to define our own messages structure in .proto files.

  • Message Implementations

    • Messages definitions are not enough to represent and exchange data in any programming language. We have to generate classes/objects to deal with data in the chosen programming language.
    • To install the compiler, download packages:
      • go get -u google.golang.org/protobuf
      • go get -u google.golang.org/protobuf/proto
    • To install the Go protocol buffers plugin:
      • go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
    • To compile:
      • protoc --go_out=. ./protocol/*.proto

  • Parsing and Serialization

    • After defining and creating Protocol Buffers messages, we need to be able to exchange these messages.

Example Client-Server TCP Connection

Package index

• flag: Package flag implements command-line flag parsing: -admin client and -admin server

• io/ioutil: Package ioutil implements some I/O utility functions.

• net: Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. Although the package provides access to low-level networking primitives, most clients will need only the basic interface provided by the Dial, Listen, and Accept functions and the associated Conn and Listener interfaces. The crypto/tls package uses the same interfaces and similar Dial and Listen functions.

Logic Explanation

• Send protocol message CML: go run ./main.go -admin client

• Listen to protocol message CML: go run ./main.go -admin server

• Server listens on tcp, 127.0.0.1:8085

• sendData() uses net.Dial("tcp", "127.0.0.1:8085") to create a TCP connection between the server and the client. Function receives data []byte parameter and writes it to the connection it created before

• runClient() creates a protocol object and uses proto.Marshal(&object) to marshal the protocol object before sending it to the connection by calling sendData().

• runServer uses net.Listen("tcp", "127.0.0.1:8085") to listen on TCP. Function waits for reading data from the connection by using ioutil.ReadAll(connection) and then unmarshal the data received by proto.Unmarshal(data, object)

• Demo

  

Contributor

• Minh Tran (Me)