buildingBlockchain

Building Blockchain with Go 👣

Tutorial

Start a module

Development

rest.go

1. url 정의
2. router 만들기 (handler)
3. controller 만들기

Concepts

In Go, nil is the zero value for pointers, interfaces, maps, slices, channels and function types, representing an uninitialized value. 함수명을 대문자로 시작하면 외부에서 호출 가능

• Golang functions vs methods
• Member variable : 대소문자 구분
• Once : 스레드, 고루틴과 상관 없이 오지 1번만 실행
• Singleton Pattern : 단 하나의 instance만을 공유
• text/template
• Marshal : interface를 받아 JSON으로 변환
• Struct field tags
• Stringer
• MarshalText
• Gorilla Web Toolkit
  • Gorilla WebSocket
• bolt db
  • bolt browser
  • bolt web
  • bbolt
• gob : value를 byte로 encode or decode
• iota : iota를 활용한 프로그래밍
• godoc

  godoc -http=:6060

Channels

// Only Send Channel
func send(c chan<- int) {
	for i := range [10]int{} {
		fmt.Printf(">> sending %d <<\n", i)
		c <- i
		fmt.Printf(">> sent %d <<\n", i)
	}
	close(c) // avoid deadlock
}

// Only Receive Channel
func receive(c <-chan int) {
	for {
		time.Sleep(10 * time.Second)
		a, ok := <-c
		if !ok {
			fmt.Println("Done")
			break
		}
		fmt.Printf("|| received %d ||\n", a)
	}
}

func main() {
	c := make(chan int, 10) // Buffer Channel
	go send(c)
	receive(c)
}

Testing

go test ./... -v

Coverage

# create profile
go test -v -coverprofile cover.out ./...

# visualize
go tool cover -html=cover.out

Tools

• MVP.CSS