dispatcher.go

package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	d := &dispatcher{
		in:  make(chan int),
		out: make(chan int),
	}
	d.run(3)
	d.run(2)

	go func() {
		for i := range d.output() {
			fmt.Println(i)
		}
	}()

	go func() {
		for i := 0; i < 30; i++ {
			d.input() <- i
		}
		d.stop()
	}()

	d.wait()

}

type dispatcher struct {
	wg  sync.WaitGroup
	in  chan int
	out chan int
}

func (d *dispatcher) work() {
	d.wg.Add(1)
	defer d.wg.Done()

	for i := range d.in {
		// ここにロジックを書く(ここでは100倍するだけ)
		time.Sleep(time.Second)
		d.out <- i * 100
	}
}

func (d *dispatcher) input() chan<- int {
	return d.in
}

func (d *dispatcher) output() <-chan int {
	return d.out
}

func (d *dispatcher) run(n int) {
	for i := 0; i < n; i++ {
		go d.work()
	}
}

func (d *dispatcher) stop() {
	close(d.in)
}

func (d *dispatcher) wait() {
	d.wg.Wait()
	close(d.out)
}