main.go

package main

import (
	"fmt"
	"math/rand"
	"time"
)

type image int

type imageQueue chan image

func bigImageGenerator() imageQueue {
	queue := make(imageQueue)

	go func() {
		for i := 0; i < 1000; i++ {
			img := rand.Intn(100)
			fmt.Println("new big image:", img)
			queue <- image(img)
		}

		close(queue)
	}()

	return queue
}

func compressImage(bigImages imageQueue, compressed imageQueue) {
	for {
		select {
		case image := <-bigImages:
			fmt.Println("compressing big image:", image)

			image = image / 10

			time.Sleep(time.Second * 2 * time.Duration(rand.Intn(10)))

			compressed <- image
		}
	}
}

func main() {
	bigImages := bigImageGenerator()

	compressedImages := make(imageQueue)

	for range make([]int, 10) {
		go compressImage(bigImages, compressedImages)
	}

	for compressedImage := range compressedImages {
		fmt.Println("Compressed:", compressedImage)
	}
}