mhewedy/order_emited_elements_using_chan.go

## order_emited_elements_using_chan.go
package main

import (
	"fmt"
	"github.com/fatih/color"
	"sync"
)

func main() {

	var wg sync.WaitGroup
	wg.Add(11)

	const numElements = 20

	ch := make(chan int)
	orderCh := make(chan int, numElements)

	for i := 0; i < 10; i++ {
		go func(i int) {
			for v := range ch {
				fmt.Println(color.RedString("unordered element:%v", v))
				orderCh <- v
			}
			wg.Done()
		}(i)
	}

	for i := 0; i < numElements; i++ {
		ch <- i
	}
	close(ch)

	var values = make([]int, 0, numElements)

	for v := range orderCh {
		latest := -1
		if len(values) > 0 {
			latest = values[len(values)-1]
		}
		if v == latest+1 {
			values = append(values, v)
			fmt.Println(color.GreenString("ordered element:%v", v))
		} else {
			orderCh <- v // resend to the channel
			fmt.Println("value", color.YellowString("%v", v), "resent")
		}

		if len(values) == cap(values) {
			close(orderCh)
		}
	}

	wg.Done()
	wg.Wait()
}
	package main

	import (
	"fmt"
	"github.com/fatih/color"
	"sync"
	)

	func main() {

	var wg sync.WaitGroup
	wg.Add(11)

	const numElements = 20

	ch := make(chan int)
	orderCh := make(chan int, numElements)

	for i := 0; i < 10; i++ {
	go func(i int) {
	for v := range ch {
	fmt.Println(color.RedString("unordered element:%v", v))
	orderCh <- v
	}
	wg.Done()
	}(i)
	}

	for i := 0; i < numElements; i++ {
	ch <- i
	}
	close(ch)

	var values = make([]int, 0, numElements)

	for v := range orderCh {
	latest := -1
	if len(values) > 0 {
	latest = values[len(values)-1]
	}
	if v == latest+1 {
	values = append(values, v)
	fmt.Println(color.GreenString("ordered element:%v", v))
	} else {
	orderCh <- v // resend to the channel
	fmt.Println("value", color.YellowString("%v", v), "resent")
	}

	if len(values) == cap(values) {
	close(orderCh)
	}
	}

	wg.Done()
	wg.Wait()
	}