Golang Coursera

signer.go

package main

import (
	"fmt"
	"sort"
	"strconv"
	"strings"
	"sync"
)

// сюда писать код

var mu sync.Mutex

var SingleHash job = func(in, out chan interface{}) {
	wg := sync.WaitGroup{}
	for i := range in {
		wg.Add(1)
		go func(i interface{}) {
			str := fmt.Sprintf("%v", i)
			crc := make(chan string)
			md := make(chan string)
			crcMd := make(chan string)

			go func() {
				crc <- DataSignerCrc32(str)
				close(crc)
			}()

			go func() {
				mu.Lock()
				md <- DataSignerMd5(str)
				close(md)
				mu.Unlock()
			}()

			go func() {
				crcMd <- DataSignerCrc32(<-md)
				close(crcMd)
			}()

			hash := <-crc + "~" + <-crcMd

			out <- hash
			wg.Done()
		}(i)
	}
	wg.Wait()
}

var MultiHash job = func(in, out chan interface{}) {
	wgOuter := sync.WaitGroup{}
	for i := range in {
		wgOuter.Add(1)
		go func(i interface{}){
			hash := ""
			str := fmt.Sprintf("%v", i)
			parts := make([]string, 6, 6)
			wgInner := sync.WaitGroup{}
			for j := 0; j <= 5; j++ {
				wgInner.Add(1)
				go func(index int) {
					parts[index] = DataSignerCrc32(strconv.Itoa(index) + str)
					wgInner.Done()
				}(j)
			}
			wgInner.Wait()
			hash += strings.Join(parts, "")
			out <- hash
			wgOuter.Done()
		}(i)
	}
	wgOuter.Wait()
}

var CombineResults job = func(in, out chan interface{}) {
	var collector []string
	for i := range in {
		collector = append(collector, i.(string))
	}
	sort.Strings(collector)
	out <- strings.Join(collector, "_")
}

func ExecutePipeline(jobs ...job) {
	out := make(chan interface{})
	lastOut := out
	if len(jobs) > 1 {
		lastOut = out
		for i := 1; i < len(jobs); i++ {
			lastOut = next(lastOut, jobs[i])
		}
	}
	jobs[0](nil, out)
	close(out)
	<-lastOut
}

func next(originIn chan interface{}, currentJob job) chan interface{} {
	in := make(chan interface{})
	out := make(chan interface{})
	go func() {
		currentJob(in, out)
		close(out)
	}()
	go func() {
		for i := range originIn {
			in <- i
		}
		close(in)
	}()
	return out
}