哈希字符串的有界并行性[重复]

Question

This question already has an answer here:

• How would you define a pool of goroutines to be executed at once in Golang? 3 answers

Trying to solve the problem of reading phone numbers from a file (line by line) and hash them concurrently (md5) in go with a maximum of 100 concurrent process maximum, creating a fixed number of goroutines. tried using go pipeline and bounded parallelism but did not work. any guidance, please?

this is what I tried, https://play.golang.org/p/vp7s512l8w4

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Answer 1

package main

import (
    "bufio"
    "fmt"
    "os"
    "sync"
)

func hashPhoneNumers(phoneNO string, ch chan struct{}, group *sync.WaitGroup) {
    do_hash(phoneNO)
    <-ch
    group.Done()
}

func do_hash(s string) {
    fmt.Println("do hash: ", s)
}

func main() {
    c := make(chan struct{}, 100)
    file, err := os.Open("file.txt")
    if err != nil {
        fmt.Println(err)
        os.Exit(-1)
    }
    defer file.Close()
    line := bufio.NewScanner(file)

    wg := sync.WaitGroup{}
    for line.Scan() {
        // with a maximum of 100 concurrent process maximum
        c <- struct{}{}
        wg.Add(1)
        go hashPhoneNumers(line.Text(), c, &wg)
    }

    // wait all goroutines done
    wg.Wait()
    close(c)
}

this works fine