读取部分不是并发的,而是处理。我用这种方式表达了标题,因为我最有可能使用该短语再次搜索此问题。 :)
我试图陷入僵局 超越例子 所以这对我来说是一次学习经历。我的目标是这些:
- 逐行读取文件(最终使用缓冲区来完成行组)。
- 将文本传递给
func()
做一些正则表达式的工作。 - 将结果发送到某处但避免使用互斥锁或共享变量。我正在向通道发送整数(总是数字1)。这有点愚蠢,但如果它没有引起问题,我想把它留下来,除非你们有一个更整洁的选择。
- 使用工作池来执行此操作。我不确定如何告诉工人们自己重新排队?
这里是 游乐场链接。我试着写有用的评论,希望这是有道理的。我的设计可能完全错误,所以不要犹豫重构。
package main
import (
"bufio"
"fmt"
"regexp"
"strings"
"sync"
)
func telephoneNumbersInFile(path string) int {
file := strings.NewReader(path)
var telephone = regexp.MustCompile(`\(\d+\)\s\d+-\d+`)
// do I need buffered channels here?
jobs := make(chan string)
results := make(chan int)
// I think we need a wait group, not sure.
wg := new(sync.WaitGroup)
// start up some workers that will block and wait?
for w := 1; w <= 3; w++ {
wg.Add(1)
go matchTelephoneNumbers(jobs, results, wg, telephone)
}
// go over a file line by line and queue up a ton of work
scanner := bufio.NewScanner(file)
for scanner.Scan() {
// Later I want to create a buffer of lines, not just line-by-line here ...
jobs <- scanner.Text()
}
close(jobs)
wg.Wait()
// Add up the results from the results channel.
// The rest of this isn't even working so ignore for now.
counts := 0
// for v := range results {
// counts += v
// }
return counts
}
func matchTelephoneNumbers(jobs <-chan string, results chan<- int, wg *sync.WaitGroup, telephone *regexp.Regexp) {
// Decreasing internal counter for wait-group as soon as goroutine finishes
defer wg.Done()
// eventually I want to have a []string channel to work on a chunk of lines not just one line of text
for j := range jobs {
if telephone.MatchString(j) {
results <- 1
}
}
}
func main() {
// An artificial input source. Normally this is a file passed on the command line.
const input = "Foo\n(555) 123-3456\nBar\nBaz"
numberOfTelephoneNumbers := telephoneNumbersInFile(input)
fmt.Println(numberOfTelephoneNumbers)
}