go_channel_test

package main

import (
    "fmt"
    ff "gochanneltest/utils"
    "os"
    "strings"
    "sync"
    "time"
)

var (
    wg      sync.WaitGroup
    crGuard sync.RWMutex
)

func getInfo(folder string, c chan<- string) {
    defer wg.Done()
    // 遍历 test 文件夹中的内容
    f, err := os.ReadDir(folder)
    if err != nil {
        fmt.Println(err)
    }

    // 获取有效文件名，写入 c
    for _, filename := range f {
        if filename.IsDir() || strings.HasPrefix(filename.Name(), ".") {
            continue
        } else {
            c <- filename.Name()
        }
    }
    // 被 range 调用的 channel 要提前 close
    close(c)
    fmt.Println("Write filename done")
}

func MoveFile(oldfolder string, newfolder string, name string) error {
    // 一个丑陋的文件转移函数
    oldpath := oldfolder + "/" + name
    newpath := newfolder + "/" + name

    err := os.Rename(oldpath, newpath)
    return err
}

func dealInfo(target string, typeDict map[string]int, c <-chan string) {
    defer wg.Done()

    // 遍历 c 通道内的所有文件名
    for name := range c {
        sp := strings.Split(name, ".")
        suffix := sp[len(sp)-1]

        if _, ok := typeDict[suffix]; ok {
            // 如果文件夹已经存在，移动文件
            err := MoveFile(target, suffix, name)
            if err != nil {
                fmt.Println(err, "move file 1")
            }
        } else {
            // 如果文件夹不存在，创建文件夹，移动文件，打标记
            // crGuard.RLock()
            err := os.Mkdir(suffix, os.ModePerm)
            if err != nil {
                fmt.Println(err, "create folder")
            }
            // crGuard.RUnlock()

            err = MoveFile(target, suffix, name)
            if err != nil {
                fmt.Println(err, "move file 2")
            }
            typeDict[suffix] = 1
        }
    }
}

func main() {
    ff.GenFiles()

    c := make(chan string, 1000)
    typeDict := make(map[string]int)
    start := time.Now()

    wg.Add(1)
    go getInfo("./test", c)

    for i := 0; i < 16; i++ {
        wg.Add(1)
        go dealInfo("./test", typeDict, c)
    }

    wg.Wait()

    fmt.Println("time: ", time.Since(start))
}