Kes praktikal ujian prestasi di Golang

func countWords(filename string) (map[string]int, error) {
    file, err := os.Open(filename)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    scanner := bufio.NewScanner(file)
    scanner.Split(bufio.ScanWords)

    count := make(map[string]int)
    for scanner.Scan() {
        word := scanner.Text()
        count[word]++
    }

    if err := scanner.Err(); err != nil {
        return nil, err
    }

    return count, nil
}

func BenchmarkCountWords(b *testing.B) {
    for i := 0; i < b.N; i++ {
        _, err := countWords("/path/to/file.txt")
        if err != nil {
            b.Errorf("unexpected error: %v", err)
        }
    }
}

func countWords(filename string) (map[string]int, error) {
    file, err := os.Open(filename)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    count := make(map[string]int)

    type result struct {
        word  string
        count int
    }

    wordCh := make(chan result)
    done := make(chan struct{})

    go func() {
        for r := range wordCh {
            count[r.word] += r.count
        }
        done <- struct{}{}
    }()

    scanner := bufio.NewScanner(file)
    scanner.Split(bufio.ScanWords)

    const numWorkers = 5
    var workersWg sync.WaitGroup
    workersWg.Add(numWorkers)

    for i := 0; i < numWorkers; i++ {
        go func() {
            defer workersWg.Done()

            for scanner.Scan() {
                word := scanner.Text()
                wordCh <- result{word: word, count: 1}
            }
        }()
    }

    go func() {
        workersWg.Wait()
        close(wordCh)
    }()

    if err := scanner.Err(); err != nil {
        return nil, err
    }

    <-done

    return count, nil
}