Go1.9按行读取日志文件并处理

package mainimport (    "bufio"    "bytes"    "context"    "log"    "os"    "sync")const (    logname    = "log"    concurrent = 5                //并发处理数,可以根据物理内存调整    maxsize    = 10 * 1024 * 1024 //每次读取的大小,可以根据物理内存调整)var bufs = make([][]byte, concurrent)func main() {    var (        chs         = make(map[int]chan int)        wait        = new(sync.WaitGroup)        chct        = make(chan int, concurrent)        ctx, cancel = context.WithCancel(context.Background())    )    File, err := os.Open(logname)    if err != nil {        log.Fatalf("Open file error,%s\n", err.Error())    }    for i := 0; i < concurrent; i++ {        chct <- i        chs[i] = make(chan int)        bufs[i] = make([]byte, maxsize)        go resolvectx(ctx, wait, i, chct, chs[i])    }    var i, n, l int    for i = range chct {        n, err = File.Read(bufs[i])        if err != nil {            wait.Wait() //等待数据全部处理完毕,然后返回            break        }        for s := 1; s < n; s++ { //如果行过长,那么效率会变低            if bufs[i][n-s] == '\n' {                n = n - s + 1                File.Seek(int64(l+n), 0)                break            }        }        l += n        wait.Add(1)        chs[i] <- n    }    cancel()    close(chct)    File.Close()}func resolvectx(ctx context.Context, wait *sync.WaitGroup, index int, chct, ch chan int) {    var (        err    error        line   []byte        length int        buf    = bufio.NewReader(nil)    )    for {        select {        case <-ctx.Done():            return        case length = <-ch:            buf.Reset(bytes.NewBuffer(bufs[index][:length]))            for {                line, _, err = buf.ReadLine()                if err != nil {                    break                }                _ = line            }            chct <- index            wait.Done()        }    }}