func parallelRead() (int, error) {
mf, err := mmap.Open(bigFile)
if err != nil {
return 0, err
}
defer mf.Close()
ch := make(chan int, 4)
whole := mf.Data()
for i := 0; i < 4; i++ {
go func(b []byte) {
ch <- countZero(b)
}(whole[i*unitSize : (i+1)*unitSize-1])
}
cnt := 0
for i := 0; i < 4; i++ {
select {
case c := <-ch:
cnt += c
}
}
return cnt, nil
}
func sequentialRead() (int, error) {
mf, err := mmap.Open(bigFile)
if err != nil {
return 0, err
}
defer mf.Close()
return countZero(mf.Data()), nil
}