func reflectionMapping(fr *mmap.ReaderAt, typeSize int) []int32 {
_bytes := make([]byte, fr.Len(), fr.Len())
_, err := fr.ReadAt(_bytes, 0)
if err != nil {
fmt.Printf("got error msg: %s", err)
}
header := *(*reflect.SliceHeader)(unsafe.Pointer(&_bytes))
// The length and capacity of the slice are different.
header.Len /= typeSize // 8 + 4 + 1
header.Cap /= typeSize // 8 + 4 + 1
// Convert slice header to a []byte
return *(*[]int32)(unsafe.Pointer(&header))
}
func copingMapping(fr mmap.ReaderAt) []int32 {
_bytes := make([]byte, fr.Len(), fr.Len())
_, err := fr.ReadAt(_bytes, 0)
if err != nil {
fmt.Printf("got error msg: %s", err)
}
data := make([]int32, fr.Len()/4, fr.Len()/4)
buf := bytes.NewBuffer(_bytes)
binary.Read(buf, binary.LittleEndian, &data)
return data
}