func bitrotShardFileSize(size int64, shardSize int64, algo BitrotAlgorithm) int64 {
	if algo != HighwayHash256S {
		return size
	}
	return ceilFrac(size, shardSize)*int64(algo.New().Size()) + size
}

// bitrotVerify a single stream of data.
func bitrotVerify(r io.Reader, wantSize, partSize int64, algo BitrotAlgorithm, want []byte, shardSize int64) error {
	if algo != HighwayHash256S {
		h := algo.New()

	switch what {
	case timePartYear:
		return FromInt(int64(t.Year())), nil
	case timePartMonth:
		return FromInt(int64(t.Month())), nil
	case timePartDay:
		return FromInt(int64(t.Day())), nil
	case timePartHour:
		return FromInt(int64(t.Hour())), nil
	case timePartMinute:
		return FromInt(int64(t.Minute())), nil
	case timePartSecond:
		return FromInt(int64(t.Second())), nil
	case timePartTimezoneHour:

	tests := []struct {
		sizes []int64
		want  map[string]uint64
	}{
		{
			sizes: []int64{100, 1000, 72_000, 100_000},
			want: map[string]uint64{
				"LESS_THAN_1024_B":         2,
				"BETWEEN_64_KB_AND_256_KB": 2,
				"BETWEEN_1024B_AND_1_MB":   2,
			},
		},
		{
			sizes: []int64{100, 1000, 2000, 100_000, 13 * humanize.MiByte},
			want: map[string]uint64{
				"LESS_THAN_1024_B":         2,

	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalnsScannerOptions(b *testing.B) {
	v := nsScannerOptions{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {

	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalLockArgs(b *testing.B) {
	v := LockArgs{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := v.UnmarshalMsg(bts)

	n, _ := buf.Write(existingData)
	w := NewWriter(buf)
	w.SetOffset(int64(n))

	for _, wt := range writeTests {
		testCreate(t, w, &wt)
	}

	if err := w.Close(); err != nil {
		t.Fatal(err)
	}

	// read it back
	r, err := NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))
	if err != nil {
		t.Fatal(err)
	}
	for i, wt := range writeTests {

}

// SizeTooSmall reader size too small
type SizeTooSmall struct {
	Want int64
	Got  int64
}

func (e SizeTooSmall) Error() string {
	return fmt.Sprintf("Size small: got %d, want %d", e.Got, e.Want)
}

// SizeTooLarge reader size too large
type SizeTooLarge struct {
	Want int64
	Got  int64
}

func (e SizeTooLarge) Error() string {

	return &streamingBitrotWriter{iow: ioutil.NopCloser(w), h: algo.New(), shardSize: shardSize, canClose: nil, closeWithErr: func(err error) {}}
}

// Returns streaming bitrot writer implementation.
func newStreamingBitrotWriter(disk StorageAPI, origvolume, volume, filePath string, length int64, algo BitrotAlgorithm, shardSize int64) io.Writer {
	h := algo.New()

	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalBaseOptions(b *testing.B) {
	v := BaseOptions{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {

func (ct ColumnType) Length() (length int64, ok bool) {
	if ct.LengthValue.Valid {
		return ct.LengthValue.Int64, true
	}
	return ct.SQLColumnType.Length()
}

// DecimalSize returns the scale and precision of a decimal type.
func (ct ColumnType) DecimalSize() (precision int64, scale int64, ok bool) {
	if ct.DecimalSizeValue.Valid {
		return ct.DecimalSizeValue.Int64, ct.ScaleValue.Int64, true
	}