{dataBlocks: 6, onDisks: 12, offDisks: 0, blocksize: int64(blockSizeV2), data: int64(2 * blockSizeV2), offset: 512, length: int64(blockSizeV2) + 8*1024, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false},           // 30

	{dataBlocks: 5, disks: 10, offDisks: 3, badDisks: 1, badStaleDisks: 0, blocksize: int64(blockSizeV2), size: oneMiByte, algorithm: DefaultBitrotAlgorithm, shouldFail: false},  // 3

					testReadFrom{fileOps{
						int64(1e10 - blockSize),
						strings.Repeat("\x00", blockSize-100) + strings.Repeat("0123456789", 10),
						int64(1e10 - blockSize),
						strings.Repeat("\x00", blockSize-100) + strings.Repeat("0123456789", 10),
						int64(1e10 - blockSize),
						strings.Repeat("\x00", blockSize-100) + strings.Repeat("0123456789", 10),
						int64(1e10 - blockSize),

	{dataBlocks: 4, onDisks: 8, offDisks: 2, blocksize: int64(blockSizeV2), data: oneMiByte, offset: 2, algorithm: DefaultBitrotAlgorithm, shouldFail: false, shouldFailQuorum: false},                 // 2

	}
	w := metacacheWriter{
		mw:        nil,
		blockSize: blockSize,
	}
	w.creator = func() error {
		s2w := s2.NewWriter(out, s2.WriterBlockSize(blockSize), s2.WriterConcurrency(2))
		w.mw = msgp.NewWriter(s2w)
		w.creator = nil
		if err := w.mw.WriteByte(metacacheStreamVersion); err != nil {
			return err
		}

		w.closer = func() (err error) {
			defer func() {
				cerr := s2w.Close()

// Erasure - erasure encoding details.
type Erasure struct {
	encoder                  func() reedsolomon.Encoder
	dataBlocks, parityBlocks int
	blockSize                int64
}

// NewErasure creates a new ErasureStorage.
func NewErasure(ctx context.Context, dataBlocks, parityBlocks int, blockSize int64) (e Erasure, err error) {
	// Check the parameters for sanity now.
	if dataBlocks <= 0 || parityBlocks < 0 {

			blockLength = e.blockSize - blockOffset
		case block == endBlock:
			blockOffset = 0
			blockLength = (offset + length) % e.blockSize
		default:
			blockOffset = 0
			blockLength = e.blockSize
		}
		if blockLength == 0 {
			break
		}

		var err error
		bufs, err = reader.Read(bufs)
		if len(bufs) > 0 {
			// Set only if there are be enough data for reconstruction.

func (u UUIDHash) Reset() {
	return
}

// Size -  implement hash.Hash Size
func (u UUIDHash) Size() int {
	return len(u.uuid)
}

// BlockSize -  implement hash.Hash BlockSize
func (u UUIDHash) BlockSize() int {
	return md5.BlockSize
}

var _ hash.Hash = &UUIDHash{}

// NewUUIDHash - new UUIDHash
func NewUUIDHash(uuid []byte) *UUIDHash {
	return &UUIDHash{uuid: uuid}

	DataBlocks int `json:"data"`
	// ParityBlocks is the number of parity blocks for erasure-coding
	ParityBlocks int `json:"parity"`
	// BlockSize is the size of one erasure-coded block
	BlockSize int64 `json:"blockSize"`
	// Index is the index of the current disk
	Index int `json:"index"`
	// Distribution is the distribution of the data and parity blocks
	Distribution []int `json:"distribution"`

		}
		var (
			hash = algorithm.New()
			msg  = make([]byte, 0, hash.Size()*hash.BlockSize())
			sum  = make([]byte, 0, hash.Size())
		)
		for i := 0; i < hash.Size()*hash.BlockSize(); i += hash.Size() {
			hash.Write(msg)
			sum = hash.Sum(sum[:0])
			msg = append(msg, sum...)
			hash.Reset()
		}
		if !bytes.Equal(sum, checksum) {