}

func newBitrotWriter(disk StorageAPI, origvolume, volume, filePath string, length int64, algo BitrotAlgorithm, shardSize int64) io.Writer {
	if algo == HighwayHash256S {
		return newStreamingBitrotWriter(disk, origvolume, volume, filePath, length, algo, shardSize)
	}
	return newWholeBitrotWriter(disk, volume, filePath, algo, shardSize)
}

	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()

	}
	bufs := make([][]byte, len(readers))
	shardSize := int(e.ShardSize())
	var b []byte

	// We should always have enough capacity, but older objects may be bigger
	// we do not need stashbuffer for them.
	if globalBytePoolCap.Load().WidthCap() >= len(readers)*shardSize {
		// Fill buffers
		b = globalBytePoolCap.Load().Get()
		// Seed the buffers.
		for i := range bufs {
			bufs[i] = b[i*shardSize : (i+1)*shardSize]
		}
	}

	return numShards*e.ShardSize() + lastShardSize
}

// ShardFileOffset - returns the effective offset where erasure reading begins.
func (e *Erasure) ShardFileOffset(startOffset, length, totalLength int64) int64 {
	shardSize := e.ShardSize()
	shardFileSize := e.ShardFileSize(totalLength)
	endShard := (startOffset + length) / e.blockSize
	tillOffset := endShard*shardSize + shardSize
	if tillOffset > shardFileSize {

	return nil
}

// Returns whole-file bitrot writer.
func newWholeBitrotWriter(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, shardSize int64) io.WriteCloser {
	return &wholeBitrotWriter{disk, volume, filePath, shardSize, algo.New()}
}

// Implementation to verify bitrot for the whole file.
type wholeBitrotReader struct {
	disk       StorageAPI
	volume     string
	filePath   string

		writers := make([]io.Writer, len(disks))
		for i, disk := range disks {
			writers[i] = newBitrotWriter(disk, "", "testbucket", "testobject", erasure.ShardFileSize(test.size), test.algorithm, erasure.ShardSize())
		}
		_, err = erasure.Encode(context.Background(), bytes.NewReader(data), writers, buffer, erasure.dataBlocks+1)
		closeBitrotWriters(writers)
		if err != nil {