// max requests per node is calculated as
		// total_ram / ram_per_request
		blockSize := xioutil.LargeBlock + xioutil.SmallBlock
		if legacy {
			// ram_per_request is (1MiB+32KiB) * driveCount \
			//    + 2 * 10MiB (default erasure block size v1) + 2 * 1MiB (default erasure block size v2)
			apiRequestsMaxPerNode = int(maxMem / uint64(maxSetDrives*blockSize+int(blockSizeV1*2+blockSizeV2*2)))
		} else {

	case size < fi.Erasure.BlockSize:
		// No need to allocate fully fi.Erasure.BlockSize buffer if the incoming data is smaller.
		buffer = make([]byte, size, 2*size+int64(fi.Erasure.ParityBlocks+fi.Erasure.DataBlocks-1))
	}

	if len(buffer) > int(fi.Erasure.BlockSize) {
		buffer = buffer[:fi.Erasure.BlockSize]
	}
	writers := make([]io.Writer, len(onlineDisks))
	for i, disk := range onlineDisks {
		if disk == nil {

	if totalLength == -1 {
		return -1
	}
	numShards := totalLength / e.BlockSize
	lastBlockSize := totalLength % e.BlockSize
	lastShardSize := ceilFrac(lastBlockSize, int64(e.DataBlocks))
	return numShards*e.ShardSize() + lastShardSize
}

// ShardSize - returns actual shared size from erasure blockSize.
func (e ErasureInfo) ShardSize() int64 {
	return ceilFrac(e.BlockSize, int64(e.DataBlocks))
}

	}

	if cipher, ok := cipher.(gcmAble); ok {
		return cipher.NewGCM(nonceSize, tagSize)
	}

	if cipher.BlockSize() != gcmBlockSize {
		return nil, errors.New("cipher: NewGCM requires 128-bit block cipher")
	}

	var key [gcmBlockSize]byte
	cipher.Encrypt(key[:], key[:])

func shardSize(blockSize, dataBlocks int) (sz int) {
	if dataBlocks == 0 {
		// do nothing on invalid input
		return
	}
	// Make denominator positive
	if dataBlocks < 0 {
		blockSize = -blockSize
		dataBlocks = -dataBlocks
	}
	sz = blockSize / dataBlocks
	if blockSize > 0 && blockSize%dataBlocks != 0 {
		sz++
	}
	return
}

	// per table B.3.
	zigStart, zigEnd, ah, al := int32(0), int32(blockSize-1), uint32(0), uint32(0)
	if d.progressive {
		zigStart = int32(d.tmp[1+2*nComp])
		zigEnd = int32(d.tmp[2+2*nComp])
		ah = uint32(d.tmp[3+2*nComp] >> 4)
		al = uint32(d.tmp[3+2*nComp] & 0x0f)
		if (zigStart == 0 && zigEnd != 0) || zigStart > zigEnd || blockSize <= zigEnd {
			return FormatError("bad spectral selection bounds")
		}

type cthWrapper struct {
	h constantTimeHash
}

func (c *cthWrapper) Size() int                   { return c.h.Size() }
func (c *cthWrapper) BlockSize() int              { return c.h.BlockSize() }
func (c *cthWrapper) Reset()                      { c.h.Reset() }
func (c *cthWrapper) Write(p []byte) (int, error) { return c.h.Write(p) }

				Index:      []uint8(nil),
				Checksums:  map[string]string(nil),
			},
		},
		Erasure: ErasureInfo{
			Algorithm:    "ReedSolomon",
			DataBlocks:   6,
			ParityBlocks: 6,
			BlockSize:    1048576,
			Index:        1,
			Distribution: []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12},
			Checksums:    []ChecksumInfo{{PartNumber: 1, Algorithm: 0x3, Hash: []uint8{}}},
		},
		NumVersions: 1,

	queryVals := make(url.Values)
	if opts.Serial {
		queryVals.Set("serial", "true")
	}
	queryVals.Set("blocksize", strconv.FormatUint(opts.BlockSize, 10))
	queryVals.Set("filesize", strconv.FormatUint(opts.FileSize, 10))

	respBody, err := client.callWithContext(ctx, peerRESTMethodDriveSpeedTest, queryVals, nil, -1)
	if err != nil {

func newFileInfo(object string, dataBlocks, parityBlocks int) (fi FileInfo) {
	fi.Erasure = ErasureInfo{
		Algorithm:    erasureAlgorithm,
		DataBlocks:   dataBlocks,
		ParityBlocks: parityBlocks,
		BlockSize:    blockSizeV2,
		Distribution: hashOrder(object, dataBlocks+parityBlocks),
	}
	return fi
}

// ReadMultipleReq contains information of multiple files to read from disk.
type ReadMultipleReq struct {