if err != nil {
		return err
	}
	if hashsize >= (max / 4) {
		return nil
	}

	// sysfs is expected to be mounted as 'rw'. However, it may be
	// unexpectedly mounted as 'ro' by docker because of a known docker
	// issue (https://github.com/docker/docker/issues/24000). Setting
	// conntrack will fail when sysfs is readonly. When that happens, we
	// don't set conntrack hashsize and return a special error

@Immutable
public class HashCodeSerializer extends AbstractSerializer<HashCode> {
    @Override
    public HashCode read(Decoder decoder) throws IOException {
        byte hashSize = decoder.readByte();
        byte[] hash = new byte[hashSize];
        decoder.readBytes(hash);
        return HashCode.fromBytes(hash);
    }

    @Override
    public void write(Encoder encoder, HashCode value) throws IOException {

	t.W = int((n + 1) << uint(level))
	return t, int(n<<uint(level)) * HashSize, int((n+1)<<uint(level)) * HashSize
}

// HashFromTile returns the hash at the given storage index,
// provided that t == TileForIndex(t.H, index) or a wider version,
// and data is t's tile data (of length at least t.W*HashSize).
func HashFromTile(t Tile, data []byte, index int64) (Hash, error) {

	grid := make([][hashSize]int, n)

	for z := 0; z < REP; z++ {
		// pick a random key, hash it
		k.random(r)
		h := k.hash()

		// flip each bit, hash & compare the results
		for i := 0; i < n; i++ {
			k.flipBit(i)
			d := h ^ k.hash()
			k.flipBit(i)

			// record the effects of that bit flip
			g := &grid[i]
			for j := 0; j < hashSize; j++ {
				g[j] += int(d & 1)

	grid := make([][hashSize]int, n)

	for z := 0; z < REP; z++ {
		// pick a random key, hash it
		k.random(r)
		h := k.hash()

		// flip each bit, hash & compare the results
		for i := 0; i < n; i++ {
			k.flipBit(i)
			d := h ^ k.hash()
			k.flipBit(i)

			// record the effects of that bit flip
			g := &grid[i]
			for j := 0; j < hashSize; j++ {
				g[j] += int(d & 1)

	SymIdx uint32
}

func (s SymRef) IsZero() bool { return s == SymRef{} }

// Hash64
type Hash64Type [Hash64Size]byte

const Hash64Size = 8

// Hash
type HashType [HashSize]byte

const HashSize = 16 // truncated SHA256

// Relocation.
//
// Serialized format:
//
//	Reloc struct {
//	   Off  int32
//	   Siz  uint8
//	   Type uint16
//	   Add  int64
//	   Sym  SymRef

	// stop things from getting too large.
	maxFlateBlockTokens = 1 << 14
	maxStoreBlockSize   = 65535
	hashBits            = 17 // After 17 performance degrades
	hashSize            = 1 << hashBits
	hashMask            = (1 << hashBits) - 1
	maxHashOffset       = 1 << 24

	skipNever = math.MaxInt32
)

type compressionLevel struct {