if err != nil {
		logger.LogOnceIf(ctx, fmt.Errorf("%s, using default of 10s", err.Error()), "refresh-kms-master-key")
		cacheDuration = defaultCacheDuration
	}
	if cacheDuration < time.Second {
		logger.LogOnceIf(ctx, errors.New("cache duration is less than 1s, using default of 10s"), "refresh-kms-master-key")
		cacheDuration = defaultCacheDuration
	}
	timer := time.NewTimer(cacheDuration)
	defer timer.Stop()

			// walking the tree and copying it piecewise. If the directory tree
			// contains nested modules this could push a lot of unnecessary contents,
			// but for the golang.org/x repos it seems to be significantly (~2x)
			// faster than copying one file at a time (via filepath.WalkDir),
			// apparently due to high latency in 'adb' commands.
			if err := adb("push", modDir, deviceModDir); err != nil {
				return 0, err
			}
		} else {

// converted to int they correspond to the rune size that was read.
type readOp int8

// Don't use iota for these, as the values need to correspond with the
// names and comments, which is easier to see when being explicit.
const (
	opRead      readOp = -1 // Any other read operation.
	opInvalid   readOp = 0  // Non-read operation.
	opReadRune1 readOp = 1  // Read rune of size 1.

	"github.com/tinylib/msgp/msgp"
	"github.com/valyala/bytebufferpool"
)

// metadata stream format:
//
// The stream is s2 compressed.
// https://github.com/klauspost/compress/tree/master/s2#s2-compression
// This ensures integrity and reduces the size typically by at least 50%.
//
// All stream elements are msgpack encoded.
//
// 1 Integer, metacacheStreamVersion of the writer.

// This function currently supports
// - CRCMOD
// - SIPMOD
// - all new algos.
func sipHashMod(key string, cardinality int, id [16]byte) int {
	if cardinality <= 0 {
		return -1
	}
	// use the faster version as per siphash docs
	// https://github.com/dchest/siphash#usage
	k0, k1 := binary.LittleEndian.Uint64(id[0:8]), binary.LittleEndian.Uint64(id[8:16])
	sum64 := siphash.Hash(k0, k1, []byte(key))

	if cs == nil {
		return nil
	}
	r.contentHash = *cs
	if ignoreValue {
		// Do not validate, but allow for transfer
		return nil
	}

	r.contentHasher = cs.Type.Hasher()
	if r.contentHasher == nil {
		return ErrInvalidChecksum
	}
	return nil
}

func (r *Reader) Read(p []byte) (int, error) {
	n, err := r.src.Read(p)
	r.bytesRead += int64(n)
	if r.sha256 != nil {

	"istio.io/istio/pkg/util/sets"
	dep "istio.io/istio/tools/istio-iptables/pkg/dependencies"
)

var log = istiolog.RegisterScope("ambient", "ambient controller")

// Adapts CNI to ztunnel server. decoupled from k8s for easier integration testing.
type NetServer struct {
	ztunnelServer        ZtunnelServer
	currentPodSnapshot   *podNetnsCache
	iptablesConfigurator *iptables.IptablesConfigurator
	podNs                PodNetnsFinder

		return metaCacheEntriesSorted{o: m}
	}
	sort.Slice(m, m.less)
	return metaCacheEntriesSorted{o: m}
}

// isSorted returns whether the objects are sorted.
// This is usually orders of magnitude faster than actually sorting.
func (m metaCacheEntries) isSorted() bool {
	return sort.SliceIsSorted(m, m.less)
}

// shallowClone will create a shallow clone of the array objects,

	borrowed []hash.Hash
}

// Borrow a single hasher.
func (h *HashBorrower) Borrow() hash.Hash {
	hasher := h.pool.Get().(hash.Hash)
	h.borrowed = append(h.borrowed, hasher)
	hasher.Reset()
	return hasher
}

// ReturnAll will return all borrowed hashes.
func (h *HashBorrower) ReturnAll() {
	for _, hasher := range h.borrowed {
		h.pool.Put(hasher)
	}
	h.borrowed = nil
}

}

// Matches returns whether given content matches c.
func (c Checksum) Matches(content []byte) error {
	if len(c.Encoded) == 0 {
		return nil
	}
	hasher := c.Type.Hasher()
	_, err := hasher.Write(content)
	if err != nil {
		return err
	}
	sum := hasher.Sum(nil)
	if !bytes.Equal(sum, c.Raw) {
		return ChecksumMismatch{
			Want: c.Encoded,
			Got:  base64.StdEncoding.EncodeToString(sum),
		}
	}