headerLength := len(header)
	payloadLength := 0
	totalLength := totalByteLength(headerLength, payloadLength)

	buf = new(bytes.Buffer)
	binary.Write(buf, binary.BigEndian, uint32(totalLength))
	binary.Write(buf, binary.BigEndian, uint32(headerLength))
	prelude := buf.Bytes()
	binary.Write(buf, binary.BigEndian, crc32.ChecksumIEEE(prelude))
	buf.Write(header)
	message := buf.Bytes()

type LimitWriter struct {
	io.Writer
	skipBytes int64
	wLimit    int64
}

// Write implements the io.Writer interface limiting upto
// configured length, also skips the first N bytes.
func (w *LimitWriter) Write(p []byte) (n int, err error) {
	n = len(p)
	var n1 int
	if w.skipBytes > 0 {
		if w.skipBytes >= int64(len(p)) {
			w.skipBytes -= int64(len(p))
			return n, nil
		}
		p = p[w.skipBytes:]

)

// timeouts that are dynamically adapted based on actual usage results
type dynamicTimeout struct {
	timeout       int64
	minimum       int64
	entries       int64
	log           [dynamicTimeoutLogSize]time.Duration
	mutex         sync.Mutex
	retryInterval time.Duration
}

type dynamicTimeoutOpts struct {
	timeout       time.Duration

	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalmetacache(b *testing.B) {
	v := metacache{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := v.UnmarshalMsg(bts)

		{bucketNames[0], objectNames[0], uploadIDs[0], 4, "mnop", "e132e96a5ddad6da8b07bba6f6131fef", int64(len("abcd"))},
		// Part with size larger than 5Mb.
		{bucketNames[0], objectNames[0], uploadIDs[0], 5, string(validPart), validPartMD5, int64(len(validPart))},
		{bucketNames[0], objectNames[0], uploadIDs[0], 6, string(validPart), validPartMD5, int64(len(validPart))},

type Stats struct {
	TotalEvents        int64 // Deprecated
	EventsSkipped      int64
	CurrentQueuedCalls int64 // Deprecated
	EventsErrorsTotal  int64 // Deprecated
	CurrentSendCalls   int64 // Deprecated

	TargetStats map[TargetID]TargetStat
}

// TargetStat is the stats of a single target.
type TargetStat struct {

	bts := make([]byte, 0, v.Msgsize())
	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalDailyAllTierStats(b *testing.B) {
	v := DailyAllTierStats{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {

	bts, _ = v.MarshalMsg(bts[0:0])
	b.SetBytes(int64(len(bts)))
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		bts, _ = v.MarshalMsg(bts[0:0])
	}
}

func BenchmarkUnmarshalBucketBandwidthReport(b *testing.B) {
	v := BucketBandwidthReport{}
	bts, _ := v.MarshalMsg(nil)
	b.ReportAllocs()
	b.SetBytes(int64(len(bts)))
	b.ResetTimer()
	for i := 0; i < b.N; i++ {

	k0, k1 := binary.LittleEndian.Uint64(id[0:8]), binary.LittleEndian.Uint64(id[8:16])
	sum64 := siphash.Hash(k0, k1, []byte(key))
	return int(sum64 % uint64(cardinality))
}

func crcHashMod(key string, cardinality int) int {
	if cardinality <= 0 {
		return -1
	}
	keyCrc := crc32.Checksum([]byte(key), crc32.IEEETable)
	return int(keyCrc % uint32(cardinality))
}

// are not empty then it will check whether the computed
// match the reference values.
type Reader struct {
	src         io.Reader
	bytesRead   int64
	expectedMin int64
	expectedMax int64

	size       int64
	actualSize int64

	checksum      etag.ETag
	contentSHA256 []byte

	// Content checksum
	contentHash   Checksum
	contentHasher hash.Hash
	disableMD5    bool