Use int64

README.md

@@ -27,7 +27,7 @@ Installation
 ------------
 
 ```
-go get github.com/sony/sonyflake
+go get github.com/sony/sonyflake/v2
 ```
 
 Usage
@@ -44,8 +44,8 @@ You can configure Sonyflake by the struct Settings:
 ```go
 type Settings struct {
 	StartTime      time.Time
-	MachineID      func() (uint16, error)
-	CheckMachineID func(uint16) bool
+	MachineID      func() (int64, error)
+	CheckMachineID func(int64) bool
 }
 ```
 
@@ -65,16 +65,12 @@ type Settings struct {
 In order to get a new unique ID, you just have to call the method NextID.
 
 ```go
-func (sf *Sonyflake) NextID() (uint64, error)
+func (sf *Sonyflake) NextID() (int64, error)
 ```
 
 NextID can continue to generate IDs for about 174 years from StartTime.
 But after the Sonyflake time is over the limit, NextID returns an error.
 
-> **Note:**
-> Sonyflake currently does not use the most significant bit of IDs,
-> so you can convert Sonyflake IDs from `uint64` to `int64` safely.
-
 AWS VPC and Docker
 ------------------
 

v2/awsutil/awsutil.go

@@ -34,13 +34,13 @@ func amazonEC2PrivateIPv4() (net.IP, error) {
 // AmazonEC2MachineID retrieves the private IP address of the Amazon EC2 instance
 // and returns its lower 16 bits.
 // It works correctly on Docker as well.
-func AmazonEC2MachineID() (uint16, error) {
+func AmazonEC2MachineID() (int64, error) {
 	ip, err := amazonEC2PrivateIPv4()
 	if err != nil {
 		return 0, err
 	}
 
-	return uint16(ip[2])<<8 + uint16(ip[3]), nil
+	return int64(uint16(ip[2])<<8 + uint16(ip[3])), nil
 }
 
 // TimeDifference returns the time difference between the localhost and the given NTP server.

v2/sonyflake.go

@@ -39,8 +39,8 @@ const (
 // If CheckMachineID is nil, no validation is done.
 type Settings struct {
 	StartTime      time.Time
-	MachineID      func() (uint16, error)
-	CheckMachineID func(uint16) bool
+	MachineID      func() (int64, error)
+	CheckMachineID func(int64) bool
 }
 
 // Sonyflake is a distributed unique ID generator.
@@ -48,8 +48,8 @@ type Sonyflake struct {
 	mutex       *sync.Mutex
 	startTime   int64
 	elapsedTime int64
-	sequence    uint16
-	machineID   uint16
+	sequence    int64
+	machineID   int64
 }
 
 var (
@@ -73,10 +73,10 @@ func New(st Settings) (*Sonyflake, error) {
 
 	sf := new(Sonyflake)
 	sf.mutex = new(sync.Mutex)
-	sf.sequence = uint16(1<<BitLenSequence - 1)
+	sf.sequence = int64(1<<BitLenSequence - 1)
 
 	if st.StartTime.IsZero() {
-		sf.startTime = toSonyflakeTime(time.Date(2014, 9, 1, 0, 0, 0, 0, time.UTC))
+		sf.startTime = toSonyflakeTime(time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC))
 	} else {
 		sf.startTime = toSonyflakeTime(st.StartTime)
 	}
@@ -110,8 +110,10 @@ func NewSonyflake(st Settings) *Sonyflake {
 
 // NextID generates a next unique ID.
 // After the Sonyflake time overflows, NextID returns an error.
-func (sf *Sonyflake) NextID() (uint64, error) {
-	const maskSequence = uint16(1<<BitLenSequence - 1)
+// NextID generates a next unique ID as int64.
+// After the Sonyflake time overflows, NextID returns an error.
+func (sf *Sonyflake) NextID() (int64, error) {
+	const maskSequence = int64(1<<BitLenSequence - 1)
 
 	sf.mutex.Lock()
 	defer sf.mutex.Unlock()
@@ -147,14 +149,14 @@ func sleepTime(overtime int64) time.Duration {
 		time.Duration(time.Now().UTC().UnixNano()%sonyflakeTimeUnit)
 }
 
-func (sf *Sonyflake) toID() (uint64, error) {
+func (sf *Sonyflake) toID() (int64, error) {
 	if sf.elapsedTime >= 1<<BitLenTime {
 		return 0, ErrOverTimeLimit
 	}
 
-	return uint64(sf.elapsedTime)<<(BitLenSequence+BitLenMachineID) |
-		uint64(sf.sequence)<<BitLenMachineID |
-		uint64(sf.machineID), nil
+	return sf.elapsedTime<<(BitLenSequence+BitLenMachineID) |
+		sf.sequence<<BitLenMachineID |
+		sf.machineID, nil
 }
 
 func privateIPv4(interfaceAddrs types.InterfaceAddrs) (net.IP, error) {
@@ -183,43 +185,43 @@ func isPrivateIPv4(ip net.IP) bool {
 		(ip[0] == 10 || ip[0] == 172 && (ip[1] >= 16 && ip[1] < 32) || ip[0] == 192 && ip[1] == 168 || ip[0] == 169 && ip[1] == 254)
 }
 
-func lower16BitPrivateIP(interfaceAddrs types.InterfaceAddrs) (uint16, error) {
+func lower16BitPrivateIP(interfaceAddrs types.InterfaceAddrs) (int64, error) {
 	ip, err := privateIPv4(interfaceAddrs)
 	if err != nil {
 		return 0, err
 	}
 
-	return uint16(ip[2])<<8 + uint16(ip[3]), nil
+	return int64(ip[2])<<8 + int64(ip[3]), nil
 }
 
 // ElapsedTime returns the elapsed time when the given Sonyflake ID was generated.
-func ElapsedTime(id uint64) time.Duration {
+func ElapsedTime(id int64) time.Duration {
 	return time.Duration(elapsedTime(id) * sonyflakeTimeUnit)
 }
 
-func elapsedTime(id uint64) uint64 {
+func elapsedTime(id int64) int64 {
 	return id >> (BitLenSequence + BitLenMachineID)
 }
 
 // SequenceNumber returns the sequence number of a Sonyflake ID.
-func SequenceNumber(id uint64) uint64 {
-	const maskSequence = uint64((1<<BitLenSequence - 1) << BitLenMachineID)
-	return id & maskSequence >> BitLenMachineID
+func SequenceNumber(id int64) int64 {
+	const maskSequence = int64((1<<BitLenSequence - 1) << BitLenMachineID)
+	return (id & maskSequence) >> BitLenMachineID
 }
 
 // MachineID returns the machine ID of a Sonyflake ID.
-func MachineID(id uint64) uint64 {
-	const maskMachineID = uint64(1<<BitLenMachineID - 1)
+func MachineID(id int64) int64 {
+	const maskMachineID = int64(1<<BitLenMachineID - 1)
 	return id & maskMachineID
 }
 
 // Decompose returns a set of Sonyflake ID parts.
-func Decompose(id uint64) map[string]uint64 {
+func Decompose(id int64) map[string]int64 {
 	msb := id >> 63
 	time := elapsedTime(id)
 	sequence := SequenceNumber(id)
 	machineID := MachineID(id)
-	return map[string]uint64{
+	return map[string]int64{
 		"id":         id,
 		"msb":        msb,
 		"time":       time,

v2/sonyflake_test.go

@@ -15,7 +15,7 @@ import (
 var sf *Sonyflake
 
 var startTime int64
-var machineID uint64
+var machineID int64
 
 func init() {
 	var st Settings
@@ -29,10 +29,10 @@ func init() {
 	startTime = toSonyflakeTime(st.StartTime)
 
 	ip, _ := lower16BitPrivateIP(defaultInterfaceAddrs)
-	machineID = uint64(ip)
+	machineID = int64(ip)
 }
 
-func nextID(t *testing.T) uint64 {
+func nextID(t *testing.T) int64 {
 	id, err := sf.NextID()
 	if err != nil {
 		t.Fatal("id not generated")
@@ -58,7 +58,7 @@ func TestNew(t *testing.T) {
 		{
 			name: "failure: machine ID",
 			settings: Settings{
-				MachineID: func() (uint16, error) {
+				MachineID: func() (int64, error) {
 					return 0, genError
 				},
 			},
@@ -67,7 +67,7 @@ func TestNew(t *testing.T) {
 		{
 			name: "failure: invalid machine ID",
 			settings: Settings{
-				CheckMachineID: func(uint16) bool {
+				CheckMachineID: func(int64) bool {
 					return false
 				},
 			},
@@ -125,8 +125,8 @@ func currentTime() int64 {
 
 func TestSonyflakeFor10Sec(t *testing.T) {
 	var numID uint32
-	var lastID uint64
-	var maxSequence uint64
+	var lastID int64
+	var maxSequence int64
 
 	initial := currentTime()
 	current := initial
@@ -179,7 +179,7 @@ func TestSonyflakeInParallel(t *testing.T) {
 	runtime.GOMAXPROCS(numCPU)
 	fmt.Println("number of cpu:", numCPU)
 
-	consumer := make(chan uint64)
+	consumer := make(chan int64)
 
 	const numID = 10000
 	generate := func() {
@@ -193,7 +193,7 @@ func TestSonyflakeInParallel(t *testing.T) {
 		go generate()
 	}
 
-	set := make(map[uint64]struct{})
+	set := make(map[int64]struct{})
 	for i := 0; i < numID*numGenerator; i++ {
 		id := <-consumer
 		if _, ok := set[id]; ok {
@@ -270,7 +270,7 @@ func TestPrivateIPv4(t *testing.T) {
 func TestLower16BitPrivateIP(t *testing.T) {
 	testCases := []struct {
 		description    string
-		expected       uint16
+		expected       int64
 		interfaceAddrs types.InterfaceAddrs
 		error          string
 	}{