Merge branch 'master' into monotonic_clock

.travis.yml

@@ -1,8 +1,12 @@
 language: go
 go:
-    - 1.4
-    - 1.5
-    - 1.6
+    - 1.11.x
+    - 1.12.x
 install:
-      - go get github.com/bwmarrin/flake
-      - go get -v .
+    - go get -v .
+    - go get -v golang.org/x/lint/golint
+script:
+    - diff <(gofmt -d .) <(echo -n)
+    - go vet -x ./...
+    - golint -set_exit_status ./...
+    - go test -v -race ./...

README.md

@@ -135,7 +135,7 @@ To benchmark the generator on your system run the following command inside the
 snowflake package directory.
 
 ```sh
-go test -bench=.
+go test -run=^$ -bench=.
 ```
 
 If your curious, check out this commit that shows benchmarks that compare a few 

snowflake.go

@@ -18,19 +18,21 @@ var (
 	// Note: add time.Duration to time.Now() to make sure we use the monotonic clock if available.
 	Epoch = curTime.Add(time.Date(2010, time.November, 4, 1, 42, 54, 0, time.UTC).Sub(curTime))
 
-	// Number of bits to use for Node
+	// NodeBits holds the number of bits to use for Node
 	// Remember, you have a total 22 bits to share between Node/Step
 	NodeBits uint8 = 10
 
-	// Number of bits to use for Step
+	// StepBits holds the number of bits to use for Step
 	// Remember, you have a total 22 bits to share between Node/Step
 	StepBits uint8 = 12
 
+	// DEPRECATED: the below four variables will be removed in a future release.
+	mu        sync.Mutex
 	nodeMax   int64 = -1 ^ (-1 << NodeBits)
-	nodeMask  int64 = nodeMax << StepBits
+	nodeMask        = nodeMax << StepBits
 	stepMask  int64 = -1 ^ (-1 << StepBits)
-	timeShift uint8 = NodeBits + StepBits
-	nodeShift uint8 = StepBits
+	timeShift       = NodeBits + StepBits
+	nodeShift       = StepBits
 )
 
 const encodeBase32Map = "ybndrfg8ejkmcpqxot1uwisza345h769"
@@ -81,6 +83,12 @@ type Node struct {
 	time time.Duration
 	node int64
 	step int64
+
+	nodeMax   int64
+	nodeMask  int64
+	stepMask  int64
+	timeShift uint8
+	nodeShift uint8
 }
 
 // An ID is a custom type used for a snowflake ID.  This is used so we can
@@ -92,17 +100,28 @@ type ID int64
 func NewNode(node int64) (*Node, error) {
 
 	// re-calc in case custom NodeBits or StepBits were set
+	// DEPRECATED: the below block will be removed in a future release.
+	mu.Lock()
 	nodeMax = -1 ^ (-1 << NodeBits)
 	nodeMask = nodeMax << StepBits
 	stepMask = -1 ^ (-1 << StepBits)
 	timeShift = NodeBits + StepBits
 	nodeShift = StepBits
+	mu.Unlock()
 
-	if node < 0 || node > nodeMax {
-		return nil, errors.New("Node number must be between 0 and " + strconv.FormatInt(nodeMax, 10))
+	n := Node{}
+	n.node = node
+	n.nodeMax = -1 ^ (-1 << NodeBits)
+	n.nodeMask = n.nodeMax << StepBits
+	n.stepMask = -1 ^ (-1 << StepBits)
+	n.timeShift = NodeBits + StepBits
+	n.nodeShift = StepBits
+
+	if n.node < 0 || n.node > n.nodeMax {
+		return nil, errors.New("Node number must be between 0 and " + strconv.FormatInt(n.nodeMax, 10))
 	}
 
-	return &Node{node: node}, nil
+	return &n, nil
 }
 
 // Generate creates and returns a unique snowflake ID
@@ -113,7 +132,7 @@ func (n *Node) Generate() ID {
 	now := time.Since(Epoch)
 
 	if now-n.time < time.Millisecond {
-		n.step = (n.step + 1) & stepMask
+		n.step = (n.step + 1) & n.stepMask
 
 		if n.step == 0 {
 			for now-n.time < time.Millisecond {
@@ -126,8 +145,8 @@ func (n *Node) Generate() ID {
 
 	n.time = now
 
-	r := ID((now.Nanoseconds()/1000000)<<timeShift |
-		(n.node << nodeShift) |
+	r := ID((now.Nanoseconds()/1000000)<<n.timeShift |
+		(n.node << n.nodeShift) |
 		(n.step),
 	)
 
@@ -251,16 +270,19 @@ func (f ID) IntBytes() [8]byte {
 }
 
 // Time returns an int64 unix timestamp in miliseconds of the snowflake ID time
+// DEPRECATED: the below function will be removed in a future release.
 func (f ID) Time() int64 {
 	return (int64(f) >> timeShift) + (Epoch.UnixNano() / 1000000)
 }
 
 // Node returns an int64 of the snowflake ID node number
+// DEPRECATED: the below function will be removed in a future release.
 func (f ID) Node() int64 {
 	return int64(f) & nodeMask >> nodeShift
 }
 
 // Step returns an int64 of the snowflake step (or sequence) number
+// DEPRECATED: the below function will be removed in a future release.
 func (f ID) Step() int64 {
 	return int64(f) & stepMask
 }

snowflake_test.go

@@ -6,6 +6,25 @@ import (
 	"testing"
 )
 
+// I feel like there's probably a better way
+func TestRace(t *testing.T) {
+
+	node, _ := NewNode(1)
+
+	go func() {
+		for i := 0; i < 1000000000; i++ {
+
+			NewNode(1)
+		}
+	}()
+
+	for i := 0; i < 4000; i++ {
+
+		node.Generate()
+	}
+
+}
+
 func TestMarshalJSON(t *testing.T) {
 	id := ID(13587)
 	expected := "\"13587\""
@@ -31,7 +50,7 @@ func TestMarshalsIntBytes(t *testing.T) {
 func TestUnmarshalJSON(t *testing.T) {
 	tt := []struct {
 		json        string
-		expectedId  ID
+		expectedID  ID
 		expectedErr error
 	}{
 		{`"13587"`, 13587, nil},
@@ -46,8 +65,8 @@ func TestUnmarshalJSON(t *testing.T) {
 			t.Errorf("Expected to get error '%s' decoding JSON, but got '%s'", tc.expectedErr, err)
 		}
 
-		if id != tc.expectedId {
-			t.Errorf("Expected to get ID '%s' decoding JSON, but got '%s'", tc.expectedId, id)
+		if id != tc.expectedID {
+			t.Errorf("Expected to get ID '%s' decoding JSON, but got '%s'", tc.expectedID, id)
 		}
 	}
 }
@@ -112,6 +131,7 @@ func TestBase58(t *testing.T) {
 		}
 	}
 }
+
 func BenchmarkParseBase58(b *testing.B) {
 
 	node, _ := NewNode(1)
@@ -149,6 +169,20 @@ func BenchmarkGenerate(b *testing.B) {
 	}
 }
 
+func BenchmarkGenerateMaxSequence(b *testing.B) {
+
+	NodeBits = 1
+	StepBits = 21
+	node, _ := NewNode(1)
+
+	b.ReportAllocs()
+
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		_ = node.Generate()
+	}
+}
+
 func BenchmarkUnmarshal(b *testing.B) {
 	// Generate the ID to unmarshal
 	node, _ := NewNode(1)