Add UUID utils

notifications/notification.go

@@ -8,8 +8,7 @@ import (
 	"github.com/safing/portbase/database"
 	"github.com/safing/portbase/database/record"
 	"github.com/safing/portbase/log"
-
-	"github.com/gofrs/uuid"
+	"github.com/safing/portbase/utils"
 )
 
 // Notification types
@@ -96,7 +95,7 @@ func notify(nType uint8, id string, msg string, actions ...Action) *Notification
 	}
 
 	if id == "" {
-		id = uuid.NewV4().String()
+		id = utils.DerivedInstanceUUID(msg).String()
 	}
 
 	n := Notification{
@@ -121,7 +120,7 @@ func (n *Notification) Save() *Notification {
 		n.Created = time.Now().Unix()
 	}
 	if n.GUID == "" {
-		n.GUID = uuid.NewV4().String()
+		n.GUID = utils.RandomUUID(n.ID).String()
 	}
 
 	// make ack notification if there are no defined actions

utils/uuid.go

@@ -0,0 +1,45 @@
+package utils
+
+import (
+	"encoding/binary"
+	"time"
+
+	"github.com/gofrs/uuid"
+)
+
+var (
+	constantUUID = uuid.Must(uuid.FromString("e8dba9f7-21e2-4c82-96cb-6586922c6422"))
+	instanceUUID = RandomUUID("instance")
+)
+
+// RandomUUID returns a new random UUID with optionally provided ns
+func RandomUUID(ns string) uuid.UUID {
+	randUUID, err := uuid.NewV4()
+	switch {
+	case err != nil:
+		// fallback
+		// should practically never happen
+		return uuid.NewV5(uuidFromTime(), ns)
+	case ns != "":
+		// mix ns into the UUID
+		return uuid.NewV5(randUUID, ns)
+	default:
+		return randUUID
+	}
+}
+
+// DerivedUUID returns a new UUID that is derived from the input only, and therefore is always reproducible.
+func DerivedUUID(input string) uuid.UUID {
+	return uuid.NewV5(constantUUID, input)
+}
+
+// DerivedInstanceUUID returns a new UUID that is derived from the input, but is unique per instance (execution) and therefore is only reproducible with the same process.
+func DerivedInstanceUUID(input string) uuid.UUID {
+	return uuid.NewV5(instanceUUID, input)
+}
+
+func uuidFromTime() uuid.UUID {
+	var timeUUID uuid.UUID
+	binary.LittleEndian.PutUint64(timeUUID[:], uint64(time.Now().UnixNano()))
+	return timeUUID
+}

utils/uuid_test.go

@@ -0,0 +1,69 @@
+package utils
+
+import (
+	"testing"
+	"time"
+
+	"github.com/gofrs/uuid"
+)
+
+func TestUUID(t *testing.T) {
+	// check randomness
+	a := RandomUUID("")
+	a2 := RandomUUID("")
+	if a.String() == a2.String() {
+		t.Error("should not match")
+	}
+
+	// check with input
+	b := RandomUUID("b")
+	b2 := RandomUUID("b")
+	if b.String() == b2.String() {
+		t.Error("should not match")
+	}
+
+	// check with long input
+	c := RandomUUID("TG8UkxS+4rVrDxHtDAaNab1CBpygzmX1g5mJA37jbQ5q2uE4rVrDxHtDAaNab1CBpygzmX1g5mJA37jbQ5q2uE")
+	c2 := RandomUUID("TG8UkxS+4rVrDxHtDAaNab1CBpygzmX1g5mJA37jbQ5q2uE4rVrDxHtDAaNab1CBpygzmX1g5mJA37jbQ5q2uE")
+	if c.String() == c2.String() {
+		t.Error("should not match")
+	}
+
+	// check for nanosecond precision
+	d := uuidFromTime()
+	time.Sleep(2 * time.Nanosecond)
+	d2 := uuidFromTime()
+	if d.String() == d2.String() {
+		t.Error("should not match")
+	}
+
+	// check mixing
+	timeUUID := uuidFromTime()
+	e := uuid.NewV5(timeUUID, "e")
+	e2 := uuid.NewV5(timeUUID, "e2")
+	if e.String() == e2.String() {
+		t.Error("should not match")
+	}
+
+	// check deriving
+	f := DerivedUUID("f")
+	f2 := DerivedUUID("f")
+	f3 := DerivedUUID("f3")
+	if f.String() != f2.String() {
+		t.Error("should match")
+	}
+	if f.String() == f3.String() {
+		t.Error("should not match")
+	}
+
+	// check instance deriving
+	g := DerivedInstanceUUID("g")
+	g2 := DerivedInstanceUUID("g")
+	g3 := DerivedInstanceUUID("g3")
+	if g.String() != g2.String() {
+		t.Error("should match")
+	}
+	if g.String() == g3.String() {
+		t.Error("should not match")
+	}
+}