clean up id generation, add prefixes to IDs.

client.go

@@ -98,7 +98,7 @@ type Client struct {
 // tear down clients upon quitting.
 func New(ctx context.Context, config Config) *Client {
 	client := &Client{
-		id:         generateClientID(),
+		id:         generateClientID("C"),
 		values:     make(map[string]interface{}),
 		events:     make(chan *Event, 64),
 		sends:      make(chan string, 64),
@@ -672,7 +672,7 @@ func (client *Client) AddTarget(target Target) (id string, err error) {
 		}
 	}
 
-	id = generateClientID()
+	id = generateClientID("T")
 	client.targets = append(client.targets, target)
 	client.targetIds[target] = id
 
@@ -1493,22 +1493,16 @@ func (client *Client) handleInTarget(target Target, event *Event) {
 	client.mutex.RUnlock()
 }
 
-func generateClientID() string {
-	bytes := make([]byte, 12)
-	_, err := rand.Read(bytes)
+func generateClientID(prefix string) string {
+	buffer := [12]byte{}
+	_, err := rand.Read(buffer[:])
 
 	// Ugly fallback if crypto rand doesn't work.
 	if err != nil {
-		rng := mathRand.NewSource(time.Now().UnixNano())
-		result := strconv.FormatInt(rng.Int63(), 16)
-		for len(result) < 24 {
-			result += strconv.FormatInt(rng.Int63(), 16)
-		}
-
-		return result[:24]
+		mathRand.Read(buffer[:])
 	}
 
-	binary.BigEndian.PutUint32(bytes[4:], uint32(time.Now().Unix()))
+	binary.BigEndian.PutUint32(buffer[4:], uint32(time.Now().Unix()))
 
-	return hex.EncodeToString(bytes)
+	return prefix + hex.EncodeToString(buffer[:])[1:]
 }

go.sum

@@ -0,0 +1,10 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=