uuid

common/uuid/uuid.go

@@ -0,0 +1,75 @@
+package uuid
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+)
+
+var (
+	byteGroups = []int{8, 4, 4, 4, 12}
+
+	InvalidID = errors.New("Invalid ID.")
+)
+
+type UUID struct {
+	byteValue   [16]byte
+	stringValue string
+}
+
+func (this *UUID) String() string {
+	return this.stringValue
+}
+
+func (this *UUID) Bytes() []byte {
+	return this.byteValue[:]
+}
+
+func bytesToString(bytes [16]byte) string {
+	result := hex.EncodeToString(bytes[0 : byteGroups[0]/2])
+	start := byteGroups[0] / 2
+	for i := 1; i < len(byteGroups); i++ {
+		nBytes := byteGroups[i] / 2
+		result += "-"
+		result += hex.EncodeToString(bytes[start : start+nBytes])
+		start += nBytes
+	}
+	return result
+}
+
+func New() *UUID {
+	var bytes [16]byte
+	rand.Read(bytes[:])
+	return &UUID{
+		byteValue:   bytes,
+		stringValue: bytesToString(bytes),
+	}
+}
+
+func ParseString(str string) (*UUID, error) {
+	text := []byte(str)
+	if len(text) < 32 {
+		return nil, InvalidID
+	}
+
+	var uuid UUID
+	uuid.stringValue = str
+	b := uuid.byteValue[:]
+
+	for _, byteGroup := range byteGroups {
+		if text[0] == '-' {
+			text = text[1:]
+		}
+
+		_, err := hex.Decode(b[:byteGroup/2], text[:byteGroup])
+
+		if err != nil {
+			return nil, err
+		}
+
+		text = text[byteGroup:]
+		b = b[byteGroup/2:]
+	}
+
+	return &uuid, nil
+}