init repo

vendor/github.com/alibabacloud-go/tea-utils/service/util.go

@@ -0,0 +1,52 @@
+package service
+
+import (
+	"crypto/md5"
+	"crypto/rand"
+	"encoding/hex"
+	"hash"
+	rand2 "math/rand"
+)
+
+type UUID [16]byte
+
+const numBytes = "1234567890"
+
+func getUUID() (uuidHex string) {
+	uuid := newUUID()
+	uuidHex = hex.EncodeToString(uuid[:])
+	return
+}
+
+func randStringBytes(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = numBytes[rand2.Intn(len(numBytes))]
+	}
+	return string(b)
+}
+
+func newUUID() UUID {
+	ns := UUID{}
+	safeRandom(ns[:])
+	u := newFromHash(md5.New(), ns, randStringBytes(16))
+	u[6] = (u[6] & 0x0f) | (byte(2) << 4)
+	u[8] = (u[8]&(0xff>>2) | (0x02 << 6))
+
+	return u
+}
+
+func newFromHash(h hash.Hash, ns UUID, name string) UUID {
+	u := UUID{}
+	h.Write(ns[:])
+	h.Write([]byte(name))
+	copy(u[:], h.Sum(nil))
+
+	return u
+}
+
+func safeRandom(dest []byte) {
+	if _, err := rand.Read(dest); err != nil {
+		panic(err)
+	}
+}