replace zxq.co/ripple/hanayo

vendor/zxq.co/ripple/rippleapi/common/random_string.go

@@ -0,0 +1,33 @@
+package common
+
+import (
+	"math/rand"
+	"time"
+)
+
+const letterBytes = "0123456789abcdef"
+const (
+	letterIdxBits = 6                    // 6 bits to represent a letter index
+	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
+	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
+)
+
+var randSrc = rand.NewSource(time.Now().UnixNano())
+
+// RandomString generates a random string.
+func RandomString(n int) string {
+	b := make([]byte, n)
+	// A randSrc.Int63() generates 63 random bits, enough for letterIdxMax characters!
+	for i, cache, remain := n-1, randSrc.Int63(), letterIdxMax; i >= 0; {
+		if remain == 0 {
+			cache, remain = randSrc.Int63(), letterIdxMax
+		}
+		if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
+			b[i] = letterBytes[idx]
+			i--
+		}
+		cache >>= letterIdxBits
+		remain--
+	}
+	return string(b)
+}