add vendor

vendor/github.com/astaxie/beego/utils/rand.go

@@ -0,0 +1,44 @@
+// Copyright 2014 beego Author. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+	"crypto/rand"
+	r "math/rand"
+	"time"
+)
+
+var alphaNum = []byte(`0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`)
+
+// RandomCreateBytes generate random []byte by specify chars.
+func RandomCreateBytes(n int, alphabets ...byte) []byte {
+	if len(alphabets) == 0 {
+		alphabets = alphaNum
+	}
+	var bytes = make([]byte, n)
+	var randBy bool
+	if num, err := rand.Read(bytes); num != n || err != nil {
+		r.Seed(time.Now().UnixNano())
+		randBy = true
+	}
+	for i, b := range bytes {
+		if randBy {
+			bytes[i] = alphabets[r.Intn(len(alphabets))]
+		} else {
+			bytes[i] = alphabets[b%byte(len(alphabets))]
+		}
+	}
+	return bytes
+}