go.etcd.io/etcd@v3.3.27+incompatible/pkg/stringutil/stringutil.go (about)

     1  // Copyright 2016 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package stringutil exports string utility functions.
    16  package stringutil
    17  
    18  import "math/rand"
    19  
    20  const (
    21  	chars = "abcdefghijklmnopqrstuvwxyz0123456789"
    22  )
    23  
    24  // UniqueStrings returns a slice of randomly generated unique strings.
    25  func UniqueStrings(maxlen uint, n int) []string {
    26  	exist := make(map[string]bool)
    27  	ss := make([]string, 0)
    28  
    29  	for len(ss) < n {
    30  		s := randomString(maxlen)
    31  		if !exist[s] {
    32  			exist[s] = true
    33  			ss = append(ss, s)
    34  		}
    35  	}
    36  
    37  	return ss
    38  }
    39  
    40  // RandomStrings returns a slice of randomly generated strings.
    41  func RandomStrings(maxlen uint, n int) []string {
    42  	ss := make([]string, 0)
    43  	for i := 0; i < n; i++ {
    44  		ss = append(ss, randomString(maxlen))
    45  	}
    46  	return ss
    47  }
    48  
    49  func randomString(l uint) string {
    50  	s := make([]byte, l)
    51  	for i := 0; i < int(l); i++ {
    52  		s[i] = chars[rand.Intn(len(chars))]
    53  	}
    54  	return string(s)
    55  }