mirror of
https://github.com/duke-git/lancet.git
synced 2026-02-04 21:02:27 +08:00
141 lines
3.2 KiB
Go
141 lines
3.2 KiB
Go
// Copyright 2021 dudaodong@gmail.com. All rights reserved.
|
|
// Use of this source code is governed by MIT license.
|
|
|
|
// Package random implements some basic functions to generate random int and string.
|
|
package random
|
|
|
|
import (
|
|
crand "crypto/rand"
|
|
"fmt"
|
|
"io"
|
|
"math/rand"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
Numeral = "0123456789"
|
|
LowwerLetters = "abcdefghijklmnopqrstuvwxyz"
|
|
UpperLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
Letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
)
|
|
|
|
func init() {
|
|
rand.Seed(time.Now().UnixNano())
|
|
}
|
|
|
|
// RandInt generate random int between min and max, maybe min, not be max.
|
|
// Play: https://go.dev/play/p/pXyyAAI5YxD
|
|
func RandInt(min, max int) int {
|
|
if min == max {
|
|
return min
|
|
}
|
|
if max < min {
|
|
min, max = max, min
|
|
}
|
|
|
|
// fix: https://github.com/duke-git/lancet/issues/75
|
|
// r := rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
// return r.Intn(max-min) + min
|
|
|
|
return rand.Intn(max-min) + min
|
|
}
|
|
|
|
// RandBytes generate random byte slice.
|
|
// Play: https://go.dev/play/p/EkiLESeXf8d
|
|
func RandBytes(length int) []byte {
|
|
if length < 1 {
|
|
return []byte{}
|
|
}
|
|
b := make([]byte, length)
|
|
|
|
if _, err := io.ReadFull(crand.Reader, b); err != nil {
|
|
return nil
|
|
}
|
|
|
|
return b
|
|
}
|
|
|
|
// RandString generate random string of specified length.
|
|
// Play: https://go.dev/play/p/W2xvRUXA7Mi
|
|
func RandString(length int) string {
|
|
return random(Letters, length)
|
|
}
|
|
|
|
// RandUpper generate a random upper case string.
|
|
// Play: https://go.dev/play/p/29QfOh0DVuh
|
|
func RandUpper(length int) string {
|
|
return random(UpperLetters, length)
|
|
}
|
|
|
|
// RandLower generate a random lower case string.
|
|
// Play: https://go.dev/play/p/XJtZ471cmtI
|
|
func RandLower(length int) string {
|
|
return random(LowwerLetters, length)
|
|
}
|
|
|
|
// RandNumeral generate a random numeral string of specified length.
|
|
// Play: https://go.dev/play/p/g4JWVpHsJcf
|
|
func RandNumeral(length int) string {
|
|
return random(Numeral, length)
|
|
}
|
|
|
|
// RandNumeralOrLetter generate a random numeral or letter string.
|
|
// Play: https://go.dev/play/p/19CEQvpx2jD
|
|
func RandNumeralOrLetter(length int) string {
|
|
return random(Numeral+Letters, length)
|
|
}
|
|
|
|
// random generate a random string based on given string range.
|
|
func random(s string, length int) string {
|
|
b := make([]byte, length)
|
|
|
|
// fix: https://github.com/duke-git/lancet/issues/75
|
|
// r := rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
|
|
for i := range b {
|
|
b[i] = s[rand.Int63()%int64(len(s))]
|
|
}
|
|
|
|
return string(b)
|
|
}
|
|
|
|
// UUIdV4 generate a random UUID of version 4 according to RFC 4122.
|
|
// Play: https://go.dev/play/p/_Z9SFmr28ft
|
|
func UUIdV4() (string, error) {
|
|
uuid := make([]byte, 16)
|
|
|
|
n, err := io.ReadFull(crand.Reader, uuid)
|
|
if n != len(uuid) || err != nil {
|
|
return "", err
|
|
}
|
|
|
|
uuid[8] = uuid[8]&^0xc0 | 0x80
|
|
uuid[6] = uuid[6]&^0xf0 | 0x40
|
|
|
|
return fmt.Sprintf("%x-%x-%x-%x-%x", uuid[0:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:]), nil
|
|
}
|
|
|
|
// RandUniqueIntSlice generate a slice of random int of length n that do not repeat
|
|
func RandUniqueIntSlice(n, min, max int) []int {
|
|
if min > max {
|
|
return []int{}
|
|
}
|
|
if n > max-min {
|
|
n = max - min
|
|
}
|
|
|
|
nums := make([]int, n)
|
|
used := make(map[int]struct{}, n)
|
|
for i := 0; i < n; {
|
|
r := RandInt(min, max)
|
|
if _, use := used[r]; use {
|
|
continue
|
|
}
|
|
used[r] = struct{}{}
|
|
nums[i] = r
|
|
i++
|
|
}
|
|
|
|
return nums
|
|
}
|