50 lines
1.1 KiB
Go
50 lines
1.1 KiB
Go
package utils
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import (
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tRand "crypto/rand"
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"math/big"
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"math/rand"
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"time"
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)
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var defaultLetters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
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// GetPseudoRandomCode 伪随机数（性能高）
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func GetPseudoRandomCode(n int, allowedChars ...[]rune) string {
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//rand.Seed(time.Now().UnixNano())
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rand.New(rand.NewSource(time.Now().UnixNano()))
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var letters []rune
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if len(allowedChars) == 0 {
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letters = defaultLetters
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} else {
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letters = allowedChars[0]
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}
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b := make([]rune, n)
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for i := range b {
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b[i] = letters[rand.Intn(len(letters))]
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}
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return string(b)
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}
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// GetTrueRandomCode 真随机数 （在linux上已经有一个实现就是/dev/urandom，crypto/rand 就是从这个地方读“真随机”数字返回，但性能比较慢）
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func GetTrueRandomCode(n int, allowedChars ...[]rune) string {
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var letters []rune
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if len(allowedChars) == 0 {
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letters = defaultLetters
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} else {
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letters = allowedChars[0]
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}
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b := make([]rune, n)
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for i := range b {
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n, _ := tRand.Int(tRand.Reader, big.NewInt(int64(len(letters))))
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b[i] = letters[n.Int64()]
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}
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return string(b)
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}
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