generated from PenaSide/GolangTemplate
34 lines
874 B
Go
34 lines
874 B
Go
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package utils
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import (
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"math/rand"
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"time"
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)
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const (
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letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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letterIndexBits = 6 // 6 bits to represent a letter index
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letterIndexMask = 1<<letterIndexBits - 1 // All 1-bits, as many as letterIdxBits
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letterIndexMax = 63 / letterIndexBits // # of letter indices fitting in 63 bits
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)
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func GetRandomString(size int) string {
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src := rand.NewSource(time.Now().UnixNano())
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bytes := make([]byte, size)
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for bytesIndex, cache, remain := size-1, src.Int63(), letterIndexMax; bytesIndex >= 0; {
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if remain == 0 {
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cache, remain = src.Int63(), letterIndexMax
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}
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if letterIndex := int(cache & letterIndexMask); letterIndex < len(letterBytes) {
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bytes[bytesIndex] = letterBytes[letterIndex]
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bytesIndex--
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}
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cache >>= letterIndexBits
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remain--
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}
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return string(bytes)
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}
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