2b9301cd47
cascade-kinesis-client will be used as a submodule of other projects, so it should not have "src/vmware.com/cascade-kinesis-client" in its path. To build this project locally, please manually create the parent folders. Change-Id: I8844e6a0e32aae65b28496915d8507e9fb1058c6
30 lines
806 B
Go
30 lines
806 B
Go
package utils
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import (
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"math/rand"
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)
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const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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const (
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letterIdxBits = 6 // 6 bits to represent a letter index
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letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
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letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
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)
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func RandStringBytesMaskImpr(n int) string {
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b := make([]byte, n)
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// A rand.Int63() generates 63 random bits, enough for letterIdxMax letters!
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for i, cache, remain := n-1, rand.Int63(), letterIdxMax; i >= 0; {
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if remain == 0 {
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cache, remain = rand.Int63(), letterIdxMax
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}
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if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
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b[i] = letterBytes[idx]
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i--
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}
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cache >>= letterIdxBits
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remain--
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}
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return string(b)
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}
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