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51 lines
999 B
Go
51 lines
999 B
Go
package random
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import (
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"math/rand"
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"strings"
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"sync"
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"time"
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)
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var r *rand.Rand
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var mu sync.Mutex
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func init() {
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r = rand.New(rand.NewSource(time.Now().UnixNano()))
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}
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// String returns a random string of 20 characters
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func String() string {
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mu.Lock()
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defer mu.Unlock()
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var output strings.Builder
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chars := "abcdedfghijklmnopqrstABCDEFGHIJKLMNOP"
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for i := 0; i < 20; i++ {
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random := r.Intn(len(chars))
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randomChar := chars[random]
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output.WriteString(string(randomChar))
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}
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return output.String()
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}
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// Float64 returns a random float64
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func Float64() float64 {
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mu.Lock()
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defer mu.Unlock()
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return r.Float64()
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}
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// Intn returns a random int
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func Intn(n int) int {
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mu.Lock()
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defer mu.Unlock()
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return r.Intn(n)
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}
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// Jitter adds a little bit of randomness to a given duration. This is
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// useful to prevent nodes across the cluster performing certain operations
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// all at the same time.
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func Jitter(d time.Duration) time.Duration {
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return d + time.Duration(Float64()*float64(d))
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}
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