52 lines
792 B
Go
52 lines
792 B
Go
package lib
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import (
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crand "crypto/rand"
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"math"
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"math/big"
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"math/rand"
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"sync"
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log "github.com/sirupsen/logrus"
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)
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var (
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once sync.Once
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)
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// SeedMathRand Credit: https://github.com/hashicorp/consul/blob/main/lib/rand.go
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func SeedMathRand() error {
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var (
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n *big.Int
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err error
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)
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once.Do(func() {
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n, err = crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
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if err != nil {
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log.Errorf("cannot seed math/rand: %s", err)
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} else {
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log.Debugf("seeding math/rand %+v", n.Int64())
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rand.Seed(n.Int64())
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}
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})
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return err
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}
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func RandInt(min int, max int) int {
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return rand.Intn(max-min+1) + min
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}
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func MapRand[K comparable, V any](m map[K]V) V {
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n := rand.Intn(len(m))
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i := 0
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for _, v := range m {
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if i == n {
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return v
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}
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i++
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}
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panic("unreachable")
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}
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