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unstable.go
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unstable.go
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package mathx
import (
"math/rand"
"sync"
"time"
)
// A Unstable is used to generate random value around the mean value base on given deviation.
type Unstable struct {
deviation float64
r *rand.Rand
lock *sync.Mutex
}
// NewUnstable returns a Unstable.
func NewUnstable(deviation float64) Unstable {
if deviation < 0 {
deviation = 0
}
if deviation > 1 {
deviation = 1
}
return Unstable{
deviation: deviation,
r: rand.New(rand.NewSource(time.Now().UnixNano())),
lock: new(sync.Mutex),
}
}
// AroundDuration returns a random duration with given base and deviation.
func (u Unstable) AroundDuration(base time.Duration) time.Duration {
u.lock.Lock()
val := time.Duration((1 + u.deviation - 2*u.deviation*u.r.Float64()) * float64(base))
u.lock.Unlock()
return val
}
// AroundInt returns a random int64 with given base and deviation.
func (u Unstable) AroundInt(base int64) int64 {
u.lock.Lock()
val := int64((1 + u.deviation - 2*u.deviation*u.r.Float64()) * float64(base))
u.lock.Unlock()
return val
}