random

type Backoff interface {
	// NextBackOff provides the duration expected to wait before retrying an
	// action. time.Duration = -1 indicates that no more retry should be
	// attempted.
	NextBackOff() time.Duration
	// Reset sets the backoff back to its initial state.
	Reset()
}

type Service interface {
	// CreateMax tries to create one new pseudo random number. The generated
	// number is within the range [0 max), which means that max is exclusive.
	CreateMax(max int) (int, error)
	// CreateNMax tries to create a list of new pseudo random numbers. n
	// represents the number of pseudo random numbers in the returned list. The
	// generated numbers are within the range [0 max), which means that max is
	// exclusive.
	CreateNMax(n, max int) ([]int, error)
}

type ServiceConfig struct {

	// BackoffFactory is supposed to be able to create a new spec.Backoff. Retry
	// implementations can make use of this to decide when to retry.
	BackoffFactory func() Backoff
	// RandFactory represents a service returning random values. Here e.g.
	// crypto/rand.Int can be used.
	RandFactory func(rand io.Reader, max *big.Int) (n *big.Int, err error)

	// RandReader represents an instance of a cryptographically strong
	// pseudo-random generator. Here e.g. crypto/rand.Reader can be used.
	RandReader io.Reader
	// Timeout represents the deadline being waited during random number creation
	// before returning a timeout error.
	Timeout time.Duration
}