package randutil

import "go.mongodb.org/mongo-driver/internal/randutil"

Package randutil provides common random number utilities.

Index ¶

• func CryptoSeed() int64
• type LockedRand
• func NewLockedRand(src rand.Source) *LockedRand
• func (lr *LockedRand) Intn(n int) int
• func (lr *LockedRand) Read(p []byte) (int, error)
• func (lr *LockedRand) Shuffle(n int, swap func(i, j int))

Functions ¶

func CryptoSeed ¶

func CryptoSeed() int64

CryptoSeed returns a random int64 read from the "crypto/rand" random number generator. It is intended to be used to seed pseudorandom number generators at package initialization. It panics if it encounters any errors.

Types ¶

type LockedRand ¶

type LockedRand struct {
	// contains filtered or unexported fields
}

A LockedRand wraps a "math/rand".Rand and is safe to use from multiple goroutines.

func NewLockedRand ¶

func NewLockedRand(src rand.Source) *LockedRand

NewLockedRand returns a new LockedRand that uses random values from src to generate other random values. It is safe to use from multiple goroutines.

func (*LockedRand) Intn ¶

func (lr *LockedRand) Intn(n int) int

Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n <= 0.

func (*LockedRand) Read ¶

func (lr *LockedRand) Read(p []byte) (int, error)

Read generates len(p) random bytes and writes them into p. It always returns len(p) and a nil error.

func (*LockedRand) Shuffle ¶

func (lr *LockedRand) Shuffle(n int, swap func(i, j int))

Shuffle pseudo-randomizes the order of elements. n is the number of elements. Shuffle panics if n < 0. swap swaps the elements with indexes i and j.

Note that Shuffle locks the LockedRand, so shuffling large collections may adversely affect other concurrent calls. If many concurrent Shuffle and random value calls are required, consider using the global "math/rand".Shuffle instead because it uses much more granular locking.

Source Files ¶

randutil.go