limit

Documentation

Index

• Constants
• Variables
• type PeriodLimit
  • func NewPeriodLimit(period, quota int, limitStore *redis.Redis, keyPrefix string, ...) *PeriodLimit
  • func (h *PeriodLimit) Take(key string) (int, error)
  • func (h *PeriodLimit) TakeCtx(ctx context.Context, key string) (int, error)
• type PeriodOption
  • func Align() PeriodOption
• type TokenLimiter
  • func NewTokenLimiter(rate, burst int, store *redis.Redis, key string) *TokenLimiter
  • func (lim *TokenLimiter) Allow() bool
  • func (lim *TokenLimiter) AllowCtx(ctx context.Context) bool
  • func (lim *TokenLimiter) AllowN(now time.Time, n int) bool
  • func (lim *TokenLimiter) AllowNCtx(ctx context.Context, now time.Time, n int) bool

Constants

const (
	// Unknown means not initialized state.
	Unknown = iota
	// Allowed means allowed state.
	Allowed
	// HitQuota means this request exactly hit the quota.
	HitQuota
	// OverQuota means passed the quota.
	OverQuota
)

Variables

var ErrUnknownCode = errors.New("unknown status code")

ErrUnknownCode is an error that represents unknown status code.

Types

type PeriodLimit

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

A PeriodLimit is used to limit requests during a period of time.

func NewPeriodLimit

func NewPeriodLimit(period, quota int, limitStore *redis.Redis, keyPrefix string,
	opts ...PeriodOption) *PeriodLimit

NewPeriodLimit returns a PeriodLimit with given parameters.

func (*PeriodLimit) Take

func (h *PeriodLimit) Take(key string) (int, error)

Take requests a permit, it returns the permit state.

func (*PeriodLimit) TakeCtx

func (h *PeriodLimit) TakeCtx(ctx context.Context, key string) (int, error)

TakeCtx requests a permit with context, it returns the permit state.

type PeriodOption

type PeriodOption func(l *PeriodLimit)

PeriodOption defines the method to customize a PeriodLimit.

func Align

func Align() PeriodOption

Align returns a func to customize a PeriodLimit with alignment. For example, if we want to limit end users with 5 sms verification messages every day, we need to align with the local timezone and the start of the day.

type TokenLimiter

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

A TokenLimiter controls how frequently events are allowed to happen with in one second.

func NewTokenLimiter

func NewTokenLimiter(rate, burst int, store *redis.Redis, key string) *TokenLimiter

NewTokenLimiter returns a new TokenLimiter that allows events up to rate and permits bursts of at most burst tokens.

func (*TokenLimiter) Allow

func (lim *TokenLimiter) Allow() bool

Allow is shorthand for AllowN(time.Now(), 1).

func (*TokenLimiter) AllowCtx

func (lim *TokenLimiter) AllowCtx(ctx context.Context) bool

AllowCtx is shorthand for AllowNCtx(ctx,time.Now(), 1) with incoming context.

func (*TokenLimiter) AllowN

func (lim *TokenLimiter) AllowN(now time.Time, n int) bool

AllowN reports whether n events may happen at time now. Use this method if you intend to drop / skip events that exceed the rate. Otherwise, use Reserve or Wait.

func (*TokenLimiter) AllowNCtx

func (lim *TokenLimiter) AllowNCtx(ctx context.Context, now time.Time, n int) bool

AllowNCtx reports whether n events may happen at time now with incoming context. Use this method if you intend to drop / skip events that exceed the rate. Otherwise, use Reserve or Wait.