sliding_window_counter

Documentation

Overview

Package fixed_window_counter provides a rate limiter implemented by sliding window counter algorithm.

Index

• Constants
• type Limit
• type RateLimiter
  • func NewRateLimiter(client *redis.Client, limit Limit, actionKey string, period time.Duration, ...) *RateLimiter
  • func (limiter *RateLimiter) Allow(ctx context.Context) bool
  • func (limiter *RateLimiter) Wait(ctx context.Context) bool

Constants

const Inf = Limit(math.MaxInt64)

Inf is the infinite rate limit; it allows all events.

Types

type Limit

type Limit int64

Limit defines the maximum frequency of some events. Limit is represented as number of events per second. A zero Limit allows no events.

type RateLimiter

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

RateLimiter controls how frequently events are allowed to happen. The zero value is a valid Limiter, but it will reject all events.

RateLimiter has two main method: Allow and Wait

If the count of actionKey is greater or equal to the limit in a period time, Allow returns false

If the count of actionKey is greater or equal to the limit in a period time, Wait blocks until the count of actionKey is less than the limit or its associated context.Context is canceled.

func NewRateLimiter

func NewRateLimiter(client *redis.Client, limit Limit, actionKey string, period time.Duration,
	interval time.Duration) *RateLimiter

NewRateLimiter returns a new RateLimiter that allows the action up to happening limit times in a period time.

func (*RateLimiter) Allow

func (limiter *RateLimiter) Allow(ctx context.Context) bool

Allow reports whether the action exceed the rate limit. Use this method if you intend to drop / skip action that exceed the rate limit. Otherwise use Wait.

func (*RateLimiter) Wait

func (limiter *RateLimiter) Wait(ctx context.Context) bool

Wait reports whether the action exceed the rate limit.