ratelimit

README

ratelimit

Adaptive rate limit, only available for linux systems.

Example of use

gin ratelimit middleware

import (
rl "github.com/zhufuyi/sponge/pkg/shield/ratelimit"
)

func RateLimit(opts ...RateLimitOption) gin.HandlerFunc {
	o := defaultRatelimitOptions()
	o.apply(opts...)
	limiter := rl.NewLimiter(
		rl.WithWindow(o.window),
		rl.WithBucket(o.bucket),
		rl.WithCPUThreshold(o.cpuThreshold),
		rl.WithCPUQuota(o.cpuQuota),
	)

	return func(c *gin.Context) {
		done, err := limiter.Allow()
		if err != nil {
			response.Output(c, http.StatusTooManyRequests, err.Error())
			c.Abort()
			return
		}

		c.Next()

		done(rl.DoneInfo{Err: c.Request.Context().Err()})
	}
}

grpc ratelimit interceptor

import (
	rl "github.com/zhufuyi/sponge/pkg/shield/ratelimit"
)


func UnaryServerRateLimit(opts ...RatelimitOption) grpc.UnaryServerInterceptor {
	o := defaultRatelimitOptions()
	o.apply(opts...)
	limiter := rl.NewLimiter(
		rl.WithWindow(o.window),
		rl.WithBucket(o.bucket),
		rl.WithCPUThreshold(o.cpuThreshold),
		rl.WithCPUQuota(o.cpuQuota),
	)

	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
		done, err := limiter.Allow()
		if err != nil {
			return nil, errcode.StatusLimitExceed.ToRPCErr(err.Error())
		}

		reply, err := handler(ctx, req)
		done(rl.DoneInfo{Err: err})
		return reply, err
	}
}

Documentation

Overview

Package ratelimit is an adaptive rate limit library, support for use in gin middleware and grpc interceptors.

Index

• Variables
• type BBR
  • func NewLimiter(opts ...Option) *BBR
  • func (l *BBR) Allow() (DoneFunc, error)
  • func (l *BBR) Stat() Stat
• type DoneFunc
• type DoneInfo
• type Limiter
• type Option
  • func WithBucket(b int) Option
  • func WithCPUQuota(quota float64) Option
  • func WithCPUThreshold(threshold int64) Option
  • func WithWindow(d time.Duration) Option
• type Stat

Variables

var (
	// ErrLimitExceed is returned when the rate limiter is
	// triggered and the request is rejected due to limit exceeded.
	ErrLimitExceed = errors.New("rate limit exceeded")
)

Types

type BBR

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

BBR implements bbr-like limiter. It is inspired by sentinel. https://github.com/alibaba/Sentinel/wiki/%E7%B3%BB%E7%BB%9F%E8%87%AA%E9%80%82%E5%BA%94%E9%99%90%E6%B5%81

func NewLimiter

func NewLimiter(opts ...Option) *BBR

NewLimiter returns a bbr limiter

func (*BBR) Allow

func (l *BBR) Allow() (DoneFunc, error)

Allow checks all inbound traffic. Once overload is detected, it raises limit.ErrLimitExceed error.

func (*BBR) Stat

func (l *BBR) Stat() Stat

Stat tasks a snapshot of the bbr limiter.

type DoneFunc

type DoneFunc func(DoneInfo)

DoneFunc is done function.

type DoneInfo

type DoneInfo struct {
	Err error
}

DoneInfo is done info.

type Limiter

type Limiter interface {
	Allow() (DoneFunc, error)
}

Limiter is a rate limiter.

type Option

type Option func(*options)

Option function for bbr limiter

func WithBucket

func WithBucket(b int) Option

WithBucket with bucket ize.

func WithCPUQuota

func WithCPUQuota(quota float64) Option

WithCPUQuota with real cpu quota(if it can not collect from process correct);

func WithCPUThreshold

func WithCPUThreshold(threshold int64) Option

WithCPUThreshold with cpu threshold;

func WithWindow

func WithWindow(d time.Duration) Option

WithWindow with window size.

type Stat

type Stat struct {
	CPU         int64
	InFlight    int64
	MaxInFlight int64
	MinRt       int64
	MaxPass     int64
}

Stat contains the metrics snapshot of bbr.