ratelimit

README

RateLimit

Simple, thread-safe Go rate-limiter. Inspired by Antti Huima's algorithm on http://stackoverflow.com/a/668327

Example

package main

import (
  "github.com/bsm/ratelimit"
  "log"
)

func main() {
  // Create a new rate-limiter, allowing up-to 10 calls
  // per second
  rl := ratelimit.New(10, time.Second)

  for i:=0; i<20; i++ {
    if rl.Limit() {
      fmt.Println("DOH! Over limit!")
    } else {
      fmt.Println("OK")
    }
  }
}

Licence

Copyright (c) 2015 Black Square Media

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Documentation

Overview

Simple, thread-safe Go rate-limiter. Inspired by Antti Huima's algorithm on http://stackoverflow.com/a/668327

Example:

// Create a new rate-limiter, allowing up-to 10 calls
// per second
rl := ratelimit.New(10, time.Second)

for i:=0; i<20; i++ {
  if rl.Limit() {
    fmt.Println("DOH! Over limit!")
  } else {
    fmt.Println("OK")
  }
}

Index

• type RateLimiter
  • func New(rate int, per time.Duration) *RateLimiter
  • func (rl *RateLimiter) Limit() bool
  • func (rl *RateLimiter) Undo()
  • func (rl *RateLimiter) UpdateRate(rate int)

Types

type RateLimiter

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

RateLimiter instances are thread-safe.

func New

func New(rate int, per time.Duration) *RateLimiter

New creates a new rate limiter instance

func (*RateLimiter) Limit

func (rl *RateLimiter) Limit() bool

Limit returns true if rate was exceeded

func (*RateLimiter) Undo

func (rl *RateLimiter) Undo()

Undo reverts the last Limit() call, returning consumed allowance

func (*RateLimiter) UpdateRate

func (rl *RateLimiter) UpdateRate(rate int)

UpdateRate allows to update the allowed rate