.godocdown.md

Limio is meant to be a dead simple rate-limiting library, primarily aimed at providing an intuitive API surface for composable operational constraints. By centering around chan int, limio provides token bucket implementations with decent backpressure and helps eliminate silly window syndrome by spreading out token distribution over smaller units of time to provide a more even flow.

By using a channel, we also eliminate the need of Limiter implementations to follow a complex contract involving rates. They simply need to listen on a channel for some quantity, and then when a quantity arrives, perform that many operations.

Some examples usage of the limio.Reader

func slowCopy(w io.Writer, r io.Reader) error {
  lr := limio.NewReader(r)

  // Limit at 1MB/s
  lr.SimpleLimit(1*KB, time.Second)

  _, err := io.Copy(w, lr)
  return err
}

func slowGroupCopy(ws []io.Writer, rs []io.Reader) error {
  // For a simpler example, imagine len(ws) == len(rs) always

  lmr := limio.NewSimpleManager()
  // Limit all operations to an aggregate 1MB/s
  lmr.SimpleLimit(1*MB, time.Second)

  wg := &sync.WaitGroup{}
  wg.Add(len(ws))

  for i := range ws {
    go func(i int) {
      lr := limio.NewReader(rs[i])
      lmr.Manage(lr)

      // Obviously handle the errors in a real implementation
      io.Copy(ws[i], lr)
      wg.Done()
    }(i)
  }

  wg.Wait()
  return nil
}

Docs

{{ .Emit }}