shapeio

README

shapeio

Traffic shaper for Golang io.Reader and io.Writer

https://github.com/fujiwara/shapeio

import "github.com/fujiwara/shapeio"

func ExampleReader() {
	// example for downloading http body with rate limit.
	resp, _ := http.Get("http://example.com")
	defer resp.Body.Close()

	reader := shapeio.NewReader(resp.Body)
	reader.SetRateLimit(1024 * 10) // 10KB/sec
	io.Copy(ioutil.Discard, reader)
}

func ExampleWriter() {
	// example for writing file with rate limit.
	src := bytes.NewReader(bytes.Repeat([]byte{0}, 32*1024)) // 32KB
	f, _ := os.Create("/tmp/foo")
	writer := shapeio.NewWriter(f)
	writer.SetRateLimit(1024 * 10) // 10KB/sec
	io.Copy(writer, src)
	f.Close()
}

Usage

type Reader

type Reader struct {
}

func NewReader

func NewReader(r io.Reader) *Reader

NewReader returns a reader that implements io.Reader with rate limiting.

func (*Reader) Read

func (s *Reader) Read(p []byte) (int, error)

Read reads bytes into p.

func (*Reader) SetRateLimit

func (s *Reader) SetRateLimit(l float64)

SetRateLimit sets rate limit (bytes/sec) to the reader.

type Writer

type Writer struct {
}

func NewWriter

func NewWriter(w io.Writer) *Writer

NewWriter returns a writer that implements io.Writer with rate limiting.

func (*Writer) SetRateLimit

func (s *Writer) SetRateLimit(l float64)

SetRateLimit sets rate limit (bytes/sec) to the writer.

func (*Writer) Write

func (s *Writer) Write(p []byte) (int, error)

Write writes bytes from p.

License

The MIT License (MIT)

Copyright (c) 2016 FUJIWARA Shunichiro

Documentation

Index

• func NewRateLimiterSetter(w RateLimiterSetter, fns ...LimitConfigFn)
• func WrapReadCloser(r io.Reader) io.ReadCloser
• func WrapWriteCloser(r io.Writer) io.WriteCloser
• type LimitConfig
• type LimitConfigFn
  • func WithContext(ctx context.Context) LimitConfigFn
  • func WithRateLimit(rateLimit float64) LimitConfigFn
• type RateLimiter
  • func NewRateLimiter(fns ...LimitConfigFn) *RateLimiter
  • func (s *RateLimiter) SetContext(ctx context.Context)
  • func (s *RateLimiter) SetRateLimit(bytesPerSec float64)
• type RateLimiterSetter
• type Reader
  • func NewReader(r io.Reader, fns ...LimitConfigFn) *Reader
  • func (s *Reader) Read(p []byte) (int, error)
• type Writer
  • func NewWriter(w io.Writer, fns ...LimitConfigFn) *Writer
  • func (s *Writer) Write(p []byte) (int, error)

Examples

• Reader
• Writer

Functions

func NewRateLimiterSetter

func NewRateLimiterSetter(w RateLimiterSetter, fns ...LimitConfigFn)

func WrapReadCloser

func WrapReadCloser(r io.Reader) io.ReadCloser

WrapReadCloser returns a ReadCloser with Close method wrapping the provided Reader r.

func WrapWriteCloser

func WrapWriteCloser(r io.Writer) io.WriteCloser

WrapWriteCloser returns a WriteCloser with Close method wrapping the provided Writer r.

Types

type LimitConfig

type LimitConfig struct {
	context.Context
	RateLimit float64
}

type LimitConfigFn

type LimitConfigFn func(*LimitConfig)

func WithContext

func WithContext(ctx context.Context) LimitConfigFn

func WithRateLimit

func WithRateLimit(rateLimit float64) LimitConfigFn

type RateLimiter

type RateLimiter struct {
	*rate.Limiter
	context.Context
}

func NewRateLimiter

func NewRateLimiter(fns ...LimitConfigFn) *RateLimiter

func (*RateLimiter) SetContext

func (s *RateLimiter) SetContext(ctx context.Context)

func (*RateLimiter) SetRateLimit

func (s *RateLimiter) SetRateLimit(bytesPerSec float64)

SetRateLimit sets rate limit (bytes/sec) to the reader.

type RateLimiterSetter

type RateLimiterSetter interface {
	SetContext(ctx context.Context)
	SetRateLimit(bytesPerSec float64)
}

type Reader

type Reader struct {
	io.ReadCloser
	RateLimiter
}

Example

package main

import (
	"io"
	"io/ioutil"
	"net/http"

	"github.com/bingoohuang/ngg/goup/shapeio"
)

func main() {
	// example for downloading http body with rate limit.
	resp, _ := http.Get("http://example.com")
	defer resp.Body.Close()

	reader := shapeio.NewReader(resp.Body)
	reader.SetRateLimit(1024 * 10) // 10KB/sec
	io.Copy(ioutil.Discard, reader)
}

func NewReader

func NewReader(r io.Reader, fns ...LimitConfigFn) *Reader

NewReader returns a reader that implements io.Reader with rate limiting.

func (*Reader) Read

func (s *Reader) Read(p []byte) (int, error)

Read reads bytes into p.

type Writer

type Writer struct {
	io.WriteCloser
	RateLimiter
}

Example

package main

import (
	"bytes"
	"io"
	"os"

	"github.com/bingoohuang/ngg/goup/shapeio"
)

func main() {
	// example for writing file with rate limit.
	src := bytes.NewReader(bytes.Repeat([]byte{0}, 32*1024)) // 32KB
	f, _ := os.Create("/tmp/foo")
	writer := shapeio.NewWriter(f)
	writer.SetRateLimit(1024 * 10) // 10KB/sec
	io.Copy(writer, src)
	f.Close()
}

func NewWriter

func NewWriter(w io.Writer, fns ...LimitConfigFn) *Writer

NewWriter returns a writer that implements io.Writer with rate limiting.

func (*Writer) Write

func (s *Writer) Write(p []byte) (int, error)

Write writes bytes from p.