https://github.com/cevatbarisyilmaz/lossy

Go package to simulate bandwidth, latency and packet loss for net.PacketConn and net.Conn interfaces
https://github.com/cevatbarisyilmaz/lossy

go golang latency lossy packet-loss udp

Last synced: 14 days ago
JSON representation

Go package to simulate bandwidth, latency and packet loss for net.PacketConn and net.Conn interfaces

• Host: GitHub
• URL: https://github.com/cevatbarisyilmaz/lossy
• Owner: cevatbarisyilmaz
• License: mit
• Created: 2019-08-21T13:46:06.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2019-10-05T12:22:12.000Z (over 4 years ago)
• Last Synced: 2024-02-19T16:36:33.155Z (4 months ago)
• Topics: go, golang, latency, lossy, packet-loss, udp
• Language: Go
• Homepage:
• Size: 19.5 KB
• Stars: 316
• Watchers: 5
• Forks: 9
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• my-awesome-stars - lossy
• go-awesome - lossy - 模拟 net.PacketConn 和 net.Conn 接口的带宽，延迟和数据包丢失 (开源类库 / 网络)
• go-awesome - lossy - simulates bandwidth, latency and packet loss for net.PacketConn and net.Conn interfaces (Open source library / The Internet)
• go-awesome - lossy - 模拟 net.PacketConn 和 net.Conn 接口的带宽，延迟和数据包丢失 (开源类库 / 网络)
• awesome-stars - cevatbarisyilmaz/lossy - Go package to simulate bandwidth, latency and packet loss for net.PacketConn and net.Conn interfaces (golang)

README

        
# lossy

[![GoDoc](https://godoc.org/github.com/cevatbarisyilmaz/lossy?status.svg)](https://godoc.org/github.com/cevatbarisyilmaz/lossy)

[![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/cevatbarisyilmaz/lossy?sort=semver)](https://github.com/cevatbarisyilmaz/lossy/releases)

[![GitHub](https://img.shields.io/github/license/cevatbarisyilmaz/lossy)](https://github.com/cevatbarisyilmaz/lossy/blob/master/LICENSE)

[![Go Report Card](https://goreportcard.com/badge/github.com/cevatbarisyilmaz/lossy)](https://goreportcard.com/report/github.com/cevatbarisyilmaz/lossy)

Go package to simulate bandwidth, latency and packet loss for net.PacketConn and net.Conn interfaces.

Its main usage is to test robustness of applications and network protocols run over unreliable transport protocols such as UDP or IP.

As a side benefit, it can also be used as outbound bandwidth limiter.

lossy only alters the writing side of the connection, reading side is kept as it is.

## Example

```go

package main

import (

	"fmt"

	"github.com/cevatbarisyilmaz/lossy"

	"log"

	"math/rand"

	"net"

	"time"

)

const packetSize = 64

func main() {

	// Create two connection endpoints over UDP

	packetConn, conn := createConnections()

	// Create a lossy packet connection

	bandwidth := 1048 // 8 Kbit/s

	minLatency := 100 * time.Millisecond

	maxLatency := time.Second

	packetLossRate := 0.33

	headerOverhead := lossy.UDPv4MinHeaderOverhead

	lossyPacketConn := lossy.NewPacketConn(packetConn, bandwidth, minLatency, maxLatency, packetLossRate, headerOverhead)

	// Write some packets via lossy

	var bytesWritten int

	const packetCount = 32

	go func() {

		for i := 0; i < packetCount; i++ {

			packet := createPacket()

			_, err := lossyPacketConn.WriteTo(packet, conn.LocalAddr())

			if err != nil {

				log.Fatal(err)

			}

			bytesWritten += len(packet) + headerOverhead

		}

		fmt.Println("Sent", packetCount, "packets with total size of", bytesWritten, "bytes")

		baseTransmissionDuration := time.Duration(float64(bytesWritten * int(time.Second)) / float64(bandwidth))

		earliestCompletion := baseTransmissionDuration + minLatency

		latestCompletion := baseTransmissionDuration + maxLatency

		fmt.Println("Expected transmission duration is between", earliestCompletion, "and", latestCompletion)

	}()

	// Read packets at the other side

	const timeout = 3 * time.Second

	var packets, bytesRead int

	startTime := time.Now()

	for {

		_ = conn.SetReadDeadline(time.Now().Add(timeout))

		buffer := make([]byte, packetSize)

		n, err := conn.Read(buffer)

		if err != nil {

			break

		}

		bytesRead += n + headerOverhead

		packets++

	}

	dur := time.Now().Sub(startTime) - timeout

	fmt.Println("Received", packets, "packets with total size of", bytesRead, "bytes in", dur)

	// Close the connections

	_ = lossyPacketConn.Close()

	_ = conn.Close()

}

func createConnections() (net.PacketConn, net.Conn) {

	packetConn, err := net.ListenUDP("udp", &net.UDPAddr{

		IP:   net.IPv4(127, 0, 0, 1),

		Port: 0,

	})

	if err != nil {

		log.Fatal(err)

	}

	conn, err := net.DialUDP("udp", nil, packetConn.LocalAddr().(*net.UDPAddr))

	if err != nil {

		log.Fatal(err)

	}

	return packetConn, conn

}

func createPacket() []byte {

	packet := make([]byte, packetSize)

	rand.Read(packet)

	return packet

}

```

Output

```

Sent 32 packets with total size of 2944 bytes

Expected transmission duration is between 2.909160305s and 3.809160305s

Received 23 packets with total size of 2116 bytes in 3.2507523s

```