gev

README

gev

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gev is a lightweight, fast non-blocking TCP network library / websocket server based on Reactor mode.

Support custom protocols to quickly and easily build high-performance servers.

Features

• High-performance event loop based on epoll and kqueue
• Support multi-core and multi-threading
• Dynamic expansion of read and write buffers implemented by Ring Buffer
• Asynchronous read and write
• SO_REUSEPORT port reuse support
• Automatically clean up idle connections
• Support WebSocket/Protobuf, custom protocols
• Support for scheduled tasks, delayed tasks
• High performance websocket server

Network model

gev uses only a few goroutines, one of them listens for connections and the others (work coroutines) handle read and write events of connected clients. The count of work coroutines is configurable, which is the core number of host CPUs by default.

Performance Test

📈 Test chart

Test environment: Ubuntu18.04 | 4 Virtual CPUs | 4.0 GiB

Throughput Test

limit GOMAXPROCS=1（Single thread），1 work goroutine

limit GOMAXPROCS=4，4 work goroutine

Other Test

Speed ​​Test

Compared with the simple performance of similar libraries, the pressure measurement method is the same as the evio project.

• gnet
• eviop
• evio
• net (StdLib)

limit GOMAXPROCS=1，1 work goroutine

limit GOMAXPROCS=1，4 work goroutine

limit GOMAXPROCS=4，4 work goroutine

Install

go get -u github.com/Allenxuxu/gev

Getting start

echo demo

package main

import (
	"flag"
	"net/http"
	_ "net/http/pprof"
	"strconv"
	"time"

	"github.com/Allenxuxu/gev"
	"github.com/Allenxuxu/gev/log"
	"github.com/Allenxuxu/toolkit/sync/atomic"
)

type example struct {
	Count atomic.Int64
}

func (s *example) OnConnect(c *gev.Connection) {
	s.Count.Add(1)
	//log.Println(" OnConnect ： ", c.PeerAddr())
}
func (s *example) OnMessage(c *gev.Connection, ctx interface{}, data []byte) (out interface{}) {
	//log.Println("OnMessage")
	out = data
	return
}

func (s *example) OnClose(c *gev.Connection) {
	s.Count.Add(-1)
	//log.Println("OnClose")
}

func main() {
	go func() {
		if err := http.ListenAndServe(":6060", nil); err != nil {
			panic(err)
		}
	}()

	handler := new(example)
	var port int
	var loops int

	flag.IntVar(&port, "port", 1833, "server port")
	flag.IntVar(&loops, "loops", -1, "num loops")
	flag.Parse()

	s, err := gev.NewServer(handler,
		gev.Network("tcp"),
		gev.Address(":"+strconv.Itoa(port)),
		gev.NumLoops(loops),
		gev.MetricsServer("", ":9091"),
	)
	if err != nil {
		panic(err)
	}

	s.RunEvery(time.Second*2, func() {
		log.Info("connections :", handler.Count.Get())
	})

	s.Start()
}

Handler is an interface that programs must implement.

type CallBack interface {
	OnMessage(c *Connection, ctx interface{}, data []byte) interface{}
	OnClose(c *Connection)
}

type Handler interface {
	CallBack
	OnConnect(c *Connection)
}

OnMessage will be called back when a complete data frame arrives.Users can get the data, process the business logic, and return the data that needs to be sent.

When there is data coming, gev does not call back OnMessage immediately, but instead calls back an UnPacket function.Probably the execution logic is as follows:

ctx, receivedData := c.protocol.UnPacket(c, buffer)
for ctx != nil || len(receivedData) != 0 {
	sendData := c.callBack.OnMessage(c, ctx, receivedData)
	if sendData != nil {
		*tmpBuffer = append(*tmpBuffer, c.protocol.Packet(c, sendData)...)
	}

	ctx, receivedData = c.protocol.UnPacket(c, buffer)
}

The UnPacket function will check whether the data in the ringbuffer is a complete data frame. If it is, the data will be unpacked and return the payload data. If it is not a complete data frame, it will return directly.

The return value of UnPacket (interface{}, []byte) will be passed in as a call to OnMessage ctx interface{}, data []byte and callback.Ctx is designed to pass special information generated when parsing data frames in the UnPacket function (which is required for complex data frame protocols), and data is used to pass payload data.

type Protocol interface {
	UnPacket(c *Connection, buffer *ringbuffer.RingBuffer) (interface{}, []byte)
	Packet(c *Connection, data interface{}) []byte
}

type DefaultProtocol struct{}

func (d *DefaultProtocol) UnPacket(c *Connection, buffer *ringbuffer.RingBuffer) (interface{}, []byte) {
	s, e := buffer.PeekAll()
	if len(e) > 0 {
		size := len(s) + len(e)
		userBuffer := *c.UserBuffer()
		if size > cap(userBuffer) {
			userBuffer = make([]byte, size)
			*c.UserBuffer() = userBuffer
		}

		copy(userBuffer, s)
		copy(userBuffer[len(s):], e)

		return nil, userBuffer
	} else {
		buffer.RetrieveAll()

		return nil, s
	}
}

func (d *DefaultProtocol) Packet(c *Connection, data interface{}) []byte {
	return data.([]byte)
}

As above, gev provides a default Protocol implementation that will fetch all data in the receive buffer ( ringbuffer ).In actual use, there is usually a data frame protocol of its own, and gev can be set in the form of a plug-in: it is set by variable parameters when creating Server.

s, err := gev.NewServer(handler,gev.Protocol(&ExampleProtocol{}))

Check out the example Protocol for a detailed.

There is also a Send method that can be used for sending data. But Send puts the data to Event-Loop and invokes it to send the data rather than sending data by itself immediately.

Check out the example Server timing push for a detailed.

func (c *Connection) Send(data interface{}, opts ...ConnectionOption) error

ShutdownWrite works for reverting connected status to false and closing connection.

Check out the example Maximum connections for a detailed.

func (c *Connection) ShutdownWrite() error

RingBuffer is a dynamical expansion implementation of circular buffer.

WebSocket

The WebSocket protocol is built on top of the TCP protocol, so gev doesn't need to be built in, but instead provides support in the form of plugins, in the plugins/websocket directory.

code

type Protocol struct {
	upgrade *ws.Upgrader
}

func New(u *ws.Upgrader) *Protocol {
	return &Protocol{upgrade: u}
}

func (p *Protocol) UnPacket(c *connection.Connection, buffer *ringbuffer.RingBuffer) (ctx interface{}, out []byte) {
	upgraded := c.Context()
	if upgraded == nil {
		var err error
		out, _, err = p.upgrade.Upgrade(buffer)
		if err != nil {
			log.Println("Websocket Upgrade :", err)
			return
		}
		c.SetContext(true)
	} else {
		header, err := ws.VirtualReadHeader(buffer)
		if err != nil {
			log.Println(err)
			return
		}
		if buffer.VirtualLength() >= int(header.Length) {
			buffer.VirtualFlush()

			payload := make([]byte, int(header.Length))
			_, _ = buffer.Read(payload)

			if header.Masked {
				ws.Cipher(payload, header.Mask, 0)
			}

			ctx = &header
			out = payload
		} else {
			buffer.VirtualRevert()
		}
	}
	return
}

func (p *Protocol) Packet(c *connection.Connection, data []byte) []byte {
	return data
}

The detailed implementation can be viewed by the plugin. The source code can be viewed using the websocket example.

Example

• Echo Server
• Automatically clean up idle connections
• Maximum connections
• Server timing push
• WebSocket
• Protobuf
• ...

Buy me a coffee

Paypal: Paypal/AllenXuxu

Thanks

Thanks JetBrains for the free open source license

References

• evio
• muduo

Documentation

Index

• Variables
• type CallBack
• type Connection
  • func NewConnection(fd int, loop *eventloop.EventLoop, sa unix.Sockaddr, protocol Protocol, ...) *Connection
  • func (c *Connection) Close() error
  • func (c *Connection) Connected() bool
  • func (c *Connection) Context() interface{}
  • func (c *Connection) HandleEvent(fd int, events poller.Event)
  • func (c *Connection) PeerAddr() string
  • func (c *Connection) ReadBufferLength() int64
  • func (c *Connection) Send(data interface{}, opts ...ConnectionOption) error
  • func (c *Connection) SetContext(ctx interface{})
  • func (c *Connection) ShutdownWrite() error
  • func (c *Connection) UserBuffer() *[]byte
  • func (c *Connection) WriteBufferLength() int64
• type ConnectionOption
  • func SendInLoop(f SendInLoopFunc) ConnectionOption
• type ConnectionOptions
• type DefaultProtocol
  • func (d *DefaultProtocol) Packet(c *Connection, data interface{}) []byte
  • func (d *DefaultProtocol) UnPacket(c *Connection, buffer *ringbuffer.RingBuffer) (interface{}, []byte)
• type Handler
• type KeyValueContext
  • func (c *KeyValueContext) Delete(key string)
  • func (c *KeyValueContext) Get(key string) (value interface{}, exists bool)
  • func (c *KeyValueContext) Set(key string, value interface{})
• type LoadBalanceStrategy
  • func LeastConnection() LoadBalanceStrategy
  • func RoundRobin() LoadBalanceStrategy
• type Option
  • func Address(a string) Option
  • func CustomProtocol(p Protocol) Option
  • func IdleTime(t time.Duration) Option
  • func LoadBalance(strategy LoadBalanceStrategy) Option
  • func MetricsServer(path, address string) Option
  • func Network(n string) Option
  • func NumLoops(n int) Option
  • func ReusePort(reusePort bool) Option
• type Options
• type Protocol
• type SendInLoopFunc
• type Server
  • func NewServer(handler Handler, opts ...Option) (server *Server, err error)
  • func (s *Server) Options() Options
  • func (s *Server) RunAfter(d time.Duration, f func()) *timingwheel.Timer
  • func (s *Server) RunEvery(d time.Duration, f func()) *timingwheel.Timer
  • func (s *Server) Start()
  • func (s *Server) Stop()

Examples

• Server.RunAfter
• Server.RunEvery

Variables

var ErrConnectionClosed = errors.New("connection closed")

Types

type CallBack

type CallBack interface {
	OnMessage(c *Connection, ctx interface{}, data []byte) interface{}
	OnClose(c *Connection)
}

type Connection

type Connection struct {
	KeyValueContext
	// contains filtered or unexported fields
}

Connection TCP 连接

func NewConnection

func NewConnection(fd int,
	loop *eventloop.EventLoop,
	sa unix.Sockaddr,
	protocol Protocol,
	tw *timingwheel.TimingWheel,
	idleTime time.Duration,
	callBack CallBack) *Connection

NewConnection 创建 Connection

func (*Connection) Close

func (c *Connection) Close() error

Close 关闭连接

func (*Connection) Connected

func (c *Connection) Connected() bool

Connected 是否已连接

func (*Connection) Context

func (c *Connection) Context() interface{}

Context 获取 Context

func (*Connection) HandleEvent

func (c *Connection) HandleEvent(fd int, events poller.Event)

HandleEvent 内部使用，event loop 回调

func (*Connection) PeerAddr

func (c *Connection) PeerAddr() string

PeerAddr 获取客户端地址信息

func (*Connection) ReadBufferLength

func (c *Connection) ReadBufferLength() int64

ReadBufferLength read buffer 当前积压的数据长度

func (*Connection) Send

func (c *Connection) Send(data interface{}, opts ...ConnectionOption) error

Send 用来在非 loop 协程发送

func (*Connection) SetContext

func (c *Connection) SetContext(ctx interface{})

SetContext 设置 Context

func (*Connection) ShutdownWrite

func (c *Connection) ShutdownWrite() error

ShutdownWrite 关闭可写端，等待读取完接收缓冲区所有数据

func (*Connection) UserBuffer

func (c *Connection) UserBuffer() *[]byte

func (*Connection) WriteBufferLength

func (c *Connection) WriteBufferLength() int64

WriteBufferLength write buffer 当前积压的数据长度

type ConnectionOption

type ConnectionOption func(*ConnectionOptions)

func SendInLoop

func SendInLoop(f SendInLoopFunc) ConnectionOption

type ConnectionOptions

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

type DefaultProtocol

type DefaultProtocol struct{}

DefaultProtocol 默认 Protocol

func (*DefaultProtocol) Packet

func (d *DefaultProtocol) Packet(c *Connection, data interface{}) []byte

Packet 封包

func (*DefaultProtocol) UnPacket

func (d *DefaultProtocol) UnPacket(c *Connection, buffer *ringbuffer.RingBuffer) (interface{}, []byte)

UnPacket 拆包

type Handler

type Handler interface {
	CallBack
	OnConnect(c *Connection)
}

Handler Server 注册接口

type KeyValueContext

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

func (*KeyValueContext) Delete

func (c *KeyValueContext) Delete(key string)

func (*KeyValueContext) Get

func (c *KeyValueContext) Get(key string) (value interface{}, exists bool)

func (*KeyValueContext) Set

func (c *KeyValueContext) Set(key string, value interface{})

type LoadBalanceStrategy

type LoadBalanceStrategy func([]*eventloop.EventLoop) *eventloop.EventLoop

func LeastConnection

func LeastConnection() LoadBalanceStrategy

func RoundRobin

func RoundRobin() LoadBalanceStrategy

type Option

type Option func(*Options)

Option ...

func Address

func Address(a string) Option

Address server 监听地址

func CustomProtocol

func CustomProtocol(p Protocol) Option

CustomProtocol 数据包处理

func IdleTime

func IdleTime(t time.Duration) Option

IdleTime 最大空闲时间（秒）

func LoadBalance

func LoadBalance(strategy LoadBalanceStrategy) Option

func MetricsServer

func MetricsServer(path, address string) Option

func Network

func Network(n string) Option

Network [tcp] 暂时只支持tcp

func NumLoops

func NumLoops(n int) Option

NumLoops work eventloop 的数量

func ReusePort

func ReusePort(reusePort bool) Option

ReusePort 设置 SO_REUSEPORT

type Options

type Options struct {
	Network   string
	Address   string
	NumLoops  int
	ReusePort bool
	IdleTime  time.Duration
	Protocol  Protocol
	Strategy  LoadBalanceStrategy
	// contains filtered or unexported fields
}

Options 服务配置

type Protocol

type Protocol interface {
	UnPacket(c *Connection, buffer *ringbuffer.RingBuffer) (interface{}, []byte)
	Packet(c *Connection, data interface{}) []byte
}

Protocol 自定义协议编解码接口

type SendInLoopFunc

type SendInLoopFunc func(interface{})

type Server

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

Server gev Server

func NewServer

func NewServer(handler Handler, opts ...Option) (server *Server, err error)

NewServer 创建 Server

func (*Server) Options

func (s *Server) Options() Options

Options 返回 options

func (*Server) RunAfter

func (s *Server) RunAfter(d time.Duration, f func()) *timingwheel.Timer

RunAfter 延时任务

Example

handler := new(example)

s, err := NewServer(handler,
	Network("tcp"),
	Address(":1833"),
	NumLoops(8),
	ReusePort(true))
if err != nil {
	panic(err)
}

go s.Start()
defer s.Stop()

s.RunAfter(time.Second, func() {
	fmt.Println("RunAfter")
})

time.Sleep(2500 * time.Millisecond)

Output:

RunAfter

func (*Server) RunEvery

func (s *Server) RunEvery(d time.Duration, f func()) *timingwheel.Timer

RunEvery 定时任务

Example

handler := new(example)

s, err := NewServer(handler,
	Network("tcp"),
	Address(":1833"),
	NumLoops(8),
	ReusePort(true))
if err != nil {
	panic(err)
}

go s.Start()
defer s.Stop()

t := s.RunEvery(time.Second, func() {
	fmt.Println("EveryFunc")
})

time.Sleep(4500 * time.Millisecond)
t.Stop()
time.Sleep(4500 * time.Millisecond)

Output:

EveryFunc
EveryFunc
EveryFunc
EveryFunc

func (*Server) Start

func (s *Server) Start()

Start 启动 Server

func (*Server) Stop

func (s *Server) Stop()

Stop 关闭 Server