The smux from lubyruffy

smux's Introduction

Introduction

Smux ( Simple MUltipleXing) is a multiplexing library for Golang. It relies on an underlying connection to provide reliability and ordering, such as TCP or KCP, and provides stream-oriented multiplexing. The original intention of this library is to power the connection management for kcp-go.

Features

Tiny, less than 600 LOC.
Token bucket controlled receiving, which provides smoother bandwidth graph(see picture below).
Session-wide receive buffer, shared among streams, tightly controlled overall memory usage.
Minimized header(8Bytes), maximized payload.
Well-tested on millions of devices in kcptun.

Documentation

For complete documentation, see the associated Godoc.

Specification

VERSION(1B) | CMD(1B) | LENGTH(2B) | STREAMID(4B) | DATA(LENGTH)

Usage

The API of smux are mostly taken from yamux

func client() {
    // Get a TCP connection
    conn, err := net.Dial(...)
    if err != nil {
        panic(err)
    }

    // Setup client side of smux
    session, err := smux.Client(conn, nil)
    if err != nil {
        panic(err)
    }

    // Open a new stream
    stream, err := session.OpenStream()
    if err != nil {
        panic(err)
    }

    // Stream implements io.ReadWriteCloser
    stream.Write([]byte("ping"))
}

func server() {
    // Accept a TCP connection
    conn, err := listener.Accept()
    if err != nil {
        panic(err)
    }

    // Setup server side of smux
    session, err := smux.Server(conn, nil)
    if err != nil {
        panic(err)
    }

    // Accept a stream
    stream, err := session.AcceptStream()
    if err != nil {
        panic(err)
    }

    // Listen for a message
    buf := make([]byte, 4)
    stream.Read(buf)
}