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[1]: https://godoc.org/github.com/xtaci/smux?status.svg
[2]: https://godoc.org/github.com/xtaci/smux
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[4]: LICENSE
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[10]: https://codecov.io/gh/xtaci/smux
## Introduction
Smux ( **S**imple **MU**ltiple**X**ing) is a multiplexing library for Golang. It relies on an underlying connection to provide reliability and ordering, such as TCP or [KCP](https://github.com/xtaci/kcp-go), and provides stream-oriented multiplexing. The original intention of this library is to power the connection management for [kcp-go](https://github.com/xtaci/kcp-go).
## Features
1. Tiny, less than 600 LOC.
2. ***Token bucket*** controlled receiving, which provides smoother bandwidth graph(see picture below).
3. Session-wide receive buffer, shared among streams, tightly controlled overall memory usage.
4. Minimized header(8Bytes), maximized payload.
5. Well-tested on millions of devices in [kcptun](https://github.com/xtaci/kcptun).
## Documentation
For complete documentation, see the associated [Godoc](https://godoc.org/github.com/xtaci/smux).
## Specification
```
VERSION(1B) | CMD(1B) | LENGTH(2B) | STREAMID(4B) | DATA(LENGTH)
```
## Usage
The API of smux are mostly taken from [yamux](https://github.com/hashicorp/yamux)
```go
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)
}
```
## Status
Stable