/
mux.go
110 lines (98 loc) · 2.12 KB
/
mux.go
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package transport
import (
"net"
"sync"
"github.com/xtaci/smux/v2"
"golang.org/x/sync/singleflight"
)
// A plugable mux for transport layer
type DialFunc func(addr string) (net.Conn, error)
type ListenFunc func(addr string) (net.Listener, error)
func WithMuxDial(f DialFunc) DialFunc {
conns := new(sync.Map)
var g singleflight.Group
return func(addr string) (c net.Conn, err error) {
ret, ok := conns.Load(addr)
if !ok || ret.(*smux.Session).IsClosed() {
if ret, err, _ = g.Do("addr", genDialFunc(addr, f, conns)); err != nil {
return nil, err
}
}
return ret.(*smux.Session).OpenStream()
}
}
func genDialFunc(addr string, f DialFunc, conns *sync.Map) func() (interface{}, error) {
return func() (interface{}, error) {
c, err := f(addr)
if err != nil {
return nil, err
}
s, err := smux.Client(c, smux.DefaultConfig())
if err != nil {
return nil, err
}
conns.Store(addr, s)
return s, nil
}
}
type muxListener struct {
net.Listener
conns *sync.Map
connChannel chan net.Conn
errorChannel chan error
}
func WithMuxListen(f ListenFunc) ListenFunc {
return func(addr string) (net.Listener, error) {
l, err := f(addr)
if err != nil {
return nil, err
}
ret := &muxListener{
Listener: l,
conns: new(sync.Map),
connChannel: make(chan net.Conn, 10),
errorChannel: make(chan error, 10),
}
go ret.serve()
return ret, nil
}
}
func (l *muxListener) Accept() (net.Conn, error) {
select {
case c := <-l.connChannel:
return c, nil
case err := <-l.errorChannel:
return nil, err
}
}
func (l *muxListener) serve() {
for {
ss, err := l.acceptSession()
if err != nil {
l.errorChannel <- err
continue
}
go l.serveSession(ss)
}
}
func (l *muxListener) serveSession(ss *smux.Session) {
for !ss.IsClosed() {
s, err := ss.AcceptStream()
if err != nil {
l.errorChannel <- err
continue
}
l.connChannel <- s
}
}
func (l *muxListener) acceptSession() (*smux.Session, error) {
c, err := l.Listener.Accept()
if err != nil {
return nil, err
}
ss, err := smux.Server(c, smux.DefaultConfig())
if err != nil {
return nil, err
}
return ss, nil
}