use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/lucas-clemente/quic-go/conn.go

@@ -0,0 +1,54 @@
+package quic
+
+import (
+	"net"
+	"sync"
+)
+
+type connection interface {
+	Write([]byte) error
+	Read([]byte) (int, net.Addr, error)
+	Close() error
+	LocalAddr() net.Addr
+	RemoteAddr() net.Addr
+	SetCurrentRemoteAddr(net.Addr)
+}
+
+type conn struct {
+	mutex sync.RWMutex
+
+	pconn       net.PacketConn
+	currentAddr net.Addr
+}
+
+var _ connection = &conn{}
+
+func (c *conn) Write(p []byte) error {
+	_, err := c.pconn.WriteTo(p, c.currentAddr)
+	return err
+}
+
+func (c *conn) Read(p []byte) (int, net.Addr, error) {
+	return c.pconn.ReadFrom(p)
+}
+
+func (c *conn) SetCurrentRemoteAddr(addr net.Addr) {
+	c.mutex.Lock()
+	c.currentAddr = addr
+	c.mutex.Unlock()
+}
+
+func (c *conn) LocalAddr() net.Addr {
+	return c.pconn.LocalAddr()
+}
+
+func (c *conn) RemoteAddr() net.Addr {
+	c.mutex.RLock()
+	addr := c.currentAddr
+	c.mutex.RUnlock()
+	return addr
+}
+
+func (c *conn) Close() error {
+	return c.pconn.Close()
+}