3
0
corteza/sam/websocket/session.go

130 lines
2.4 KiB
Go

package websocket
import (
"context"
"log"
"time"
"github.com/gorilla/websocket"
"github.com/pkg/errors"
"github.com/crusttech/crust/sam/websocket/outgoing"
)
type (
// Session
Session struct {
id uint64
conn *websocket.Conn
ctx context.Context
subs *Subscriptions
send chan []byte
stop chan []byte
remoteAddr string
config configuration
}
)
func (Session) New(ctx context.Context, conn *websocket.Conn) *Session {
return &Session{
conn: conn,
ctx: ctx,
config: config,
subs: Subscriptions{}.New(),
send: make(chan []byte, 512),
stop: make(chan []byte, 1),
}
}
func (sess *Session) Context() context.Context {
return sess.ctx
}
func (sess *Session) Handle() error {
go sess.readLoop()
return sess.writeLoop()
}
func (sess *Session) Close() {
sess.conn.Close()
}
func (sess *Session) readLoop() error {
defer func() {
log.Println("serveWebsocket - stop")
sess.Close()
}()
sess.conn.SetReadDeadline(time.Now().Add(sess.config.pingTimeout))
sess.conn.SetPongHandler(func(string) error {
sess.conn.SetReadDeadline(time.Now().Add(sess.config.pingTimeout))
return nil
})
sess.remoteAddr = sess.conn.RemoteAddr().String()
for {
_, raw, err := sess.conn.ReadMessage()
if err != nil {
return errors.Wrap(err, "sess.readLoop")
}
if err := sess.dispatch(raw); err != nil {
// @todo: log error?
sess.send <- func() []byte {
b, _ := outgoing.NewError(err).EncodeMessage()
return b
}()
}
}
}
func (sess *Session) writeLoop() error {
ticker := time.NewTicker(sess.config.pingPeriod)
defer func() {
ticker.Stop()
sess.Close() // break readLoop
}()
write := func(msg []byte) error {
sess.conn.SetWriteDeadline(time.Now().Add(sess.config.writeTimeout))
if msg != nil {
return sess.conn.WriteMessage(websocket.TextMessage, msg)
}
return nil
}
ping := func() error {
sess.conn.SetWriteDeadline(time.Now().Add(sess.config.writeTimeout))
return sess.conn.WriteMessage(websocket.PingMessage, nil)
}
for {
select {
case msg, ok := <-sess.send:
if !ok {
// channel closed
return nil
}
if err := write(msg); err != nil {
return errors.Wrap(err, "writeLoop send")
}
case msg := <-sess.stop:
// Shutdown requested, don't care if the message is delivered
write(msg)
return nil
case <-ticker.C:
if err := ping(); err != nil {
return errors.Wrap(err, "writeLoop ping")
}
}
}
}