/
server.go
243 lines (207 loc) · 5.61 KB
/
server.go
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// Copyright (c) 2022-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.
package ws
import (
"fmt"
"net/http"
"sync"
"time"
"github.com/mattermost/rtcd/service/random"
"github.com/gorilla/websocket"
"github.com/mattermost/mattermost/server/public/shared/mlog"
)
const (
ReceiveChSize = 512
sendChSize = ReceiveChSize
writeWaitTime = 10 * time.Second
)
type AuthCb func(w http.ResponseWriter, r *http.Request) (string, int, error)
type Server struct {
cfg ServerConfig
log mlog.LoggerIFace
conns map[string]*conn
authCb AuthCb
mut sync.RWMutex
sendCh chan Message
receiveCh chan Message
closed bool
}
// NewServer initializes and returns a new WebSocket server.
func NewServer(cfg ServerConfig, log mlog.LoggerIFace, opts ...ServerOption) (*Server, error) {
if err := cfg.IsValid(); err != nil {
return nil, fmt.Errorf("failed to validate config: %w", err)
}
s := &Server{
cfg: cfg,
log: log,
conns: make(map[string]*conn),
sendCh: make(chan Message, sendChSize),
receiveCh: make(chan Message, ReceiveChSize),
}
for _, opt := range opts {
if err := opt(s); err != nil {
return nil, fmt.Errorf("failed to apply option: %w", err)
}
}
go s.connWriter()
return s, nil
}
// SendCh queues a message to be sent through a ws connection.
func (s *Server) Send(msg Message) error {
s.mut.RLock()
defer s.mut.RUnlock()
if s.closed {
return fmt.Errorf("server is closed")
}
select {
case s.sendCh <- msg:
default:
return fmt.Errorf("failed to send ws message, channel is full")
}
return nil
}
// ReceiveCh returns a channel that can be used to receive messages from ws connections.
func (s *Server) ReceiveCh() <-chan Message {
return s.receiveCh
}
// Close stops the websocket server and closes all the ws connections.
// Must be called once all senders are done.
func (s *Server) Close() {
s.mut.Lock()
if s.closed {
s.mut.Unlock()
return
}
s.closed = true
s.mut.Unlock()
conns := s.getConns()
for _, conn := range conns {
if err := conn.close(); err != nil {
s.log.Error("failed to close ws conn", mlog.Err(err))
}
<-conn.closeCh
}
close(s.receiveCh)
close(s.sendCh)
}
// ServeHTTP makes the WebSocket server implement http.Handler so that it can
// be passed to a RegisterHandler method.
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
connID := random.NewID()
sendOpenMsg := func(clientID string) {
s.receiveCh <- newOpenMessage(connID, clientID)
}
sendCloseMsg := func(clientID string) {
s.receiveCh <- newCloseMessage(connID, clientID)
}
var err error
var clientID string
if s.authCb != nil {
clientID, _, err = s.authCb(w, r)
if err != nil {
s.log.Error("authCb failed", mlog.Err(err))
return
}
}
upgrader := websocket.Upgrader{
ReadBufferSize: s.cfg.ReadBufferSize,
WriteBufferSize: s.cfg.WriteBufferSize,
}
ws, err := upgrader.Upgrade(w, r, nil)
if err != nil {
s.log.Error("failed to upgrade connection", mlog.Err(err))
sendCloseMsg(clientID)
return
}
conn := newConn(connID, clientID, ws)
defer conn.close()
defer close(conn.closeCh)
s.addConn(conn)
if s.isClosed() {
return
}
sendOpenMsg(clientID)
defer s.removeConn(conn.id)
defer sendCloseMsg(clientID)
ws.SetReadLimit(connMaxReadBytes)
if err := ws.SetReadDeadline(time.Now().Add(2 * s.cfg.PingInterval)); err != nil {
s.log.Error("failed to set read deadline", mlog.Err(err))
return
}
ws.SetPongHandler(func(appData string) error {
return ws.SetReadDeadline(time.Now().Add(2 * s.cfg.PingInterval))
})
for {
mt, data, err := ws.ReadMessage()
if err != nil {
s.log.Error("ws read failed", mlog.Err(err))
break
}
var msgType MessageType
switch mt {
case websocket.TextMessage:
msgType = TextMessage
case websocket.BinaryMessage:
msgType = BinaryMessage
default:
s.log.Error("unexpected ws message", mlog.Int("type", mt))
continue
}
s.receiveCh <- Message{
ConnID: connID,
ClientID: conn.clientID,
Type: msgType,
Data: data,
}
}
}
func (s *Server) connWriter() {
pingTicker := time.NewTicker(s.cfg.PingInterval)
defer pingTicker.Stop()
for {
select {
case msg, ok := <-s.sendCh:
if !ok {
return
}
conn := s.getConn(msg.ConnID)
if conn == nil {
s.log.Error("failed to get conn for sending", mlog.String("connID", msg.ConnID), mlog.String("clientID", msg.ClientID))
continue
}
var msgType int
switch msg.Type {
case TextMessage:
msgType = websocket.TextMessage
case BinaryMessage:
msgType = websocket.BinaryMessage
case CloseMessage:
msgType = websocket.CloseMessage
default:
s.log.Error("unexpected ws message", mlog.Int("type", int(msg.Type)))
continue
}
if err := conn.ws.SetWriteDeadline(time.Now().Add(writeWaitTime)); err != nil {
s.log.Error("failed to set write deadline", mlog.String("connID", msg.ConnID), mlog.Err(err))
}
if err := conn.ws.WriteMessage(msgType, msg.Data); err != nil {
s.log.Error("failed to write message", mlog.String("connID", msg.ConnID), mlog.Err(err))
}
case <-pingTicker.C:
conns := s.getConns()
for _, conn := range conns {
if err := conn.ws.SetWriteDeadline(time.Now().Add(writeWaitTime)); err != nil {
s.log.Error("failed to set write deadline", mlog.String("connID", conn.id), mlog.Err(err))
}
if err := conn.ws.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
s.log.Error("failed to write ping message", mlog.String("connID", conn.id), mlog.Err(err))
}
}
}
}
}
func (s *Server) isClosed() bool {
s.mut.RLock()
defer s.mut.RUnlock()
return s.closed
}