// newSocket creates a new socket and initializes it.
func newSocket(server *Server, bs backend.BackendSocket) *Socket {
// Create a new socket value.
s := &Socket{
server: server,
bs: bs,
id: utils.RandomString(socketIDLength),
channels: newChannels(),
writeChan: bs.WriteChan(),
readChan: bs.ReadChan(),
isClosedChan: make(chan struct{}),
pingTimer: time.NewTimer(pingPeriod),
pingTimeout: time.NewTimer(pingResponseTimeout),
}
// Create the main channel.
s.mainChannel = s.Channel(mainChannelName)
// Set the event functions.
bs.OnClose(s.onClose)
// Stop the timeout again. It will be started by the ping timer.
s.pingTimeout.Stop()
// Add the new socket to the active sockets map.
// If the ID is already present, then generate a new one.
func() {
// Lock the mutex.
s.server.socketsMutex.Lock()
defer s.server.socketsMutex.Unlock()
// Be sure that the ID is unique.
for {
if _, ok := s.server.sockets[s.id]; !ok {
break
}
s.id = utils.RandomString(socketIDLength)
}
// Add the socket to the map.
s.server.sockets[s.id] = s
}()
// Start the loops and handlers in new goroutines.
go s.pingTimeoutHandler()
go s.readLoop()
go s.pingLoop()
return s
}
func (s *Server) initAjaxRequest(remoteAddr, userAgent string, w http.ResponseWriter) {
var uid string
// Create a new ajax socket value.
a := newSocket(s)
a.remoteAddr = remoteAddr
a.userAgent = userAgent
func() {
// Lock the mutex
s.socketsMutex.Lock()
defer s.socketsMutex.Unlock()
// Obtain a new unique ID.
for {
// Generate it.
uid = utils.RandomString(ajaxUIDLength)
// Check if the new UID is already used.
// This is very unlikely, but we have to check this!
_, ok := s.sockets[uid]
if !ok {
// Break the loop if the UID is unique.
break
}
}
// Set the UID.
a.uid = uid
// Add the new ajax socket to the map.
s.sockets[uid] = a
}()
// Create a new poll token.
a.pollToken = utils.RandomString(ajaxPollTokenLength)
// Tell the client the UID and poll token.
io.WriteString(w, uid+ajaxSocketDataDelimiter+a.pollToken)
// Trigger the event that a new socket connection was made.
s.onNewSocketConnection(a)
}
func (s *Server) pollAjaxRequest(uid, remoteAddr, userAgent, data string, w http.ResponseWriter) {
// Obtain the ajax socket with the uid.
a := func() *Socket {
// Lock the mutex.
s.socketsMutex.Lock()
defer s.socketsMutex.Unlock()
// Obtain the ajax socket with the uid-
a, ok := s.sockets[uid]
if !ok {
return nil
}
return a
}()
if a == nil {
log.L.WithFields(logrus.Fields{
"remoteAddress": remoteAddr,
"userAgent": userAgent,
"uid": uid,
}).Warningf("ajax: client requested an invalid ajax socket: uid is invalid!")
http.Error(w, "Bad Request", 400)
return
}
// The user agents have to match.
if a.userAgent != userAgent {
log.L.WithFields(logrus.Fields{
"remoteAddress": remoteAddr,
"userAgent": userAgent,
"uid": uid,
"clientUserAgent": userAgent,
"socketUserAgent": a.userAgent,
}).Warningf("ajax: client poll request: user agents do not match!")
http.Error(w, "Bad Request", 400)
return
}
// Check if the poll tokens matches.
// The poll token is the data value.
if a.pollToken != data {
log.L.WithFields(logrus.Fields{
"remoteAddress": remoteAddr,
"userAgent": userAgent,
"uid": uid,
"clientPollToken": data,
"socketPollToken": a.pollToken,
}).Warningf("ajax: client poll request: poll tokens do not match!")
http.Error(w, "Bad Request", 400)
return
}
// Create a new poll token.
a.pollToken = utils.RandomString(ajaxPollTokenLength)
// Create a timeout timer for the poll.
timeout := time.NewTimer(ajaxPollTimeout)
defer func() {
// Stop the timeout timer.
timeout.Stop()
}()
// Send messages as soon as there are some available.
select {
case data := <-a.writeChan:
// Send the new poll token and message data to the client.
io.WriteString(w, a.pollToken+ajaxSocketDataDelimiter+data)
case <-timeout.C:
// Tell the client that this ajax connection has reached the timeout.
io.WriteString(w, ajaxPollCmdTimeout)
case <-a.closer.IsClosedChan:
// Tell the client that this ajax connection is closed.
io.WriteString(w, ajaxPollCmdClosed)
}
}