func (s *Server) subscribe(w http.ResponseWriter, r *http.Request) {
if _, ok := w.(http.Flusher); !ok {
http.Error(w, "streaming unsupported", http.StatusInternalServerError)
return
}
rd, err := s.newReader(w, r)
if rd != nil {
defer rd.Close()
}
if err != nil {
handleError(w, r, err)
return
}
_, err = io.Copy(newWriteFlusher(w), rd)
netErr, ok := err.(net.Error)
if ok && netErr.Timeout() {
util.CountWithData("server.sub.read.timeout", 1, "msg=%q request_id=%q", err, r.Header.Get("Request-Id"))
return
}
if err != nil {
rollbar.Error(rollbar.ERR, fmt.Errorf("unhandled error: %#v", err))
}
util.CountWithData("server.sub.read.finish", 1, "msg=%q request_id=%q", err, r.Header.Get("Request-Id"))
}
func storeOutput(channel string, requestURI string) {
if buf, err := broker.Get(channel); err == nil {
if err := storage.Put(requestURI, bytes.NewBuffer(buf)); err != nil {
util.CountWithData("server.storeOutput.put.error", 1, "err=%s", err.Error())
}
} else {
util.CountWithData("server.storeOutput.get.error", 1, "err=%s", err.Error())
}
}
func (s *Server) publish(w http.ResponseWriter, r *http.Request) {
if !util.StringInSlice(r.TransferEncoding, "chunked") {
http.Error(w, "A chunked Transfer-Encoding header is required.", http.StatusBadRequest)
return
}
writer, err := broker.NewWriter(key(r))
if err != nil {
handleError(w, r, err)
return
}
body := bufio.NewReader(r.Body)
defer r.Body.Close()
wl, err := broker.Len(writer)
if err != nil {
handleError(w, r, err)
return
}
if wl > 0 {
_, err = body.Discard(int(wl))
if err != nil {
handleError(w, r, err)
return
}
}
_, err = io.Copy(writer, body)
if err == io.ErrUnexpectedEOF {
util.CountWithData("server.pub.read.eoferror", 1, "msg=%q request_id=%q", err, r.Header.Get("Request-Id"))
return
}
netErr, ok := err.(net.Error)
if ok && netErr.Timeout() {
util.CountWithData("server.pub.read.timeout", 1, "msg=%q request_id=%q", err, r.Header.Get("Request-Id"))
handleError(w, r, netErr)
return
}
if err != nil {
log.Printf("%#v", err)
http.Error(w, "Unhandled error, please try again.", http.StatusInternalServerError)
rollbar.Error(rollbar.ERR, fmt.Errorf("unhandled error: %#v", err))
return
}
util.CountWithData("server.pub.read.end", 1, "request_id=%q", r.Header.Get("Request-Id"))
writer.Close()
// Asynchronously upload the output to our defined storage backend.
go storeOutput(key(r), requestURI(r), s.StorageBaseURL)
}
func mkstream(w http.ResponseWriter, _ *http.Request) {
registrar := broker.NewRedisRegistrar()
uuid, err := util.NewUUID()
if err != nil {
http.Error(w, "Unable to create stream. Please try again.", http.StatusServiceUnavailable)
rollbar.Error(rollbar.ERR, fmt.Errorf("unable to create new uuid for stream: %#v", err))
util.CountWithData("mkstream.create.fail", 1, "error=%s", err)
return
}
if err := registrar.Register(uuid); err != nil {
http.Error(w, "Unable to create stream. Please try again.", http.StatusServiceUnavailable)
rollbar.Error(rollbar.ERR, fmt.Errorf("unable to register stream: %#v", err))
util.CountWithData("mkstream.create.fail", 1, "error=%s", err)
return
}
util.Count("mkstream.create.success")
io.WriteString(w, string(uuid))
}
func (s *Server) createStream(w http.ResponseWriter, r *http.Request) {
registrar := broker.NewRedisRegistrar()
if err := registrar.Register(key(r)); err != nil {
http.Error(w, "Unable to create stream. Please try again.", http.StatusServiceUnavailable)
rollbar.Error(rollbar.ERR, fmt.Errorf("unable to register stream: %#v", err))
util.CountWithData("put.create.fail", 1, "error=%s", err)
return
}
util.Count("put.create.success")
w.WriteHeader(http.StatusCreated)
}
// Register registers the new channel
func (rr *RedisRegistrar) Register(channelName string) (err error) {
conn := redisPool.Get()
defer conn.Close()
channel := channel(channelName)
_, err = conn.Do("SETEX", channel.id(), redisChannelExpire, make([]byte, 0))
if err != nil {
util.CountWithData("RedisRegistrar.Register.error", 1, "error=%s", err)
return
}
return
}
// IsRegistered checks whether a channel name is registered
func (rr *RedisRegistrar) IsRegistered(channelName string) (registered bool) {
conn := redisPool.Get()
defer conn.Close()
channel := channel(channelName)
exists, err := redis.Bool(conn.Do("EXISTS", channel.id()))
if err != nil {
util.CountWithData("RedisRegistrar.IsRegistered.error", 1, "error=%s", err)
return false
}
return exists
}
func pub(w http.ResponseWriter, r *http.Request) {
if !util.StringSliceUtil(r.TransferEncoding).Contains("chunked") {
http.Error(w, "A chunked Transfer-Encoding header is required.", http.StatusBadRequest)
return
}
writer, err := broker.NewWriter(key(r))
if err != nil {
handleError(w, r, err)
return
}
defer writer.Close()
body := bufio.NewReader(r.Body)
defer r.Body.Close()
done := make(chan struct{})
go func() {
for {
select {
case <-done:
// Asynchronously upload the output to our defined storage backend.
go storeOutput(key(r), requestURI(r))
return
case <-time.After(*util.StorageInterval):
// Asynchronously upload the output to our defined storage backend.
go storeOutput(key(r), requestURI(r))
}
}
}()
_, err = io.Copy(writer, body)
if err == io.ErrUnexpectedEOF {
util.CountWithData("server.pub.read.eoferror", 1, "msg=\"%v\"", err.Error())
return
}
if err != nil {
log.Printf("%#v", err)
http.Error(w, "Unhandled error, please try again.", http.StatusInternalServerError)
rollbar.Error(rollbar.ERR, fmt.Errorf("unhandled error: %#v", err))
return
}
close(done)
}
func (r *reader) Read(p []byte) (n int, err error) {
if r.closed { // Don't read from a closed redigo connection
return 0, io.EOF
}
if n, err := r.replay(p); n > 0 || err != nil {
return n, err
}
switch msg := r.psc.Receive().(type) {
case redis.Message:
case redis.PMessage:
return r.read(msg, p)
case redis.Subscription:
case error:
util.CountWithData("RedisBroker.redisSubscribe.ReceiveError", 1, "err=%s", msg)
err = msg
return
}
return
}
func handleError(w http.ResponseWriter, r *http.Request, err error) {
switch err {
case broker.ErrNotRegistered, storage.ErrNoStorage, storage.ErrNotFound:
message := "Channel is not registered."
if r.Header.Get("Accept") == "text/ascii; version=feral" {
message = assets.HttpCatGone
}
http.Error(w, message, http.StatusNotFound)
case storage.ErrRange:
w.WriteHeader(http.StatusRequestedRangeNotSatisfiable)
case errNoContent:
// As indicated in the w3 spec[1] an SSE stream
// that's already done should return a `204 No Content`
// [1]: http://www.w3.org/TR/2012/WD-eventsource-20120426/
w.WriteHeader(http.StatusNoContent)
default:
util.CountWithData("server.handleError", 1, "error=%s", err.Error())
w.WriteHeader(http.StatusInternalServerError)
}
}