Recv reads one text frame from session.
()
| 196 | |
| 197 | // Recv reads one text frame from session. |
| 198 | func (w *WebsocketSession) Recv() (string, error) { |
| 199 | // Return previously received messages if there is any. |
| 200 | if len(w.messages) > 0 { |
| 201 | msg := w.messages[0] |
| 202 | w.messages = w.messages[1:] |
| 203 | return msg, nil |
| 204 | } |
| 205 | |
| 206 | read_frame: |
| 207 | if atomic.LoadInt32(&w.closed) == 1 { |
| 208 | return "", ErrSessionClosed |
| 209 | } |
| 210 | |
| 211 | // Read one SockJS frame. |
| 212 | _, buf, err := w.conn.ReadMessage() |
| 213 | if err != nil { |
| 214 | return "", err |
| 215 | } |
| 216 | |
| 217 | if len(buf) == 0 { |
| 218 | return "", errors.New("unexpected empty message") |
| 219 | } |
| 220 | |
| 221 | frameType := buf[0] |
| 222 | data := buf[1:] |
| 223 | |
| 224 | switch frameType { |
| 225 | case 'o': |
| 226 | w.setState(sockjs.SessionActive) |
| 227 | goto read_frame |
| 228 | case 'a': |
| 229 | var messages []string |
| 230 | err = json.Unmarshal(data, &messages) |
| 231 | if err != nil { |
| 232 | return "", err |
| 233 | } |
| 234 | w.messages = append(w.messages, messages...) |
| 235 | case 'm': |
| 236 | var message string |
| 237 | err = json.Unmarshal(data, &message) |
| 238 | if err != nil { |
| 239 | return "", err |
| 240 | } |
| 241 | w.messages = append(w.messages, message) |
| 242 | case 'c': |
| 243 | w.setState(sockjs.SessionClosed) |
| 244 | return "", ErrSessionClosed |
| 245 | case 'h': |
| 246 | // TODO handle heartbeat |
| 247 | goto read_frame |
| 248 | default: |
| 249 | return "", errors.New("invalid frame type") |
| 250 | } |
| 251 | |
| 252 | // Return first message in slice. |
| 253 | if len(w.messages) == 0 { |
| 254 | return "", errors.New("no message") |
| 255 | } |