(state *SessionState)
| 27 | SessionRead(sessionId string) (*SessionState, error) |
| 28 | SessionExist(sessionId string) bool |
| 29 | SessionUpdate(state *SessionState) error |
| 30 | SessionRemove(sessionId string) error |
| 31 | SessionCount() int // get all active session length |
| 32 | SessionGC() int // gc session and return out of date state num |
no outgoing calls