openreplay/backend/internal/sessionender/ender.go
Alexander c6aac11cbf
Heuristics refactoring (#987)
* feat(backend): refactored heuristics service

* feat(backend): refactored db service (moved several events to heuristics)
2023-03-09 09:54:12 +01:00

94 lines
2.8 KiB
Go

package sessionender
import (
"log"
"time"
"openreplay/backend/pkg/messages"
"openreplay/backend/pkg/metrics/ender"
)
// EndedSessionHandler handler for ended sessions
type EndedSessionHandler func(sessionID uint64, timestamp uint64) bool
// session holds information about user's session live status
type session struct {
lastTimestamp int64
lastUpdate int64
lastUserTime uint64
isEnded bool
}
// SessionEnder updates timestamp of last message for each session
type SessionEnder struct {
timeout int64
sessions map[uint64]*session // map[sessionID]session
timeCtrl *timeController
}
func New(timeout int64, parts int) (*SessionEnder, error) {
return &SessionEnder{
timeout: timeout,
sessions: make(map[uint64]*session),
timeCtrl: NewTimeController(parts),
}, nil
}
// UpdateSession save timestamp for new sessions and update for existing sessions
func (se *SessionEnder) UpdateSession(msg messages.Message) {
var (
sessionID = msg.Meta().SessionID()
batchTimestamp = msg.Meta().Batch().Timestamp()
msgTimestamp = msg.Meta().Timestamp
localTimestamp = time.Now().UnixMilli()
)
if batchTimestamp == 0 {
log.Printf("got empty timestamp for sessionID: %d", sessionID)
return
}
se.timeCtrl.UpdateTime(sessionID, batchTimestamp)
sess, ok := se.sessions[sessionID]
if !ok {
// Register new session
se.sessions[sessionID] = &session{
lastTimestamp: batchTimestamp, // timestamp from message broker
lastUpdate: localTimestamp, // local timestamp
lastUserTime: msgTimestamp, // last timestamp from user's machine
isEnded: false,
}
ender.IncreaseActiveSessions()
ender.IncreaseTotalSessions()
return
}
// Keep the highest user's timestamp for correct session duration value
if msgTimestamp > sess.lastUserTime {
sess.lastUserTime = msgTimestamp
}
// Keep information about the latest message for generating sessionEnd trigger
if batchTimestamp > sess.lastTimestamp {
sess.lastTimestamp = batchTimestamp
sess.lastUpdate = localTimestamp
sess.isEnded = false
}
}
// HandleEndedSessions runs handler for each ended session and delete information about session in successful case
func (se *SessionEnder) HandleEndedSessions(handler EndedSessionHandler) {
currTime := time.Now().UnixMilli()
allSessions, removedSessions := len(se.sessions), 0
for sessID, sess := range se.sessions {
if sess.isEnded || (se.timeCtrl.LastTimestamp(sessID)-sess.lastTimestamp > se.timeout) ||
(currTime-sess.lastUpdate > se.timeout) {
sess.isEnded = true
if handler(sessID, sess.lastUserTime) {
delete(se.sessions, sessID)
ender.DecreaseActiveSessions()
ender.IncreaseClosedSessions()
removedSessions++
} else {
log.Printf("sessID: %d, userTime: %d", sessID, sess.lastUserTime)
}
}
}
log.Printf("Removed %d of %d sessions", removedSessions, allSessions)
}