openreplay/backend/internal/sessionender/ender.go
2022-06-07 13:48:10 +02:00

89 lines
2.6 KiB
Go

package sessionender
import (
"context"
"fmt"
"go.opentelemetry.io/otel/metric/instrument/syncfloat64"
"log"
"openreplay/backend/pkg/monitoring"
"time"
)
// EndedSessionHandler handler for ended sessions
type EndedSessionHandler func(sessionID uint64, timestamp int64) bool
// session holds information about user's session live status
type session struct {
lastTimestamp int64
isEnded bool
}
// SessionEnder updates timestamp of last message for each session
type SessionEnder struct {
timeout int64
sessions map[uint64]*session // map[sessionID]session
activeSessions syncfloat64.UpDownCounter
totalSessions syncfloat64.Counter
}
func New(metrics *monitoring.Metrics, timeout int64) (*SessionEnder, error) {
if metrics == nil {
return nil, fmt.Errorf("metrics module is empty")
}
activeSessions, err := metrics.RegisterUpDownCounter("sessions_active")
if err != nil {
return nil, fmt.Errorf("can't register session.active metric: %s", err)
}
totalSessions, err := metrics.RegisterCounter("sessions_total")
if err != nil {
return nil, fmt.Errorf("can't register session.total metric: %s", err)
}
return &SessionEnder{
timeout: timeout,
sessions: make(map[uint64]*session),
activeSessions: activeSessions,
totalSessions: totalSessions,
}, nil
}
// UpdateSession save timestamp for new sessions and update for existing sessions
func (se *SessionEnder) UpdateSession(sessionID, timestamp uint64) {
currTS := int64(timestamp)
if currTS == 0 {
log.Printf("got empty timestamp for sessionID: %d", sessionID)
return
}
sess, ok := se.sessions[sessionID]
if !ok {
se.sessions[sessionID] = &session{
lastTimestamp: currTS,
isEnded: false,
}
log.Printf("added new session: %d", sessionID)
se.activeSessions.Add(context.Background(), 1)
se.totalSessions.Add(context.Background(), 1)
return
}
if currTS > sess.lastTimestamp {
sess.lastTimestamp = currTS
sess.isEnded = false
}
}
// HandleEndedSessions runs handler for each ended session and delete information about session in successful case
func (se *SessionEnder) HandleEndedSessions(handler EndedSessionHandler) {
deadLine := time.Now().UnixMilli() - se.timeout
allSessions, removedSessions := len(se.sessions), 0
for sessID, sess := range se.sessions {
if sess.isEnded || sess.lastTimestamp < deadLine {
sess.isEnded = true
if handler(sessID, sess.lastTimestamp) {
delete(se.sessions, sessID)
se.activeSessions.Add(context.Background(), -1)
removedSessions++
}
}
}
log.Printf("Removed %d of %d sessions", removedSessions, allSessions)
}