openreplay/backend/pkg/handlers/web/domDrop.go
2022-06-06 14:13:24 +02:00

55 lines
1.1 KiB
Go

package web
import (
. "openreplay/backend/pkg/messages"
)
/*
Handler name: DomDrop
Input events: CreateElementNode,
CreateTextNode,
RemoveNode
Output event: DOMDrop
*/
const DROP_WINDOW = 200 //ms
const CRITICAL_COUNT = 1 // Our login page contains 20. But on crush it removes only roots (1-3 nodes).
// TODO: smart detection (making whole DOM tree would eat all memory)
type domDropDetector struct {
removedCount int
lastDropTimestamp uint64
}
func (dd *domDropDetector) reset() {
dd.removedCount = 0
dd.lastDropTimestamp = 0
}
func (dd *domDropDetector) Handle(message Message, _ uint64, timestamp uint64) Message {
switch message.(type) {
case *CreateElementNode,
*CreateTextNode:
dd.removedCount = 0
dd.lastDropTimestamp = 0
case *RemoveNode:
if dd.lastDropTimestamp+DROP_WINDOW > timestamp {
dd.removedCount += 1
} else {
dd.removedCount = 1
}
dd.lastDropTimestamp = timestamp
}
return nil
}
func (dd *domDropDetector) Build() Message {
defer dd.reset()
if dd.removedCount >= CRITICAL_COUNT {
domDrop := &DOMDrop{
Timestamp: dd.lastDropTimestamp,
}
return domDrop
}
return nil
}