feat: add _experimental_longtaskNoStartSession flag

packages/web/src/session.ts

@@ -39,9 +39,10 @@ import { cookieStore, findCookieValue, generateId, isIframe } from './utils'
     with setting cookies, checking for inactivity, etc.
 */
 
-const MaxSessionAgeMillis = 4 * 60 * 60 * 1000
-const InactivityTimeoutSeconds = 15 * 60
-const PeriodicCheckSeconds = 60
+const MaxSessionAgeSeconds = 4 * 60 * 60
+const MaxSessionAgeMillis = MaxSessionAgeSeconds * 1000
+const InactivityTimeoutMillis = 15 * 60 * 1000
+
 export const COOKIE_NAME = '_splunk_rum_sid'
 
 export type SessionIdType = string
@@ -59,7 +60,18 @@ function pastMaxAge(startTime: number): boolean {
 	return startTime > now || now > startTime + MaxSessionAgeMillis
 }
 
-export function parseCookieToSessionState(): { id: string; startTime: number } | undefined {
+function pastExpirationTime(expirationTime: number): boolean {
+	const now = Date.now()
+	return expirationTime < now + InactivityTimeoutMillis
+}
+
+interface CookieState {
+	expirationTime?: number
+	id: string
+	startTime: number
+}
+
+export function parseCookieToSessionState(): CookieState | undefined {
 	const rawValue = findCookieValue(COOKIE_NAME)
 	if (!rawValue) {
 		return undefined
@@ -70,7 +82,7 @@ export function parseCookieToSessionState(): { id: string; startTime: number } |
 		return undefined
 	}
 
-	let ss: { id: string; startTime: number } | undefined = undefined
+	let ss: CookieState | undefined = undefined
 	try {
 		ss = JSON.parse(decoded)
 	} catch {
@@ -91,25 +103,30 @@ export function parseCookieToSessionState(): { id: string; startTime: number } |
 		return undefined
 	}
 
+	if ('expirationTime' in ss && typeof ss.expirationTime === 'number' && pastExpirationTime(ss.expirationTime)) {
+		return undefined
+	}
+
 	return ss
 }
 
-function newSessionState() {
+function newSessionState(): CookieState {
 	return {
 		id: generateId(128),
 		startTime: Date.now(),
+		expirationTime: Date.now() + InactivityTimeoutMillis,
 	}
 }
 
-function renewCookieTimeout(sessionState) {
+function updateCookie(sessionState: CookieState) {
 	if (pastMaxAge(sessionState.startTime)) {
 		// safety valve
 		return
 	}
 
 	const cookieValue = encodeURIComponent(JSON.stringify(sessionState))
 	const domain = cookieDomain ? `domain=${cookieDomain};` : ''
-	let cookie = COOKIE_NAME + '=' + cookieValue + '; path=/;' + domain + 'max-age=' + InactivityTimeoutSeconds
+	let cookie = COOKIE_NAME + '=' + cookieValue + '; path=/;' + domain + 'max-age=' + MaxSessionAgeSeconds
 
 	if (isIframe()) {
 		cookie += ';SameSite=None; Secure'
@@ -141,7 +158,8 @@ export function updateSessionStatus(): void {
 	eventTarget?.emit('session-changed', { sessionId: rumSessionId })
 
 	if (recentActivity) {
-		renewCookieTimeout(sessionState)
+		sessionState.expirationTime = Date.now() + InactivityTimeoutMillis
+		updateCookie(sessionState)
 	}
 
 	recentActivity = false
@@ -151,15 +169,21 @@ function hasNativeSessionId(): boolean {
 	return typeof window !== 'undefined' && window['SplunkRumNative'] && window['SplunkRumNative'].getNativeSessionId
 }
 
-class ActivitySpanProcessor implements SpanProcessor {
+class SessionSpanProcessor implements SpanProcessor {
+	constructor(private readonly allSpansAreActivity: boolean) {}
+
 	forceFlush(): Promise<void> {
 		return Promise.resolve()
 	}
 
 	onEnd(): void {}
 
 	onStart(): void {
-		markActivity()
+		if (this.allSpansAreActivity) {
+			markActivity()
+		}
+
+		updateSessionStatus()
 	}
 
 	shutdown(): Promise<void> {
@@ -194,17 +218,13 @@ export function initSessionTracking(
 	eventTarget = newEventTarget
 
 	ACTIVITY_EVENTS.forEach((type) => document.addEventListener(type, markActivity, { capture: true, passive: true }))
-	if (allSpansAreActivity) {
-		provider.addSpanProcessor(new ActivitySpanProcessor())
-	}
+	provider.addSpanProcessor(new SessionSpanProcessor(allSpansAreActivity))
 
 	updateSessionStatus()
-	const intervalHandle = setInterval(() => updateSessionStatus(), PeriodicCheckSeconds * 1000)
 
 	return {
 		deinit: () => {
 			ACTIVITY_EVENTS.forEach((type) => document.removeEventListener(type, markActivity))
-			clearInterval(intervalHandle)
 			rumSessionId = undefined
 			eventTarget = undefined
 		},