Function logStartupPerf

src/utils/startupProfiler.ts:159–194

()

 * Only logs if this session was sampled at startup.
 */
export function logStartupPerf(): void {
  // Only log if we were sampled (decision made at module load)
  if (!STATSIG_LOGGING_SAMPLED) return

  const perf = getPerformance()
  const marks = perf.getEntriesByType('mark')
  if (marks.length === 0) return

  // Build checkpoint lookup
  const checkpointTimes = new Map<string, number>()
  for (const mark of marks) {
    checkpointTimes.set(mark.name, mark.startTime)
  }

  // Compute phase durations
  const metadata: Record<string, number | undefined> = {}

  for (const [phaseName, [startCheckpoint, endCheckpoint]] of Object.entries(
    PHASE_DEFINITIONS,
  )) {
    const startTime = checkpointTimes.get(startCheckpoint)
    const endTime = checkpointTimes.get(endCheckpoint)

    if (startTime !== undefined && endTime !== undefined) {
      metadata[`${phaseName}_ms`] = Math.round(endTime - startTime)
    }
  }

  // Add checkpoint count for debugging
  metadata.checkpoint_count = marks.length

  logEvent(
    'tengu_startup_perf',
    metadata as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
  )
}