Function initializePerfettoTracing

src/utils/telemetry/perfettoTracing.ts:253–335

()

 * Call this early in the application lifecycle
 */
export function initializePerfettoTracing(): void {
  const envValue = process.env.CLAUDE_CODE_PERFETTO_TRACE
  logForDebugging(
    `[Perfetto] initializePerfettoTracing called, env value: ${envValue}`,
  )

  // Wrap in feature() for dead code elimination - entire block removed from external builds
  if (feature('PERFETTO_TRACING')) {
    if (!envValue || isEnvDefinedFalsy(envValue)) {
      logForDebugging(
        '[Perfetto] Tracing disabled (env var not set or disabled)',
      )
      return
    }

    isEnabled = true
    startTimeMs = Date.now()

    // Determine trace file path
    if (isEnvTruthy(envValue)) {
      const tracesDir = join(getClaudeConfigHomeDir(), 'traces')
      tracePath = join(tracesDir, `trace-${getSessionId()}.json`)
    } else {
      // Use the provided path
      tracePath = envValue
    }

    logForDebugging(
      `[Perfetto] Tracing enabled, will write to: ${tracePath}, isEnabled=${isEnabled}`,
    )

    // Start periodic full-trace write if CLAUDE_CODE_PERFETTO_WRITE_INTERVAL_S is a positive integer
    const intervalSec = parseInt(
      process.env.CLAUDE_CODE_PERFETTO_WRITE_INTERVAL_S ?? '',
      10,
    )
    if (intervalSec > 0) {
      writeIntervalId = setInterval(() => {
        void periodicWrite()
      }, intervalSec * 1000)
      // Don't let the interval keep the process alive on its own
      if (writeIntervalId.unref) writeIntervalId.unref()
      logForDebugging(
        `[Perfetto] Periodic write enabled, interval: ${intervalSec}s`,
      )
    }

    // Start stale span cleanup interval
    staleSpanCleanupId = setInterval(() => {
      evictStaleSpans()
      evictOldestEvents()
    }, STALE_SPAN_CLEANUP_INTERVAL_MS)
    if (staleSpanCleanupId.unref) staleSpanCleanupId.unref()

    // Register cleanup to write final trace on exit
    registerCleanup(async () => {
      logForDebugging('[Perfetto] Cleanup callback invoked')
      await writePerfettoTrace()