React DOM fizz instruction set external runtime

执行了全局副作用。

// This is a string so Closure's advanced compilation mode doesn't mangle it.
// 这是一个字符串，因此 Closure 的高级编译模式不会破坏它。
// These will be renamed to local references by the external-runtime-plugin.
// 这些将由 external-runtime-plugin 重命名为本地引用。
window['$RM'] = new Map();
window['$RB'] = [];
window['$RX'] = clientRenderBoundary;
window['$RV'] = revealCompletedBoundariesWithViewTransitions.bind(
  null,
  revealCompletedBoundaries,
);
window['$RC'] = completeBoundary;
window['$RR'] = completeBoundaryWithStyles;
window['$RS'] = completeSegment;

listenToFormSubmissionsForReplaying();

// Track the paint time of the shell.
// 跟踪外壳的绘制时间。
const entries = performance.getEntriesByType
  ? performance.getEntriesByType('paint')
  : [];
if (entries.length > 0) {
  // We might have already painted before this external runtime loaded. In that case we
  // try to get the first paint from the performance metrics to avoid delaying further
  // than necessary.
  // 在此外部运行时加载之前，我们可能已经进行了绘制。在这种情况下，我们尝试从性能指标中获取第一次绘制，
  // 以避免不必要的进一步延迟。
  window['$RT'] = entries[0].startTime;
} else {
  // Otherwise we wait for the next rAF for it.
  // 否则我们等待下一个 rAF（requestAnimationFrame） 执行它。
  requestAnimationFrame(() => {
    window['$RT'] = performance.now();
  });
}