updateSuspenseOffscreenState() — react Function Reference

Source Code

packages/react-reconciler/src/ReactFiberBeginWork.js lines 2265–2295

function updateSuspenseOffscreenState(
  prevOffscreenState: OffscreenState,
  renderLanes: Lanes,
): OffscreenState {
  let cachePool: SpawnedCachePool | null = null;
  const prevCachePool: SpawnedCachePool | null = prevOffscreenState.cachePool;
  if (prevCachePool !== null) {
    const parentCache = isPrimaryRenderer
      ? CacheContext._currentValue
      : CacheContext._currentValue2;
    if (prevCachePool.parent !== parentCache) {
      // Detected a refresh in the parent. This overrides any previously
      // suspended cache.
      cachePool = {
        parent: parentCache,
        pool: parentCache,
      };
    } else {
      // We can reuse the cache from last time. The only thing that would have
      // overridden it is a parent refresh, which we checked for above.
      cachePool = prevCachePool;
    }
  } else {
    // If there's no previous cache pool, grab the current one.
    cachePool = getSuspendedCache();
  }
  return {
    baseLanes: mergeLanes(prevOffscreenState.baseLanes, renderLanes),
    cachePool,
  };
}