React Fiber 异步调度器

导出的常量

1. 默认异步调度器

export const DefaultAsyncDispatcher: AsyncDispatcher = {
  getCacheForType,
  cacheSignal,
} as any;

if (__DEV__) {
  DefaultAsyncDispatcher.getOwner = (): null | Fiber => {
    return currentOwner;
  };
}

工具

1. 获取类型缓存

备注

• readContext() 由 ReactFiberNewContext#readContext 实现

function getCacheForType<T>(resourceType: () => T): T {
  const cache: Cache = readContext(CacheContext);
  let cacheForType: T | void = cache.data.get(resourceType) as any;
  if (cacheForType === undefined) {
    cacheForType = resourceType();
    cache.data.set(resourceType, cacheForType);
  }
  return cacheForType;
}

2. 缓存信号

备注

• readContext() 由 ReactFiberNewContext#readContext 实现

function cacheSignal(): null | AbortSignal {
  const cache: Cache = readContext(CacheContext);
  return cache.controller.signal;
}