react hook,effect等结构

hook相关结构

  const hook: Hook = {
    memoizedState: null,
    baseState: null,
    baseQueue: null,
    queue: null,
    next: null,
  };
  
  const queue = (hook.queue = {
    pending: null,
    dispatch: null,
    lastRenderedReducer: basicStateReducer,
    lastRenderedState: (initialState: any),
  });
  
   type UpdateQueue<S, A> = {|
	  pending: Update<S, A> | null,
	  dispatch: (A => mixed) | null,
	  lastRenderedReducer: ((S, A) => S) | null,
	  lastRenderedState: S | null,
	|};
  
   const update: Update<S, A> = {
    lane,
    action,
    eagerReducer: null,
    eagerState: null,
    next: (null: any),
  };
  
   const action = update.action;
          newState = reducer(newState, action);

effect相关结构

export type Effect = {|
  tag: HookFlags,
  create: () => (() => void) | void,
  destroy: (() => void) | void,
  deps: Array<mixed> | null,
  next: Effect,
|};

componentUpdateQueue.lastEffect = effect.next = effect;

  hook.memoizedState = pushEffect(
    HookHasEffect | hookFlags,
    create,
    undefined,
    nextDeps,
  );

组件的setState相关结构

  enqueueSetState(inst, payload, callback) {
    const fiber = getInstance(inst);
    const eventTime = requestEventTime();
    const lane = requestUpdateLane(fiber);

    const update = createUpdate(eventTime, lane);
    update.payload = payload;
    if (callback !== undefined && callback !== null) {
      if (__DEV__) {
        warnOnInvalidCallback(callback, 'setState');
      }
      update.callback = callback;
    }

    enqueueUpdate(fiber, update);
    scheduleUpdateOnFiber(fiber, lane, eventTime);
}
	
export function createUpdate(eventTime: number, lane: Lane): Update<*> {
  const update: Update<*> = {
	eventTime,
	lane,

	tag: UpdateState,
	payload: null,
	callback: null,

	next: null,
  };
  return update;
}

export function enqueueUpdate<State>(fiber: Fiber, update: Update<State>) {
  const updateQueue = fiber.updateQueue;
  if (updateQueue === null) {
    // Only occurs if the fiber has been unmounted.
    return;
  }

  const sharedQueue: SharedQueue<State> = (updateQueue: any).shared;
  const pending = sharedQueue.pending;
  if (pending === null) {
    // This is the first update. Create a circular list.
    update.next = update;
  } else {
    update.next = pending.next;
    pending.next = update;
  }
  sharedQueue.pending = update;
}

 do {
        var updateLane = update.lane;
        var updateEventTime = update.eventTime;

        if (!isSubsetOfLanes(renderLanes, updateLane)) {
          // Priority is insufficient. Skip this update. If this is the first
          // skipped update, the previous update/state is the new base
          // update/state.
          var clone = {
            eventTime: updateEventTime,
            lane: updateLane,
            tag: update.tag,
            payload: update.payload,
            callback: update.callback,
            next: null
          };

          if (newLastBaseUpdate === null) {
            newFirstBaseUpdate = newLastBaseUpdate = clone;
            newBaseState = newState;
          } else {
            newLastBaseUpdate = newLastBaseUpdate.next = clone;
          } // Update the remaining priority in the queue.


          newLanes = mergeLanes(newLanes, updateLane);
        } else {
          // This update does have sufficient priority.
          if (newLastBaseUpdate !== null) {
            var _clone = {
              eventTime: updateEventTime,
              // This update is going to be committed so we never want uncommit
              // it. Using NoLane works because 0 is a subset of all bitmasks, so
              // this will never be skipped by the check above.
              lane: NoLane,
              tag: update.tag,
              payload: update.payload,
              callback: update.callback,
              next: null
            };
            newLastBaseUpdate = newLastBaseUpdate.next = _clone;
          } // Process this update.


          newState = getStateFromUpdate(workInProgress, queue, update, newState, props, instance);
          var callback = update.callback;

          if (callback !== null) {
            workInProgress.flags |= Callback;
            var effects = queue.effects;

            if (effects === null) {
              queue.effects = [update];
            } else {
              effects.push(update);
            }
          }
        }

        update = update.next;

        if (update === null) {
          pendingQueue = queue.shared.pending;

          if (pendingQueue === null) {
            break;
          } else {
            // An update was scheduled from inside a reducer. Add the new
            // pending updates to the end of the list and keep processing.
            var _lastPendingUpdate = pendingQueue; // Intentionally unsound. Pending updates form a circular list, but we
            // unravel them when transferring them to the base queue.

            var _firstPendingUpdate = _lastPendingUpdate.next;
            _lastPendingUpdate.next = null;
            update = _firstPendingUpdate;
            queue.lastBaseUpdate = _lastPendingUpdate;
            queue.shared.pending = null;
          }
        }
      } while (true);