官方实现

2023年06月11日

柏拉文

越努力，越幸运

一、实现

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1.1 packages/react-reconciler/src/ReactFiberClassComponent.js enqueueSetState()

enqueueSetState(inst: any, payload: any, callback) {
    const fiber = getInstance(inst);
    const lane = requestUpdateLane(fiber);

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

    const root = enqueueUpdate(fiber, update, lane);
    if (root !== null) {
      scheduleUpdateOnFiber(root, fiber, lane);
      entangleTransitions(root, fiber, lane);
    }

    if (__DEV__) {
      if (enableDebugTracing) {
        if (fiber.mode & DebugTracingMode) {
          const name = getComponentNameFromFiber(fiber) || 'Unknown';
          logStateUpdateScheduled(name, lane, payload);
        }
      }
    }

    if (enableSchedulingProfiler) {
      markStateUpdateScheduled(fiber, lane);
    }
}

二、测试

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