pushRootMarkerInstance() — react Function Reference

Source Code

packages/react-reconciler/src/ReactFiberTracingMarkerComponent.js lines 203–240

export function pushRootMarkerInstance(workInProgress: Fiber): void {
  if (enableTransitionTracing) {
    // On the root, every transition gets mapped to it's own map of
    // suspense boundaries. The transition is marked as complete when
    // the suspense boundaries map is empty. We do this because every
    // transition completes at different times and depends on different
    // suspense boundaries to complete. We store all the transitions
    // along with its map of suspense boundaries in the root incomplete
    // transitions map. Each entry in this map functions like a tracing
    // marker does, so we can push it onto the marker instance stack
    const transitions = getWorkInProgressTransitions();
    const root: FiberRoot = workInProgress.stateNode;

    if (transitions !== null) {
      transitions.forEach(transition => {
        if (!root.incompleteTransitions.has(transition)) {
          const markerInstance: TracingMarkerInstance = {
            tag: TransitionRoot,
            transitions: new Set([transition]),
            pendingBoundaries: null,
            aborts: null,
            name: null,
          };
          root.incompleteTransitions.set(transition, markerInstance);
        }
      });
    }

    const markerInstances = [];
    // For ever transition on the suspense boundary, we push the transition
    // along with its map of pending suspense boundaries onto the marker
    // instance stack.
    root.incompleteTransitions.forEach(markerInstance => {
      markerInstances.push(markerInstance);
    });
    push(markerInstanceStack, markerInstances, workInProgress);
  }
}