Function getPostponedState

packages/react-server/src/ReactFizzServer.js:6374–6415

(request: Request)

// Returns the state of a postponed request or null if nothing was postponed.
export function getPostponedState(request: Request): null | PostponedState {
  const trackedPostpones = request.trackedPostpones;
  if (
    trackedPostpones === null ||
    (trackedPostpones.rootNodes.length === 0 &&
      trackedPostpones.rootSlots === null)
  ) {
    // Reset. Let the flushing behave as if we completed the whole document.
    request.trackedPostpones = null;
    return null;
  }
  let replaySlots: ResumeSlots;
  let nextSegmentId: number;
  if (
    request.completedRootSegment !== null &&
    // The Root postponed
    (request.completedRootSegment.status === POSTPONED ||
      // Or the Preamble was not available
      request.completedPreambleSegments === null)
  ) {
    nextSegmentId = 0;
    // We need to ensure that on resume we retry the root. We use a number
    // type for the replaySlots to signify this (see resumeRequest).
    // The value -1 represents an unassigned ID but is not functionally meaningful
    // for resuming at the root.
    replaySlots = -1;
    // We either postponed the root or we did not have a preamble to flush
    resetResumableState(request.resumableState, request.renderState);
  } else {
    nextSegmentId = request.nextSegmentId;
    replaySlots = trackedPostpones.rootSlots;
    completeResumableState(request.resumableState);
  }
  return {
    nextSegmentId,
    rootFormatContext: request.rootFormatContext,
    progressiveChunkSize: request.progressiveChunkSize,
    resumableState: request.resumableState,
    replayNodes: trackedPostpones.rootNodes,
    replaySlots,
  };
}