Function importFile

packages/react-devtools-timeline/src/timelineCache.js:50–110

(file: File)

}

export function importFile(file: File): TimelineData | Error {
  const fileName = file.name;
  let record = fileNameToProfilerDataMap.get(fileName);

  if (!record) {
    const callbacks = new Set<(value: any) => mixed>();
    const rejectCallbacks = new Set<(reason: mixed) => mixed>();
    const thenable: Thenable<TimelineData> = {
      status: 'pending',
      value: null,
      reason: null,
      then(callback: (value: any) => mixed, reject: (error: mixed) => mixed) {
        callbacks.add(callback);
        rejectCallbacks.add(reject);
      },

      // Optional property used by Timeline:
      displayName: `Importing file "${fileName}"`,
    };

    const wake = () => {
      // This assumes they won't throw.
      callbacks.forEach(callback => callback((thenable: any).value));
      callbacks.clear();
      rejectCallbacks.clear();
    };
    const wakeRejections = () => {
      // This assumes they won't throw.
      rejectCallbacks.forEach(callback => callback((thenable: any).reason));
      rejectCallbacks.clear();
      callbacks.clear();
    };

    record = thenable;

    importFileWorker(file).then(data => {
      switch (data.status) {
        case 'SUCCESS':
          const fulfilledThenable: FulfilledThenable<TimelineData> =
            (thenable: any);
          fulfilledThenable.status = 'fulfilled';
          fulfilledThenable.value = data.processedData;
          wake();
          break;
        case 'INVALID_PROFILE_ERROR':
        case 'UNEXPECTED_ERROR':
          const rejectedThenable: RejectedThenable<TimelineData> =
            (thenable: any);
          rejectedThenable.status = 'rejected';
          rejectedThenable.reason = data.error;
          wakeRejections();
          break;
      }
    });

    fileNameToProfilerDataMap.set(fileName, record);
  }