Method _writeFileFromRoot

src/fsOnedrive.ts:919–1025

(
    key: string,
    content: ArrayBuffer,
    mtime: number,
    ctime: number,
    origKey: string,
    emptyFile: "skip" | "error"
  )

  }

  async _writeFileFromRoot(
    key: string,
    content: ArrayBuffer,
    mtime: number,
    ctime: number,
    origKey: string,
    emptyFile: "skip" | "error"
  ): Promise<Entity> {
    if (content.byteLength === 0) {
      if (emptyFile === "error") {
        throw Error(
          `${origKey}: Empty file is not allowed in OneDrive, and please write something in it.`
        );
      } else {
        return {
          key: origKey,
          keyRaw: origKey,
          mtimeSvr: mtime,
          mtimeCli: mtime,
          ctimeCli: ctime,
          size: 0,
          sizeRaw: 0,
          synthesizedFile: true,
          // hash: ?? // TODO
        };
      }
    }

    const ctimeStr = new Date(ctime).toISOString();
    const mtimeStr = new Date(mtime).toISOString();

    // no need to create parent folders firstly, cool!

    // hard code range size
    const MIN_UNIT = 327680; // bytes in msft doc, about 0.32768 MB
    const RANGE_SIZE = MIN_UNIT * 20; // about 6.5536 MB
    const DIRECT_UPLOAD_MAX_SIZE = 1000 * 1000 * 4; // 4 Megabyte

    if (content.byteLength < DIRECT_UPLOAD_MAX_SIZE) {
      // directly using put!
      await this._putArrayBuffer(
        `${key}:/content?${new URLSearchParams({
          "@microsoft.graph.conflictBehavior": "replace",
        })}`,
        content
      );
      if (mtime !== 0 && ctime !== 0) {
        await this._patchJson(key, {
          fileSystemInfo: {
            lastModifiedDateTime: mtimeStr,
            createdDateTime: ctimeStr,
          } as FileSystemInfo,
        });
      }
    } else {
      // upload large files!
      // ref: https://docs.microsoft.com/en-us/onedrive/developer/rest-api/api/driveitem_createuploadsession?view=odsp-graph-online