rv-chunk-upload-2.ts

// chunkUpload
 // uniformChunkRequest
 // partialChunkRequest
  // chunkRequestHelper

  // want to go over
   // 1 - uniform & partial upload (why there are 2 different functions)
   // 2 - use of `chunkRequestHelper` function to send headers & body (formData)
   // 3 - chunkStar & chunkEnd - how it's being calculated `chunkStart + CHUNK_SIZE > fileClone.size`

  async chunkUpload(directory: string, file: File,
    totalBytesUploaded?: number,
    permissionList?: Array<FSPermissions>,
    onUploadProgress?: (e: any) => void,
    cancelToken?: CancelToken): Promise<FSReport> {
    const fileName = file.name;
    // If there are totalBytesUploaded, divide by CHUNK_SIZE and * CHUNK_SIZE
    // to start from chunk size(s) done before retry/resume upload
    const chunkStart = totalBytesUploaded
      ? (Math.floor(totalBytesUploaded / CHUNK_SIZE) * CHUNK_SIZE)
      : 0;
    // If there are totalBytesUploaded, add CHUNK_SIZE to chunkStart calculation
    // to get the next chunkEnd after chunk size(s) done before retry/resume upload
    const chunkEnd = totalBytesUploaded
      ? ((Math.floor(chunkStart / CHUNK_SIZE) * CHUNK_SIZE) + CHUNK_SIZE)
      : CHUNK_SIZE;
    const path = `${directory}/${fileName}`;
    const fileObj = {
      path,
      file, // <File> File
      chunkStart,
      chunkEnd,
    };
    // uniformChunkRequest request
    return fs.uniformChunkRequest(fileObj,
      permissionList,
      onUploadProgress,
      cancelToken);
  }
    // IF the file size left < CHUNK_SIZE;
    // usually the very last request
    async partialChunkRequest(chunkRequestObj: ChunkRequest,
      permissionList?: Array<FSPermissions>,
      onUploadProgress?: (e:any) => void,
      cancelToken?: CancelToken): Promise<FSReport> {
      const { url, formData, options } = this.chunkRequestHelper(chunkRequestObj,
        permissionList, onUploadProgress, cancelToken);
      return new Promise((resolve, reject) => {
        // axios request
        axios.put(url, formData, options).then((response) => {
          if (response.status === 200) {
            resolve(response.data);
          }
        }).catch(err => reject(err));
      });
    }
  // recursive call
    // Slice the file size and
    // Upload the file with a CHUNK_SIZE;
    async uniformChunkRequest(chunkRequestObj: ChunkRequest,
      permissionList?: Array<FSPermissions>,
      onUploadProgress?: (e: any) => void,
      cancelToken?: CancelToken): Promise<FSReport> {
      const {
        path, file, chunkStart, chunkEnd,
      } = chunkRequestObj;
      const fileClone = file.slice();
      // Less than CHUNK_SIZE left
      if (chunkStart + CHUNK_SIZE > fileClone.size) {
        return this.partialChunkRequest({
          path,
          file,
          chunkStart,
          chunkEnd: file.slice().size,
        },
        permissionList, onUploadProgress, cancelToken);
      }
      const { url, formData, options } = this.chunkRequestHelper(chunkRequestObj,
        permissionList, onUploadProgress, cancelToken);
      // axios request
      await axios.put(url, formData, options);
      const updateRequestParams = {
        chunkStart: chunkEnd,
        chunkEnd: chunkEnd + CHUNK_SIZE,
      };
      return this.uniformChunkRequest({
        path,
        file,
        chunkStart: updateRequestParams.chunkStart,
        chunkEnd: updateRequestParams.chunkEnd,
      },
      permissionList, onUploadProgress, cancelToken);
    }

    // helper
    chunkRequestHelper({
      path, file, chunkStart, chunkEnd,
    }: ChunkRequest,
    permissionList?: Array<FSPermissions>,
    onUploadProgress?: (e: any) => void,
    cancelToken?: CancelToken): chunkRequestHelper {
      const uniqueId = path.split('/').join('');
      const formData = new FormData();
      const slicedPart = file.slice(chunkStart, chunkEnd);
      const fileClone = file.slice();
      const url = `${apiCarfs.url}/fs/${encodeURIComponent(encodeURIComponent(path))}`;
      if (permissionList && permissionList.length) {
        formData.set('permissions', JSON.stringify(permissionList));
      } else {
        formData.set('permissions', '[]');
      }
      formData.set('file', slicedPart);
      const options = {
        headers: {
          'Content-Type': 'multipart/form-data',
          'Content-Range': `bytes ${chunkStart}-${chunkEnd - 1}/${fileClone.size}`,
          'car-meta-chunk-file-id': `${uniqueId}`,
        },
        onUploadProgress,
        cancelToken,
      };
  
      return {
        url,
        formData,
        options,
      };
    }