upload_sdk/utils.js

import { SparkMD5 } from 'spark-md5'

export function get_filemd5sum(ofile) {
  var file = ofile;
  var tmp_md5;
  var blobSlice = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice,
      // file = this.files[0],
      chunkSize = 8097152, // Read in chunks of 2MB
      chunks = Math.ceil(file.size / chunkSize),
      currentChunk = 0,
      spark = new SparkMD5.ArrayBuffer(),
      fileReader = new FileReader();

  fileReader.onload = function(e) {
      spark.append(e.target.result); // Append array buffer
      currentChunk++;

      if (currentChunk < chunks) {
          loadNext();
      } else {
          tmp_md5 = spark.end();
          return tmp_md5
      }
  };

  fileReader.onerror = function() {
      console.warn('oops, something went wrong.');
  };

  function loadNext() {
      var start = currentChunk * chunkSize,
          end = ((start + chunkSize) >= file.size) ? file.size : start + chunkSize;
      fileReader.readAsArrayBuffer(blobSlice.call(file, start, end));
  }
  loadNext();
}

export function getBase64(file) {
    var reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = function (e) { 
        return this.result.substring(this.result.indexOf(',')+1);
    }
}