angular-file-md5.js

(function(){
  'use strict';

  angular.module('ljungmann.fileMd5', [])
  .provider('fileMd5Service', [function() {

    var settings = {
      chunkSize: 2097152 // 2 MB
    };

    this.configure = function(additionalSettings) {
      angular.extend(settings, additionalSettings);

      return this;
    };

    this.$get = ['$q', function($q) {

      return {
        md5: function(file) {
          var slicer = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice;
          var currentChunk = 0;
          var chunks = Math.ceil(file.size / settings.chunkSize);

          var spark = new SparkMD5.ArrayBuffer();

          var deferred = $q.defer();
          var promise = deferred.promise;

          var onLoadFn = function(event) {
            spark.append(event.target.result);

            deferred.notify({
              loaded: currentChunk * settings.chunkSize + event.loaded,
              total: file.size
            });

            currentChunk++;
            if (currentChunk < chunks) {
              loadData();
            } else {
              var md5sum = spark.end();
              deferred.resolve(md5sum);
            }
          };

          var onErrorFn = function (error) {
            deferred.reject(error);
          };

          var loadData = function() {
            var fileReader = new FileReader();
            fileReader.onload = onLoadFn;
            fileReader.onerror = onErrorFn;

            var start = currentChunk * settings.chunkSize;
            var end = ((start + settings.chunkSize) >= file.size) ? file.size : start + settings.chunkSize;

            fileReader.readAsArrayBuffer(slicer.call(file, start, end));
          };

          promise.success = function(fn) {
            promise.then(function(md5sum) {
              fn(md5sum);
            });

            return promise;
          };

          promise.error = function(fn) {
            promise.then(null, function(error) {
              fn(error);
            });

            return promise;
          };

          promise.progress = function(fn) {
            promise.then(null, null, function(stats) {
              fn(stats);
            });

            return promise;
          };

          loadData();

          return promise;
        }
      };

    }];

  }]);

})();