gistfile1.txt

dio.ID3Finder = function () {};

dio.ID3Finder._songMap = {};

dio.ID3Finder.getInfoForSong = function (song, callback) {

  var req;

  if (song.url in dio.ID3Finder._songMap) {
    callback();
    return;
  }
  req = new XMLHttpRequest();
  req.open('GET', song.url, true);
  req.onreadystatechange = dio.ID3Finder._handleInfoForSong.bind(
    dio.ID3Finder,
    song,
    req,
    callback
  );
  req.responseType = 'arraybuffer';
  req.send(null);
};

dio.ID3Finder._handleInfoForSong = function (song, req, callback) {

  var data, subset;

  if (req.readyState === 4 && req.status === 200) {
    data = req.response;
    //Search for ID3v2.*
    if (dio.ID3Finder.getString(data, 3, 0) === 'ID3') {
      dio.ID3Finder.getID3v2Info(data, callback);
      return;
    }
    //Search for ID3v1
    subset = data.slice(data.length - 128);
    if (dio.ID3Finder.getString(subset, 3, 0) === 'TAG') {
      dio.ID3Finder.getID3v1Info(subset, callback);
    }
    return;
  } else {
    console.log('Loading...');
  }
};

dio.ID3Finder.getString = function (buffer, length, offset) {

    var ints, stringArray, i;

    stringArray = [];
    ints = new Int8Array(buffer, offset, length);
    for (i = 0; i < length; ++i) {
      stringArray[i] = ints[i];
    }
    return String.fromCharCode.apply(null, stringArray);
};