parsUrls.gs

function test_parse() {
  var file = SpreadsheetApp.getActive();
  var sheet = file.getSheetByName('Sheet1');          // change
  var sets = {
    rangeParse: sheet.getRange('L2:L16429'),          // change
    rangeResult: sheet.getRange("M2"),                // change
    func_parse: parseOkkoFilmToGetHorizontalPoster_   // change / create your function
  };
  parseUrls_(sets);
}


// Stage [ 0 ]. Define function for parsing conent text
function parseOkkoFilmToGetHorizontalPoster_(text) {
  var re = new RegExp("v2\/([^?]*)\?");
  var found = text.match(re);
  if (!found) { return '-'; }
  return found[0]; 
}


// Stage [ 1 ]. Get All requests to complete as 2d array (column) 
// sets:
// {
//   rangeParse,
//   rangeResult
//   func_parse
// }
function parseUrls_(sets) {
  var limit = 50; // parse by 50 urls
  var res = []; // 2d-array
  //
  var column = sets.rangeParse.getValues();
  var rto = sets.rangeResult.offset(0, 0, 1, 1);
  //
  var t = new Date();
  // 
  var requests = [], url, datares = [];
  for (var i = 0; i < column.length; i++) {
    url = column[i][0];
    if (!url || url === '#N/A') { url = 'https://max-makhrov.github.io/'; }
    var request = {
      url: url,
      muteHttpExceptions: true
    }
    requests.push(request);
    if ((i % 50) === 0 && i !== 0) {
      datares = parseRequestsTo2DResult_(requests, sets.func_parse);
      rto.offset(i - datares.length + 1, 0, datares.length).setValues(datares);
      requests = [];
    }
  }
  if (requests.length > 0) {
    datares = parseRequestsTo2DResult_(requests, sets.func_parse);
    rto.offset(i - datares.length, 0, datares.length).setValues(datares);
  }
  console.log(new Date() - t)

}


// Stage [ 2 ]. Parse requests
function parseRequestsTo2DResult_(requests, func) {
  var responses = UrlFetchApp.fetchAll(requests);
   var res0 = responses.map(function (e) { return e.getContentText() });
   var res = []; // 2d array
   for (var i = 0; i < res0.length; i++) {
     res.push([func(res0[i])]);
   }
   return res;
}