Optimising fullcalendar with meteor for large data - fullcalendar

Question

I'm using an auto-run block where I re-execute the same mongo with a few session variables ! loop over those doc , construct an array of events then I call the addEventSource and refetchResources function which are pretty expensive computationally ! the fullcalendar becomes slow the more data ! on every action the auto-run block is rerun ! what in your in your opinion can be done to speed things up ? I thought about only re-rendering the delta elements but this doesn't cover the deletion and update .
calendar = $('#calendar').fullCalendar({
schedulerLicenseKey: Meteor.settings.public.fullCalendarLicenseKey,
now: new Date(),
editable: true, // enable draggable events
droppable: true, // this allows things to be dropped onto the calendar
aspectRatio: 1.8,
timezone:'local',
disableDragging: true,
displayEventTime: false,
selectable:true,
allDaySlot:true,
slotDuration:'24:00',
lazyFetching:true,
resourceLabelText: 'Employees',
nextDayThreshold:"12:00",
resources: function(callback) {
var tmp_obj = { usersSorting : { } };
tmp_obj.usersSorting["indexByLocation."+Session.get("locationId")] = 1;
var users = [];
var data = Meteor.users.find({
$or:[
{"profile.showInScheduler":{$exists:false}},
{"profile.showInScheduler":true}
],
assignedTo:{$in:[Session.get("locationId")]},
'locations._id':Session.get("locationId"),
"profile.companyId":Session.get("companyId")
},{sort : tmp_obj.usersSorting});
var arr = data.map(function(c) {
var employeeType = c.userSettings.employeeType;
var type = EmployeeType.findOne({_id:employeeType});
var img = Images.findOne({_id: c.picture});
var imgUrl = img ? img.url() : "/images/default-avatar.png";
c.name = c.name || "";
var totalHoursAllLocation = 0;
var totalHoursCurrentLocation = 0;
return {
id: c._id,
title: "t",
width:"2px"
};
});
callback(arr);
},
drop: function(date, jsEvent, ui, resourceId) {
},
eventResize: function( event, dayDelta, minuteDelta, revertFunc, jsEvent, ui, view ) {
},
dayClick: function(date, jsEvent, view,res,res2) {
},
eventClick: function ( event, jsEvent, view ) {
}
}).data().fullCalendar;
/********************* reactive calendar *****************/
this.autorun(function() {
if(Session.get("activeUsers")) {
schedulerSubs = Meteor.subscribe("SchedulesByLocation", Session.get("companyId"), Session.get("locationId"), Session.get("activeUsers"), moment(Session.get("currentDate")).startOf('week').toDate(), moment(Session.get("currentDate")).startOf('week').add(2, "weeks").endOf('isoweek').add(1,"days").toDate());
}
const company = Companies.findOne({_id: Session.get("companyId")});
Session.set("loading", true);
let events = [];
let usersInLocation = Meteor.users.find({
assignedTo: {$in: [Session.get("locationId")]},
'locations._id': Session.get("locationId"),
"profile.companyId": Session.get("companyId")
}).fetch();
let userIds = _.map(usersInLocation, "_id");
userIds.push("temp" + Session.get("companyId") + Session.get("locationId"));
Session.set("activeUsers",userIds);
if(schedulerSubs && schedulerSubs.ready()) {
var data;
SchedulerEvts = Schedules.find({
uid: {$in: userIds},
locationId: Session.get("locationId"),
companyId: Session.get("companyId"),
start: {$gte: moment(Session.get("currentDate")).startOf('week').toDate()},
end: {$lte: moment(Session.get("currentDate")).add(2, "week").endOf('isoweek').toDate()}
}).fetch();
SchedulerEvts.forEach(function (evt) {
var event = null;
var color = "";
var oloc = "";
var attendance = null;
var locationName = "";
var id = evt._id;
event = {
id:id,
type : evt.type,
title: evt.name,
start: evt.start,
end: evt.end,
color:color,
resourceId: evt.uid,
locationName:locationName,
};
events.push(event);
});
if (calendar) {
calendar.removeEvents();
calendar.addEventSource(events);
calendar.refetchResources();
}
}