timer JS

A single timeout driven cron task runner, that will execute named of anonymous functions when the time is right.

Either read the Blurb below first of jump down to the syntax / usage

What's it all about?

The idea is simple. Browsers perform better when there is only one timer running on a page, rather than many. It just gives it less to think about, and thus less processing to do.

So all of the cron jobs get set into an object and are run as soon as the milliseconds now is greater than the job's milliseconds value. (Yes all milliseconds are in EPOCH, number of milliseconds since 1-1-1970 - othewise know as UNIX time).

What about things that happen on the same millisecond?

The system has no problem with running tasks that are due on the same millisecond. They are just run in order of when they were added to the cron.

What sort of events can I run?

Repeated events that run every X milliseconds, every X minutes past the hour, or daily
Repeated event that runs every X milliseconds until a time has been met then will no longer run
One off events that run one time only

What sort of functions can I run?

Anonymous functions like this:

function(){//do something in here}

Or named functions like this:

myLoveyFunction()

Things to understand.

1 variable

It is only 1 variable called timer that is used throughout the whole setup. This is so that everything is kept in the same object and uses the same cron runner

Dormant when not in use

The system will not perform any kind of processing until there is actually something in the cron. When there is nothing, it will be dormant. Thus no processing power used.

Structure of the Timer object

timer - interval ( int var that can be set to define how often it loops the cron )
      - cron ( object that holds all the events by millisecond keys )
          [ MILLISECOND VALUE ]
            array 
            { 
              [interval,functionToRun, repeat, until]
              [interval,function(){// anon function;}, repeat , until]
            }
          [ 1429166243679 ]
            array 
            { 
              [1000, functionToRunInOneSecond, false, false]
              [5000, function(){//every 5s till 2020-12-31}, true, 1609455600000]
            }
      - t ( true or false if anything is in the cron or not)

andykillen/timer