debounce.js

function debounce(f, delay) {
    var timeout;
    return function() {
        if (f.active) return WARNING('Refresh throttled: operation already started less than 5 seconds ago.');
        f.active = true;
        f.call(this, function() {
            if (delay) {
                if (timeout) clearTimeout(timeout);
                timeout = setTimeout(function() { f.active = false }, delay);
            } else {
                f.active = false;
            }
        });
    };
}