111 lines
2.8 KiB
JavaScript
111 lines
2.8 KiB
JavaScript
var frame = 0, // is an animation frame pending?
|
||
timeout = 0, // is a timeout pending?
|
||
interval = 0, // are any timers active?
|
||
pokeDelay = 1000, // how frequently we check for clock skew
|
||
taskHead,
|
||
taskTail,
|
||
clockLast = 0,
|
||
clockNow = 0,
|
||
clockSkew = 0,
|
||
clock = typeof performance === "object" && performance.now ? performance : Date,
|
||
setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : function(f) { setTimeout(f, 17); };
|
||
|
||
export function now() {
|
||
return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
|
||
}
|
||
|
||
function clearNow() {
|
||
clockNow = 0;
|
||
}
|
||
|
||
export function Timer() {
|
||
this._call =
|
||
this._time =
|
||
this._next = null;
|
||
}
|
||
|
||
Timer.prototype = timer.prototype = {
|
||
constructor: Timer,
|
||
restart: function(callback, delay, time) {
|
||
if (typeof callback !== "function") throw new TypeError("callback is not a function");
|
||
time = (time == null ? now() : +time) + (delay == null ? 0 : +delay);
|
||
if (!this._next && taskTail !== this) {
|
||
if (taskTail) taskTail._next = this;
|
||
else taskHead = this;
|
||
taskTail = this;
|
||
}
|
||
this._call = callback;
|
||
this._time = time;
|
||
sleep();
|
||
},
|
||
stop: function() {
|
||
if (this._call) {
|
||
this._call = null;
|
||
this._time = Infinity;
|
||
sleep();
|
||
}
|
||
}
|
||
};
|
||
|
||
export function timer(callback, delay, time) {
|
||
var t = new Timer;
|
||
t.restart(callback, delay, time);
|
||
return t;
|
||
}
|
||
|
||
export function timerFlush() {
|
||
now(); // Get the current time, if not already set.
|
||
++frame; // Pretend we’ve set an alarm, if we haven’t already.
|
||
var t = taskHead, e;
|
||
while (t) {
|
||
if ((e = clockNow - t._time) >= 0) t._call.call(undefined, e);
|
||
t = t._next;
|
||
}
|
||
--frame;
|
||
}
|
||
|
||
function wake() {
|
||
clockNow = (clockLast = clock.now()) + clockSkew;
|
||
frame = timeout = 0;
|
||
try {
|
||
timerFlush();
|
||
} finally {
|
||
frame = 0;
|
||
nap();
|
||
clockNow = 0;
|
||
}
|
||
}
|
||
|
||
function poke() {
|
||
var now = clock.now(), delay = now - clockLast;
|
||
if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
|
||
}
|
||
|
||
function nap() {
|
||
var t0, t1 = taskHead, t2, time = Infinity;
|
||
while (t1) {
|
||
if (t1._call) {
|
||
if (time > t1._time) time = t1._time;
|
||
t0 = t1, t1 = t1._next;
|
||
} else {
|
||
t2 = t1._next, t1._next = null;
|
||
t1 = t0 ? t0._next = t2 : taskHead = t2;
|
||
}
|
||
}
|
||
taskTail = t0;
|
||
sleep(time);
|
||
}
|
||
|
||
function sleep(time) {
|
||
if (frame) return; // Soonest alarm already set, or will be.
|
||
if (timeout) timeout = clearTimeout(timeout);
|
||
var delay = time - clockNow; // Strictly less than if we recomputed clockNow.
|
||
if (delay > 24) {
|
||
if (time < Infinity) timeout = setTimeout(wake, time - clock.now() - clockSkew);
|
||
if (interval) interval = clearInterval(interval);
|
||
} else {
|
||
if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
|
||
frame = 1, setFrame(wake);
|
||
}
|
||
}
|