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authorRyan Dahl <ry@tinyclouds.org>2019-10-04 20:28:51 -0400
committerGitHub <noreply@github.com>2019-10-04 20:28:51 -0400
commitb81e5db17aa8b3088d6034ddf86b79c69410f012 (patch)
tree579e4c23d60d1b0d038156bc28a04f74ea87b2f0 /js/timers.ts
parent9049213867d30f7df090a83b6baf3e0717a4d2d2 (diff)
Merge deno_cli_snapshots into deno_cli (#3064)
Diffstat (limited to 'js/timers.ts')
-rw-r--r--js/timers.ts280
1 files changed, 0 insertions, 280 deletions
diff --git a/js/timers.ts b/js/timers.ts
deleted file mode 100644
index 5bc4922e3..000000000
--- a/js/timers.ts
+++ /dev/null
@@ -1,280 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-import { assert } from "./util.ts";
-import { window } from "./window.ts";
-import * as dispatch from "./dispatch.ts";
-import { sendSync, sendAsync } from "./dispatch_json.ts";
-
-const { console } = window;
-
-interface Timer {
- id: number;
- callback: () => void;
- delay: number;
- due: number;
- repeat: boolean;
- scheduled: boolean;
-}
-
-// We'll subtract EPOCH every time we retrieve the time with Date.now(). This
-// ensures that absolute time values stay below UINT32_MAX - 2, which is the
-// maximum object key that EcmaScript considers "numerical". After running for
-// about a month, this is no longer true, and Deno explodes.
-// TODO(piscisaureus): fix that ^.
-const EPOCH = Date.now();
-const APOCALYPSE = 2 ** 32 - 2;
-
-// Timeout values > TIMEOUT_MAX are set to 1.
-const TIMEOUT_MAX = 2 ** 31 - 1;
-
-let globalTimeoutDue: number | null = null;
-
-let nextTimerId = 1;
-const idMap = new Map<number, Timer>();
-const dueMap: { [due: number]: Timer[] } = Object.create(null);
-
-function getTime(): number {
- // TODO: use a monotonic clock.
- const now = Date.now() - EPOCH;
- assert(now >= 0 && now < APOCALYPSE);
- return now;
-}
-
-function clearGlobalTimeout(): void {
- globalTimeoutDue = null;
- sendSync(dispatch.OP_GLOBAL_TIMER_STOP);
-}
-
-async function setGlobalTimeout(due: number, now: number): Promise<void> {
- // Since JS and Rust don't use the same clock, pass the time to rust as a
- // relative time value. On the Rust side we'll turn that into an absolute
- // value again.
- const timeout = due - now;
- assert(timeout >= 0);
-
- // Send message to the backend.
- globalTimeoutDue = due;
- await sendAsync(dispatch.OP_GLOBAL_TIMER, { timeout });
- // eslint-disable-next-line @typescript-eslint/no-use-before-define
- fireTimers();
-}
-
-function setOrClearGlobalTimeout(due: number | null, now: number): void {
- if (due == null) {
- clearGlobalTimeout();
- } else {
- setGlobalTimeout(due, now);
- }
-}
-
-function schedule(timer: Timer, now: number): void {
- assert(!timer.scheduled);
- assert(now <= timer.due);
- // Find or create the list of timers that will fire at point-in-time `due`.
- let list = dueMap[timer.due];
- if (list === undefined) {
- list = dueMap[timer.due] = [];
- }
- // Append the newly scheduled timer to the list and mark it as scheduled.
- list.push(timer);
- timer.scheduled = true;
- // If the new timer is scheduled to fire before any timer that existed before,
- // update the global timeout to reflect this.
- if (globalTimeoutDue === null || globalTimeoutDue > timer.due) {
- setOrClearGlobalTimeout(timer.due, now);
- }
-}
-
-function unschedule(timer: Timer): void {
- if (!timer.scheduled) {
- return;
- }
- // Find the list of timers that will fire at point-in-time `due`.
- const list = dueMap[timer.due];
- if (list.length === 1) {
- // Time timer is the only one in the list. Remove the entire list.
- assert(list[0] === timer);
- delete dueMap[timer.due];
- // If the unscheduled timer was 'next up', find when the next timer that
- // still exists is due, and update the global alarm accordingly.
- if (timer.due === globalTimeoutDue) {
- let nextTimerDue: number | null = null;
- for (const key in dueMap) {
- nextTimerDue = Number(key);
- break;
- }
- setOrClearGlobalTimeout(nextTimerDue, getTime());
- }
- } else {
- // Multiple timers that are due at the same point in time.
- // Remove this timer from the list.
- const index = list.indexOf(timer);
- assert(index > -1);
- list.splice(index, 1);
- }
-}
-
-function fire(timer: Timer): void {
- // If the timer isn't found in the ID map, that means it has been cancelled
- // between the timer firing and the promise callback (this function).
- if (!idMap.has(timer.id)) {
- return;
- }
- // Reschedule the timer if it is a repeating one, otherwise drop it.
- if (!timer.repeat) {
- // One-shot timer: remove the timer from this id-to-timer map.
- idMap.delete(timer.id);
- } else {
- // Interval timer: compute when timer was supposed to fire next.
- // However make sure to never schedule the next interval in the past.
- const now = getTime();
- timer.due = Math.max(now, timer.due + timer.delay);
- schedule(timer, now);
- }
- // Call the user callback. Intermediate assignment is to avoid leaking `this`
- // to it, while also keeping the stack trace neat when it shows up in there.
- const callback = timer.callback;
- callback();
-}
-
-function fireTimers(): void {
- const now = getTime();
- // Bail out if we're not expecting the global timer to fire.
- if (globalTimeoutDue === null) {
- return;
- }
- // After firing the timers that are due now, this will hold the due time of
- // the first timer that hasn't fired yet.
- let nextTimerDue: number | null = null;
- // Walk over the keys of the 'due' map. Since dueMap is actually a regular
- // object and its keys are numerical and smaller than UINT32_MAX - 2,
- // keys are iterated in ascending order.
- for (const key in dueMap) {
- // Convert the object key (a string) to a number.
- const due = Number(key);
- // Break out of the loop if the next timer isn't due to fire yet.
- if (Number(due) > now) {
- nextTimerDue = due;
- break;
- }
- // Get the list of timers that have this due time, then drop it.
- const list = dueMap[key];
- delete dueMap[key];
- // Fire all the timers in the list.
- for (const timer of list) {
- // With the list dropped, the timer is no longer scheduled.
- timer.scheduled = false;
- // Place the callback on the microtask queue.
- Promise.resolve(timer).then(fire);
- }
- }
-
- // Update the global alarm to go off when the first-up timer that hasn't fired
- // yet is due.
- setOrClearGlobalTimeout(nextTimerDue, now);
-}
-
-export type Args = unknown[];
-
-function checkThis(thisArg: unknown): void {
- if (thisArg !== null && thisArg !== undefined && thisArg !== window) {
- throw new TypeError("Illegal invocation");
- }
-}
-
-function checkBigInt(n: unknown): void {
- if (typeof n === "bigint") {
- throw new TypeError("Cannot convert a BigInt value to a number");
- }
-}
-
-function setTimer(
- cb: (...args: Args) => void,
- delay: number,
- args: Args,
- repeat: boolean
-): number {
- // Bind `args` to the callback and bind `this` to window(global).
- const callback: () => void = cb.bind(window, ...args);
- // In the browser, the delay value must be coercible to an integer between 0
- // and INT32_MAX. Any other value will cause the timer to fire immediately.
- // We emulate this behavior.
- const now = getTime();
- if (delay > TIMEOUT_MAX) {
- console.warn(
- `${delay} does not fit into` +
- " a 32-bit signed integer." +
- "\nTimeout duration was set to 1."
- );
- delay = 1;
- }
- delay = Math.max(0, delay | 0);
-
- // Create a new, unscheduled timer object.
- const timer = {
- id: nextTimerId++,
- callback,
- args,
- delay,
- due: now + delay,
- repeat,
- scheduled: false
- };
- // Register the timer's existence in the id-to-timer map.
- idMap.set(timer.id, timer);
- // Schedule the timer in the due table.
- schedule(timer, now);
- return timer.id;
-}
-
-/** Sets a timer which executes a function once after the timer expires. */
-export function setTimeout(
- cb: (...args: Args) => void,
- delay = 0,
- ...args: Args
-): number {
- checkBigInt(delay);
- // @ts-ignore
- checkThis(this);
- return setTimer(cb, delay, args, false);
-}
-
-/** Repeatedly calls a function , with a fixed time delay between each call. */
-export function setInterval(
- cb: (...args: Args) => void,
- delay = 0,
- ...args: Args
-): number {
- checkBigInt(delay);
- // @ts-ignore
- checkThis(this);
- return setTimer(cb, delay, args, true);
-}
-
-/** Clears a previously set timer by id. AKA clearTimeout and clearInterval. */
-function clearTimer(id: number): void {
- id = Number(id);
- const timer = idMap.get(id);
- if (timer === undefined) {
- // Timer doesn't exist any more or never existed. This is not an error.
- return;
- }
- // Unschedule the timer if it is currently scheduled, and forget about it.
- unschedule(timer);
- idMap.delete(timer.id);
-}
-
-export function clearTimeout(id = 0): void {
- checkBigInt(id);
- if (id === 0) {
- return;
- }
- clearTimer(id);
-}
-
-export function clearInterval(id = 0): void {
- checkBigInt(id);
- if (id === 0) {
- return;
- }
- clearTimer(id);
-}