implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/eventloop.js

@@ -0,0 +1,128 @@
+/* global requestIdleCallback, requestAnimationFrame, cancelIdleCallback, cancelAnimationFrame */
+
+import * as time from './time.js'
+
+/**
+ * Utility module to work with EcmaScript's event loop.
+ *
+ * @module eventloop
+ */
+
+/**
+ * @type {Array<function>}
+ */
+let queue = []
+
+const _runQueue = () => {
+  for (let i = 0; i < queue.length; i++) {
+    queue[i]()
+  }
+  queue = []
+}
+
+/**
+ * @param {function():void} f
+ */
+export const enqueue = f => {
+  queue.push(f)
+  if (queue.length === 1) {
+    setTimeout(_runQueue, 0)
+  }
+}
+
+/**
+ * @typedef {Object} TimeoutObject
+ * @property {function} TimeoutObject.destroy
+ */
+
+/**
+ * @param {function(number):void} clearFunction
+ */
+const createTimeoutClass = clearFunction => class TT {
+  /**
+   * @param {number} timeoutId
+   */
+  constructor (timeoutId) {
+    this._ = timeoutId
+  }
+
+  destroy () {
+    clearFunction(this._)
+  }
+}
+
+const Timeout = createTimeoutClass(clearTimeout)
+
+/**
+ * @param {number} timeout
+ * @param {function} callback
+ * @return {TimeoutObject}
+ */
+export const timeout = (timeout, callback) => new Timeout(setTimeout(callback, timeout))
+
+const Interval = createTimeoutClass(clearInterval)
+
+/**
+ * @param {number} timeout
+ * @param {function} callback
+ * @return {TimeoutObject}
+ */
+export const interval = (timeout, callback) => new Interval(setInterval(callback, timeout))
+
+/* c8 ignore next */
+export const Animation = createTimeoutClass(arg => typeof requestAnimationFrame !== 'undefined' && cancelAnimationFrame(arg))
+
+/**
+ * @param {function(number):void} cb
+ * @return {TimeoutObject}
+ */
+/* c8 ignore next */
+export const animationFrame = cb => typeof requestAnimationFrame === 'undefined' ? timeout(0, cb) : new Animation(requestAnimationFrame(cb))
+
+/* c8 ignore next */
+// @ts-ignore
+const Idle = createTimeoutClass(arg => typeof cancelIdleCallback !== 'undefined' && cancelIdleCallback(arg))
+
+/**
+ * Note: this is experimental and is probably only useful in browsers.
+ *
+ * @param {function} cb
+ * @return {TimeoutObject}
+ */
+/* c8 ignore next 2 */
+// @ts-ignore
+export const idleCallback = cb => typeof requestIdleCallback !== 'undefined' ? new Idle(requestIdleCallback(cb)) : timeout(1000, cb)
+
+/**
+ * @param {number} timeout Timeout of the debounce action
+ * @param {number} triggerAfter Optional. Trigger callback after a certain amount of time
+ *                              without waiting for debounce.
+ */
+export const createDebouncer = (timeout, triggerAfter = -1) => {
+  let timer = -1
+  /**
+   * @type {number?}
+    */
+  let lastCall = null
+  /**
+   * @param {((...args: any)=>void)?} cb function to trigger after debounce. If null, it will reset the
+   *                         debounce.
+   */
+  return cb => {
+    clearTimeout(timer)
+    if (cb) {
+      if (triggerAfter >= 0) {
+        const now = time.getUnixTime()
+        if (lastCall === null) lastCall = now
+        if (now - lastCall > triggerAfter) {
+          lastCall = null
+          timer = /** @type {any} */ (setTimeout(cb, 0))
+          return
+        }
+      }
+      timer = /** @type {any} */ (setTimeout(() => { lastCall = null; cb() }, timeout))
+    } else {
+      lastCall = null
+    }
+  }
+}