61 lines
1.9 KiB
JavaScript
61 lines
1.9 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.Computed = void 0;
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exports.computed = computed;
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const system_js_1 = require("./system.js");
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function computed(getter) {
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return new Computed(getter);
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}
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class Computed {
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constructor(getter) {
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this.getter = getter;
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this.cachedValue = undefined;
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// Dependency
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this.subs = undefined;
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this.subsTail = undefined;
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// Subscriber
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this.deps = undefined;
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this.depsTail = undefined;
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this.trackId = 0;
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this.dirtyLevel = 3 /* DirtyLevels.Dirty */;
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this.canPropagate = false;
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}
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get() {
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let dirtyLevel = this.dirtyLevel;
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if (dirtyLevel === 2 /* DirtyLevels.MaybeDirty */) {
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system_js_1.Subscriber.resolveMaybeDirty(this);
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dirtyLevel = this.dirtyLevel;
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}
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if (dirtyLevel >= 3 /* DirtyLevels.Dirty */) {
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this.update();
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}
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const activeTrackId = system_js_1.System.activeTrackId;
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if (activeTrackId !== 0) {
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const subsTail = this.subsTail;
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if (subsTail === undefined || subsTail.trackId !== activeTrackId) {
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system_js_1.Dependency.link(this, system_js_1.System.activeSub);
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}
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}
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return this.cachedValue;
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}
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update() {
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const prevSub = system_js_1.Subscriber.startTrack(this);
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const oldValue = this.cachedValue;
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let newValue;
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try {
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newValue = this.getter(oldValue);
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}
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finally {
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system_js_1.Subscriber.endTrack(this, prevSub);
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}
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if (oldValue !== newValue) {
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this.cachedValue = newValue;
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const subs = this.subs;
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if (subs !== undefined) {
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system_js_1.Dependency.propagate(subs);
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}
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}
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}
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}
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exports.Computed = Computed;
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