41 lines
1.2 KiB
JavaScript
41 lines
1.2 KiB
JavaScript
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import { addUniqueItem, removeItem } from './array.mjs';
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class SubscriptionManager {
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constructor() {
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this.subscriptions = [];
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}
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add(handler) {
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addUniqueItem(this.subscriptions, handler);
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return () => removeItem(this.subscriptions, handler);
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}
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notify(a, b, c) {
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const numSubscriptions = this.subscriptions.length;
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if (!numSubscriptions)
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return;
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if (numSubscriptions === 1) {
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/**
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* If there's only a single handler we can just call it without invoking a loop.
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*/
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this.subscriptions[0](a, b, c);
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}
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else {
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for (let i = 0; i < numSubscriptions; i++) {
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/**
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* Check whether the handler exists before firing as it's possible
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* the subscriptions were modified during this loop running.
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*/
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const handler = this.subscriptions[i];
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handler && handler(a, b, c);
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}
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}
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}
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getSize() {
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return this.subscriptions.length;
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}
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clear() {
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this.subscriptions.length = 0;
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}
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}
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export { SubscriptionManager };
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