зеркало из https://github.com/mozilla/gecko-dev.git
108 строки
2.8 KiB
JavaScript
108 строки
2.8 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/**
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* WeakMapMap is a weakmap collection dual-keyed using an object and a string.
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* This is useful for keeping data compartmentalized e.g. grouped by tab.
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*
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* It's name comes from the internal structure which maps a WeakMap to a map,
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* which contains the target data.
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*
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* Usage:
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* const myWeakMapMap = new WeakMapMap();
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* const key = { randomObject: true };
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* myWeakMapMap.set(key, "text1", "Some value1");
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* myWeakMapMap.set(key, "text2", "Some value2");
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* myWeakMapMap.get(key, "text1"); // Returns "Some value1"
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* myWeakMapMap.get(key, "text2"); // Returns "Some value2"
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* myWeakMapMap.has(key, "text1"); // Returns true
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* myWeakMapMap.has(key, "notakey"); // Returns false
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*/
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"use strict";
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class WeakMapMap {
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constructor() {
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this.clear();
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}
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/**
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* Returns the value associated to the key and nestedKey, or undefined if
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* there is none.
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*
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* @param {Object} key
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* The key associated with the desired value.
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* @param {String} nestedKey
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* The nested key associated with the desired value.
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*/
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get(key, nestedKey) {
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if (!this.has(key, nestedKey)) {
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return undefined;
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}
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return this.store.get(key).get(nestedKey);
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}
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/**
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* Returns the value associated to the key and nestedKey, or undefined if
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* there is none.
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*
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* @param {Object} key
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* The key associated with the desired value.
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* @param {String} nestedKey
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* The nested key associated with the desired value.
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*/
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has(key, nestedKey) {
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const hasKey = this.store.has(key);
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return hasKey && this.store.get(key).has(nestedKey);
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}
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/**
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*
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* @param {Object} key
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* The key associated with the value.
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* @param {String} nestedKey
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* The nested key associated with the value.
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* @param {any} value
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* The value to add.
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*/
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set(key, nestedKey, value) {
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if (!this.store.has(key)) {
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this.store.set(key, new Map());
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}
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const innerMap = this.store.get(key);
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innerMap.set(nestedKey, value);
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}
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/**
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* Removes the value associated to the key and nestedKey.
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*
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* @param {Object} key
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* The key associated with the desired value.
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* @param {String} nestedKey
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* The nested key associated with the desired value.
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*
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* @returns True if an element in the store has been removed successfully.
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* False if the key is not found in the store.
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*/
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delete(key, nestedKey) {
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if (!this.store.has(key)) {
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return false;
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}
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return this.store.get(key).delete(nestedKey);
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}
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/**
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* Clear the store.
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*/
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clear() {
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this.store = new WeakMap();
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}
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}
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module.exports = WeakMapMap;
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