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Diffstat (limited to 'ext/mixed/js/cache-map.js')
-rw-r--r-- | ext/mixed/js/cache-map.js | 140 |
1 files changed, 0 insertions, 140 deletions
diff --git a/ext/mixed/js/cache-map.js b/ext/mixed/js/cache-map.js deleted file mode 100644 index c7d72e6b..00000000 --- a/ext/mixed/js/cache-map.js +++ /dev/null @@ -1,140 +0,0 @@ -/* - * Copyright (C) 2020-2021 Yomichan Authors - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <https://www.gnu.org/licenses/>. - */ - -/** - * Class which caches a map of values, keeping the most recently accessed values. - */ -class CacheMap { - /** - * Creates a new CacheMap. - * @param maxSize The maximum number of entries able to be stored in the cache. - */ - constructor(maxSize) { - if (!( - typeof maxSize === 'number' && - Number.isFinite(maxSize) && - maxSize >= 0 && - Math.floor(maxSize) === maxSize - )) { - throw new Error('Invalid maxCount'); - } - - this._maxSize = maxSize; - this._map = new Map(); - this._listFirst = this._createNode(null, null); - this._listLast = this._createNode(null, null); - this._resetEndNodes(); - } - - /** - * Returns the number of items in the cache. - */ - get size() { - return this._map.size; - } - - /** - * Returns the maximum number of items that can be added to the cache. - */ - get maxSize() { - return this._maxSize; - } - - /** - * Returns whether or not an element exists at the given key. - * @param key The key of the element. - * @returns `true` if an element with the specified key exists, `false` otherwise. - */ - has(key) { - return this._map.has(key); - } - - /** - * Gets an element at the given key, if it exists. Otherwise, returns undefined. - * @param key The key of the element. - * @returns The existing value at the key, if any; `undefined` otherwise. - */ - get(key) { - const node = this._map.get(key); - if (typeof node === 'undefined') { return void 0; } - this._updateRecency(node); - return node.value; - } - - /** - * Sets a value at a given key. - * @param key The key of the element. - * @param value The value to store in the cache. - */ - set(key, value) { - let node = this._map.get(key); - if (typeof node !== 'undefined') { - this._updateRecency(node); - node.value = value; - } else { - if (this._maxSize <= 0) { return; } - - node = this._createNode(key, value); - this._addNode(node, this._listFirst); - this._map.set(key, node); - - // Remove - for (let removeCount = this._map.size - this._maxSize; removeCount > 0; --removeCount) { - node = this._listLast.previous; - this._removeNode(node); - this._map.delete(node.key); - } - } - } - - /** - * Clears the cache. - */ - clear() { - this._map.clear(); - this._resetEndNodes(); - } - - // Private - - _updateRecency(node) { - this._removeNode(node); - this._addNode(node, this._listFirst); - } - - _createNode(key, value) { - return {key, value, previous: null, next: null}; - } - - _addNode(node, previous) { - const next = previous.next; - node.next = next; - node.previous = previous; - previous.next = node; - next.previous = node; - } - - _removeNode(node) { - node.next.previous = node.previous; - node.previous.next = node.next; - } - - _resetEndNodes() { - this._listFirst.next = this._listLast; - this._listLast.previous = this._listFirst; - } -} |