63 lines
1.5 KiB
JavaScript
63 lines
1.5 KiB
JavaScript
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/** A simple Least Recently Used map */
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class LRUMap {
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constructor( _maxSize) {this._maxSize = _maxSize;
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this._cache = new Map();
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}
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/** Get the current size of the cache */
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get size() {
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return this._cache.size;
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}
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/** Get an entry or undefined if it was not in the cache. Re-inserts to update the recently used order */
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get(key) {
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const value = this._cache.get(key);
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if (value === undefined) {
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return undefined;
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}
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// Remove and re-insert to update the order
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this._cache.delete(key);
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this._cache.set(key, value);
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return value;
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}
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/** Insert an entry and evict an older entry if we've reached maxSize */
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set(key, value) {
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if (this._cache.size >= this._maxSize) {
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// keys() returns an iterator in insertion order so keys().next() gives us the oldest key
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this._cache.delete(this._cache.keys().next().value);
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}
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this._cache.set(key, value);
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}
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/** Remove an entry and return the entry if it was in the cache */
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remove(key) {
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const value = this._cache.get(key);
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if (value) {
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this._cache.delete(key);
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}
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return value;
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}
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/** Clear all entries */
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clear() {
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this._cache.clear();
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}
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/** Get all the keys */
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keys() {
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return Array.from(this._cache.keys());
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}
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/** Get all the values */
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values() {
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const values = [];
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this._cache.forEach(value => values.push(value));
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return values;
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}
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}
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export { LRUMap };
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//# sourceMappingURL=lru.js.map
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