51 lines
1.2 KiB
TypeScript
51 lines
1.2 KiB
TypeScript
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type LimitedMapRecord<V> = Record<string, { value: V; la: number }>;
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export class LimitedMap<V> {
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constructor(private maxSize: number, private map: LimitedMapRecord<V> = {}) {
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}
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set(key: string, value: V) {
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if (Object.keys(this.map).length >= this.maxSize) {
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// Remove the oldest key before adding a new one
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const oldestKey = this.getOldestKey();
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delete this.map[oldestKey!];
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}
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this.map[key] = { value, la: Date.now() };
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}
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get(key: string): V | undefined {
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const entry = this.map[key];
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if (entry) {
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// Update the last accessed timestamp
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entry.la = Date.now();
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return entry.value;
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}
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return undefined;
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}
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remove(key: string) {
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delete this.map[key];
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}
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toJSON() {
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return this.map;
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}
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private getOldestKey(): string | undefined {
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let oldestKey: string | undefined;
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let oldestTimestamp: number | undefined;
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for (const key in this.map) {
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if (Object.prototype.hasOwnProperty.call(this.map, key)) {
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const entry = this.map[key];
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if (!oldestTimestamp || entry.la < oldestTimestamp) {
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oldestKey = key;
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oldestTimestamp = entry.la;
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}
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}
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}
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return oldestKey;
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}
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}
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