@thi.ng/ecs/caches/lru.js

Entity Component System based around typed arrays & sparse sets

import { DCons } from "@thi.ng/dcons/dcons";
class LRU {
  items;
  index;
  capacity;
  constructor(cap) {
    this.items = new DCons();
    this.index = /* @__PURE__ */ new Map();
    this.capacity = cap;
  }
  keys() {
    return this.index.keys();
  }
  clear() {
    this.items.release();
    this.index.clear();
  }
  release() {
    this.clear();
    return true;
  }
  set(key, val) {
    const { items, index } = this;
    let node = index.get(key);
    if (node) {
      node.value.v = val;
      items.asHead(node);
    } else {
      items.prepend({ k: key, v: val });
      index.set(key, items.head);
      while (items.length > this.capacity) {
        this.index.delete(this.items.pop().k);
      }
    }
    return val;
  }
  get(key) {
    const node = this.index.get(key);
    if (node) {
      this.items.asHead(node);
      return node.value.v;
    }
  }
  getSet(key, notFound) {
    let val = this.get(key);
    return val !== void 0 ? val : this.set(key, notFound());
  }
  delete(key) {
    const node = this.index.get(key);
    if (node) {
      this.index.delete(key);
      this.items.remove(node);
      return true;
    }
    return false;
  }
}
export {
  LRU
};