Class Mirror

packages/rrweb-snapshot/src/utils.ts:192–256

}

export class Mirror implements IMirror<Node> {
  private idNodeMap: idNodeMap = new Map();
  private nodeMetaMap: nodeMetaMap = new WeakMap();

  getId(n: Node | undefined | null): number {
    if (!n) return -1;

    const id = this.getMeta(n)?.id;

    // if n is not a serialized Node, use -1 as its id.
    return id ?? -1;
  }

  getNode(id: number): Node | null {
    return this.idNodeMap.get(id) || null;
  }

  getIds(): number[] {
    return Array.from(this.idNodeMap.keys());
  }

  getMeta(n: Node): serializedNodeWithId | null {
    return this.nodeMetaMap.get(n) || null;
  }

  // removes the node from idNodeMap
  // doesn't remove the node from nodeMetaMap
  removeNodeFromMap(n: Node) {
    const id = this.getId(n);
    this.idNodeMap.delete(id);

    if (n.childNodes) {
      n.childNodes.forEach((childNode) =>
        this.removeNodeFromMap(childNode as unknown as Node),
      );
    }
  }
  has(id: number): boolean {
    return this.idNodeMap.has(id);
  }

  hasNode(node: Node): boolean {
    return this.nodeMetaMap.has(node);
  }

  add(n: Node, meta: serializedNodeWithId) {
    const id = meta.id;
    this.idNodeMap.set(id, n);
    this.nodeMetaMap.set(n, meta);
  }

  replace(id: number, n: Node) {
    const oldNode = this.getNode(id);
    if (oldNode) {
      const meta = this.nodeMetaMap.get(oldNode);
      if (meta) this.nodeMetaMap.set(n, meta);
    }
    this.idNodeMap.set(id, n);