sharp-vibrant/src/quantizer/pqueue.ts

Extract prominent colors from an image in a node environment using sharp.

export interface PQueueComparator<T> {
  (a: T, b: T): number
}

export default class PQueue<T> {
  contents: T[];

  #sorted: boolean;

  #comparator: PQueueComparator<T>;

  private sort(): void {
    if (!this.#sorted) {
      this.contents.sort(this.#comparator);
      this.#sorted = true;
    }
  }

  constructor(comparator: PQueueComparator<T>) {
    this.#comparator = comparator;
    this.contents = [];
    this.#sorted = false;
  }

  push(item: T): void {
    this.contents.push(item);
    this.#sorted = false;
  }

  peek(index?: number): T {
    this.sort();
    return this.contents[typeof index === 'number' ? index : this.contents.length - 1];
  }

  pop(): T {
    this.sort();
    return this.contents.pop()!;
  }

  get size(): number {
    return this.contents.length;
  }

  map<U>(mapper: (item: T, index: number) => any): U[] {
    this.sort();
    return this.contents.map(mapper);
  }
}