Extract selection strategies to classes (#176)

[poolifier.git] / src / pools / thread / dynamic.ts

import type { PoolOptions } from '../abstract-pool'
import type { ThreadWorkerWithMessageChannel } from './fixed'
import { FixedThreadPool } from './fixed'

/**
 * A thread pool with a dynamic number of threads, but a guaranteed minimum number of threads.
 *
 * This thread pool creates new threads when the others are busy, up to the maximum number of threads.
 * When the maximum number of threads is reached, an event is emitted. If you want to listen to this event, use the pool's `emitter`.
 *
 * @template Data Type of data sent to the worker. This can only be serializable data.
 * @template Response Type of response of execution. This can only be serializable data.
 *
 * @author [Alessandro Pio Ardizio](https://github.com/pioardi)
 * @since 0.0.1
 */
export class DynamicThreadPool<
  Data = unknown,
  Response = unknown
> extends FixedThreadPool<Data, Response> {
  /**
   * Constructs a new poolifier dynamic thread pool.
   *
   * @param min Minimum number of threads which are always active.
   * @param max Maximum number of threads that can be created by this pool.
   * @param filePath Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
   * @param opts Options for this dynamic thread pool. Default: `{ maxTasks: 1000 }`
   */
  public constructor (
    min: number,
    public readonly max: number,
    filePath: string,
    opts: PoolOptions<ThreadWorkerWithMessageChannel> = { maxTasks: 1000 }
  ) {
    super(min, filePath, opts)
  }

  /** @inheritdoc */
  public isDynamic (): boolean {
    return true
  }
}