Add eslint-plugin-jsdoc (#142)

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

diff --git a/src/pools/thread/dynamic.ts b/src/pools/thread/dynamic.ts
index e80276d976640c25a9fe194847289e1ba0d7db45..c8e93850e537e0e1499b3c4ae72caa918704b6d5 100644 (file)
--- a/src/pools/thread/dynamic.ts
+++ b/src/pools/thread/dynamic.ts
@@ -1,47 +1,52 @@
-import { EventEmitter } from 'events'
-import type { FixedThreadPoolOptions, WorkerWithMessageChannel } from './fixed'
+import type { JSONValue, MessageValue } from '../../utility-types'
+import type { PoolOptions } from '../abstract-pool'
+import type { ThreadWorkerWithMessageChannel } from './fixed'
 import { FixedThreadPool } from './fixed'
 
-class MyEmitter extends EventEmitter {}
-
-export type DynamicThreadPoolOptions = FixedThreadPoolOptions
-
 /**
- * A thread pool with a min/max number of threads, is possible to execute tasks in sync or async mode as you prefer.
+ * A thread pool with a dynamic number of threads, but a guaranteed minimum number of threads.
  *
- * This thread pool will create new workers when the other ones are busy, until the max number of threads,
- * when the max number of threads is reached, an event will be emitted, if you want to listen this event use the emitter method.
+ * 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.
+ * @template Response Type of response of execution.
  *
  * @author [Alessandro Pio Ardizio](https://github.com/pioardi)
  * @since 0.0.1
  */
 export class DynamicThreadPool<
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  Data = any,
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  Response = any
+  Data extends JSONValue = JSONValue,
+  Response extends JSONValue = JSONValue
 > extends FixedThreadPool<Data, Response> {
-  public readonly emitter: MyEmitter
-
   /**
-   * @param min Min number of threads that will be always active
-   * @param max Max number of threads that will be active
-   * @param filename A file path with implementation of `ThreadWorker` class, relative path is fine.
-   * @param opts An object with possible options for example `errorHandler`, `onlineHandler`. Default: `{ maxTasks: 1000 }`
+   * 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 filename Path to an implementation of a `ThreadWorker` file, which can be relative or absolute.
+   * @param opts Options for this fixed thread pool. Default: `{ maxTasks: 1000 }`
    */
   public constructor (
-    public readonly min: number,
+    min: number,
     public readonly max: number,
-    public readonly filename: string,
-    public readonly opts: DynamicThreadPoolOptions = { maxTasks: 1000 }
+    filename: string,
+    opts: PoolOptions<ThreadWorkerWithMessageChannel> = { maxTasks: 1000 }
   ) {
     super(min, filename, opts)
-
-    this.emitter = new MyEmitter()
   }
 
-  protected chooseWorker (): WorkerWithMessageChannel {
-    let worker: WorkerWithMessageChannel | undefined
+  /**
+   * Choose a thread for the next task.
+   *
+   * It will first check for and return an idle thread.
+   * If all threads are busy, then it will try to create a new one up to the `max` thread count.
+   * If the max thread count is reached, the emitter will emit a `FullPool` event and it will fall back to using a round robin algorithm to distribute the load.
+   *
+   * @returns Thread worker.
+   */
+  protected chooseWorker (): ThreadWorkerWithMessageChannel {
+    let worker: ThreadWorkerWithMessageChannel | undefined
     for (const entry of this.tasks) {
       if (entry[1] === 0) {
         worker = entry[0]
@@ -58,15 +63,12 @@ export class DynamicThreadPool<
         return super.chooseWorker()
       }
       // all workers are busy create a new worker
-      const worker = this.newWorker()
-      worker.port2?.on('message', (message: { kill?: number }) => {
+      const worker = this.internalNewWorker()
+      worker.port2?.on('message', (message: MessageValue<Data>) => {
         if (message.kill) {
-          worker.postMessage({ kill: 1 })
-          void worker.terminate()
-          // clean workers from data structures
-          const workerIndex = this.workers.indexOf(worker)
-          this.workers.splice(workerIndex, 1)
-          this.tasks.delete(worker)
+          this.sendToWorker(worker, { kill: 1 })
+          void this.destroyWorker(worker)
+          this.removeWorker(worker)
         }
       })
       return worker