Improvements for #161 (#169)

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

diff --git a/src/pools/cluster/dynamic.ts b/src/pools/cluster/dynamic.ts
index f2375a02d6e1babf875d27b40f01782849828af0..e97ab4a9be2fdbe536fd8ac5e6fa8ae65ea1b41d 100644 (file)
--- a/src/pools/cluster/dynamic.ts
+++ b/src/pools/cluster/dynamic.ts
@@ -1,28 +1,32 @@
 import type { Worker } from 'cluster'
-import type { MessageValue } from '../../utility-types'
+import type { JSONValue } from '../../utility-types'
+import { isKillBehavior, KillBehaviors } from '../../worker/worker-options'
 import type { ClusterPoolOptions } from './fixed'
 import { FixedClusterPool } from './fixed'
 
 /**
- * A cluster pool with a min/max number of workers, is possible to execute tasks in sync or async mode as you prefer.
+ * A cluster pool with a dynamic number of workers, but a guaranteed minimum number of workers.
  *
- * This cluster pool will create new workers when the other ones are busy, until the max number of workers,
- * when the max number of workers is reached, an event will be emitted, if you want to listen this event use the emitter method.
+ * This cluster pool creates new workers when the others are busy, up to the maximum number of workers.
+ * When the maximum number of workers 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 [Christopher Quadflieg](https://github.com/Shinigami92)
  * @since 2.0.0
  */
 export class DynamicClusterPool<
-  // 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 FixedClusterPool<Data, Response> {
   /**
-   * @param min Min number of workers that will be always active
-   * @param max Max number of workers that will be active
-   * @param filename A file path with implementation of `ClusterWorker` class, relative path is fine.
-   * @param opts An object with possible options for example `errorHandler`, `onlineHandler`. Default: `{ maxTasks: 1000 }`
+   * Constructs a new poolifier dynamic cluster pool.
+   *
+   * @param min Minimum number of workers which are always active.
+   * @param max Maximum number of workers that can be created by this pool.
+   * @param filename Path to an implementation of a `ClusterWorker` file, which can be relative or absolute.
+   * @param opts Options for this fixed cluster pool. Default: `{ maxTasks: 1000 }`
    */
   public constructor (
     min: number,
@@ -33,36 +37,41 @@ export class DynamicClusterPool<
     super(min, filename, opts)
   }
 
+  /**
+   * Choose a worker for the next task.
+   *
+   * It will first check for and return an idle worker.
+   * If all workers are busy, then it will try to create a new one up to the `max` worker count.
+   * If the max worker 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 Cluster worker.
+   */
   protected chooseWorker (): Worker {
-    let worker: Worker | undefined
-    for (const entry of this.tasks) {
-      if (entry[1] === 0) {
-        worker = entry[0]
-        break
+    for (const [worker, numberOfTasks] of this.tasks) {
+      if (numberOfTasks === 0) {
+        // A worker is free, use it
+        return worker
       }
     }
 
-    if (worker) {
-      // a worker is free, use it
-      return worker
-    } else {
-      if (this.workers.length === this.max) {
-        this.emitter.emit('FullPool')
-        return super.chooseWorker()
-      }
-      // all workers are busy create a new worker
-      const worker = this.internalNewWorker()
-      worker.on('message', (message: MessageValue<Data>) => {
-        if (message.kill) {
-          this.sendToWorker(worker, { kill: 1 })
-          void this.destroyWorker(worker)
-          // clean workers from data structures
-          const workerIndex = this.workers.indexOf(worker)
-          this.workers.splice(workerIndex, 1)
-          this.tasks.delete(worker)
-        }
-      })
-      return worker
+    if (this.workers.length === this.max) {
+      this.emitter.emit('FullPool')
+      return super.chooseWorker()
     }
+
+    // All workers are busy, create a new worker
+    const workerCreated = this.createAndSetupWorker()
+    this.registerWorkerMessageListener<Data>(workerCreated, message => {
+      const tasksInProgress = this.tasks.get(workerCreated)
+      if (
+        isKillBehavior(KillBehaviors.HARD, message.kill) ||
+        tasksInProgress === 0
+      ) {
+        // Kill received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime)
+        this.sendToWorker(workerCreated, { kill: 1 })
+        void this.destroyWorker(workerCreated)
+      }
+    })
+    return workerCreated
   }
 }