feat: introduce worker node queue back pressure detection

[poolifier.git] / src / pools / worker-node.ts

diff --git a/src/pools/worker-node.ts b/src/pools/worker-node.ts
index 923fe9b222a4ea9dc4279294d51d0755f67f1ba7..64880fcb9820c098e37fb103bd27b8563073833a 100644 (file)
--- a/src/pools/worker-node.ts
+++ b/src/pools/worker-node.ts
@@ -20,25 +20,35 @@ import {
  */
 export class WorkerNode<Worker extends IWorker, Data = unknown>
 implements IWorkerNode<Worker, Data> {
+  /** @inheritdoc */
   public readonly worker: Worker
+  /** @inheritdoc */
   public readonly info: WorkerInfo
+  /** @inheritdoc */
+  public messageChannel?: MessageChannel
+  /** @inheritdoc */
   public usage: WorkerUsage
-  public taskFunctions!: string[]
   private readonly tasksUsage: Map<string, WorkerUsage>
   private readonly tasksQueue: Queue<Task<Data>>
+  private readonly tasksQueueBackPressureMaxSize: number
 
   /**
    * Constructs a new worker node.
    *
    * @param worker - The worker.
    * @param workerType - The worker type.
+   * @param poolMaxSize - The pool maximum size.
    */
-  constructor (worker: Worker, workerType: WorkerType) {
+  constructor (worker: Worker, workerType: WorkerType, poolMaxSize: number) {
     this.worker = worker
     this.info = this.initWorkerInfo(worker, workerType)
+    if (workerType === WorkerTypes.thread) {
+      this.messageChannel = new MessageChannel()
+    }
     this.usage = this.initWorkerUsage()
     this.tasksUsage = new Map<string, WorkerUsage>()
     this.tasksQueue = new Queue<Task<Data>>()
+    this.tasksQueueBackPressureMaxSize = Math.pow(poolMaxSize, 2)
   }
 
   /** @inheritdoc */
@@ -70,6 +80,11 @@ implements IWorkerNode<Worker, Data> {
     this.tasksQueue.clear()
   }
 
+  /** @inheritdoc */
+  public hasBackPressure (): boolean {
+    return this.tasksQueueSize() >= this.tasksQueueBackPressureMaxSize
+  }
+
   /** @inheritdoc */
   public resetUsage (): void {
     this.usage = this.initWorkerUsage()
@@ -78,23 +93,28 @@ implements IWorkerNode<Worker, Data> {
 
   /** @inheritdoc */
   public closeChannel (): void {
-    if (this.info.messageChannel != null) {
-      this.info.messageChannel?.port1.unref()
-      this.info.messageChannel?.port2.unref()
-      this.info.messageChannel?.port1.close()
-      this.info.messageChannel?.port2.close()
-      delete this.info.messageChannel
+    if (this.messageChannel != null) {
+      this.messageChannel?.port1.unref()
+      this.messageChannel?.port2.unref()
+      this.messageChannel?.port1.close()
+      this.messageChannel?.port2.close()
+      delete this.messageChannel
     }
   }
 
   /** @inheritdoc */
   public getTaskWorkerUsage (name: string): WorkerUsage | undefined {
+    if (!Array.isArray(this.info.taskFunctions)) {
+      throw new Error(
+        `Cannot get task worker usage for task function name '${name}' when task function names list is not yet defined`
+      )
+    }
     if (
       name === DEFAULT_TASK_NAME &&
-      Array.isArray(this.taskFunctions) &&
-      this.taskFunctions.length > 1
+      Array.isArray(this.info.taskFunctions) &&
+      this.info.taskFunctions.length > 1
     ) {
-      name = this.taskFunctions[1]
+      name = this.info.taskFunctions[1]
     }
     if (!this.tasksUsage.has(name)) {
       this.tasksUsage.set(name, this.initTaskWorkerUsage(name))
@@ -107,10 +127,7 @@ implements IWorkerNode<Worker, Data> {
       id: this.getWorkerId(worker, workerType),
       type: workerType,
       dynamic: false,
-      ready: false,
-      ...(workerType === WorkerTypes.thread && {
-        messageChannel: new MessageChannel()
-      })
+      ready: false
     }
   }