refactor: cleanup message passing code
[poolifier.git] / src / pools / abstract-pool.ts
index 56dd7fa9296265078f863d342338da0457309919..18d4fb8362dcfdd9de125e0e83ca51aa91b98ff3 100644 (file)
@@ -1,6 +1,7 @@
 import { randomUUID } from 'node:crypto'
 import { performance } from 'node:perf_hooks'
 import { existsSync } from 'node:fs'
+import { type TransferListItem } from 'node:worker_threads'
 import type {
   MessageValue,
   PromiseResponseWrapper,
@@ -10,7 +11,6 @@ import {
   DEFAULT_TASK_NAME,
   DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
   EMPTY_FUNCTION,
-  isAsyncFunction,
   isKillBehavior,
   isPlainObject,
   median,
@@ -92,6 +92,10 @@ export abstract class AbstractPool<
    * The start timestamp of the pool.
    */
   private readonly startTimestamp
+  /**
+   * The task function names.
+   */
+  private taskFunctions!: string[]
 
   /**
    * Constructs a new poolifier pool.
@@ -106,7 +110,9 @@ export abstract class AbstractPool<
     protected readonly opts: PoolOptions<Worker>
   ) {
     if (!this.isMain()) {
-      throw new Error('Cannot start a pool from a worker!')
+      throw new Error(
+        'Cannot start a pool from a worker with the same type as the pool'
+      )
     }
     this.checkNumberOfWorkers(this.numberOfWorkers)
     this.checkFilePath(this.filePath)
@@ -187,7 +193,7 @@ export abstract class AbstractPool<
         )
       } else if (max === 0) {
         throw new RangeError(
-          'Cannot instantiate a dynamic pool with a pool size equal to zero'
+          'Cannot instantiate a dynamic pool with a maximum pool size equal to zero'
         )
       } else if (min === max) {
         throw new RangeError(
@@ -335,16 +341,20 @@ export abstract class AbstractPool<
           accumulator + workerNode.usage.tasks.executing,
         0
       ),
-      queuedTasks: this.workerNodes.reduce(
-        (accumulator, workerNode) =>
-          accumulator + workerNode.usage.tasks.queued,
-        0
-      ),
-      maxQueuedTasks: this.workerNodes.reduce(
-        (accumulator, workerNode) =>
-          accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
-        0
-      ),
+      ...(this.opts.enableTasksQueue === true && {
+        queuedTasks: this.workerNodes.reduce(
+          (accumulator, workerNode) =>
+            accumulator + workerNode.usage.tasks.queued,
+          0
+        )
+      }),
+      ...(this.opts.enableTasksQueue === true && {
+        maxQueuedTasks: this.workerNodes.reduce(
+          (accumulator, workerNode) =>
+            accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
+          0
+        )
+      }),
       failedTasks: this.workerNodes.reduce(
         (accumulator, workerNode) =>
           accumulator + workerNode.usage.tasks.failed,
@@ -356,14 +366,14 @@ export abstract class AbstractPool<
           minimum: round(
             Math.min(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.runTime?.minimum ?? Infinity
+                (workerNode) => workerNode.usage.runTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
             Math.max(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
+                (workerNode) => workerNode.usage.runTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -384,7 +394,7 @@ export abstract class AbstractPool<
             median: round(
               median(
                 this.workerNodes.map(
-                  workerNode => workerNode.usage.runTime?.median ?? 0
+                  (workerNode) => workerNode.usage.runTime?.median ?? 0
                 )
               )
             )
@@ -397,14 +407,14 @@ export abstract class AbstractPool<
           minimum: round(
             Math.min(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
+                (workerNode) => workerNode.usage.waitTime?.minimum ?? Infinity
               )
             )
           ),
           maximum: round(
             Math.max(
               ...this.workerNodes.map(
-                workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
+                (workerNode) => workerNode.usage.waitTime?.maximum ?? -Infinity
               )
             )
           ),
@@ -425,7 +435,7 @@ export abstract class AbstractPool<
             median: round(
               median(
                 this.workerNodes.map(
-                  workerNode => workerNode.usage.waitTime?.median ?? 0
+                  (workerNode) => workerNode.usage.waitTime?.median ?? 0
                 )
               )
             )
@@ -500,7 +510,9 @@ export abstract class AbstractPool<
    * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
    */
   private checkMessageWorkerId (message: MessageValue<Response>): void {
-    if (
+    if (message.workerId == null) {
+      throw new Error('Worker message received without worker id')
+    } else if (
       message.workerId != null &&
       this.getWorkerNodeKeyByWorkerId(message.workerId) === -1
     ) {
@@ -518,7 +530,7 @@ export abstract class AbstractPool<
    */
   private getWorkerNodeKeyByWorker (worker: Worker): number {
     return this.workerNodes.findIndex(
-      workerNode => workerNode.worker === worker
+      (workerNode) => workerNode.worker === worker
     )
   }
 
@@ -530,7 +542,7 @@ export abstract class AbstractPool<
    */
   private getWorkerNodeKeyByWorkerId (workerId: number): number {
     return this.workerNodes.findIndex(
-      workerNode => workerNode.info.id === workerId
+      (workerNode) => workerNode.info.id === workerId
     )
   }
 
@@ -549,7 +561,7 @@ export abstract class AbstractPool<
     }
     for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
       workerNode.resetUsage()
-      this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+      this.sendStatisticsMessageToWorker(workerNodeKey)
     }
   }
 
@@ -612,45 +624,93 @@ export abstract class AbstractPool<
   protected abstract get busy (): boolean
 
   /**
-   * Whether worker nodes are executing at least one task.
+   * Whether worker nodes are executing concurrently their tasks quota or not.
    *
    * @returns Worker nodes busyness boolean status.
    */
   protected internalBusy (): boolean {
-    return (
-      this.workerNodes.findIndex(workerNode => {
-        return workerNode.usage.tasks.executing === 0
-      }) === -1
-    )
+    if (this.opts.enableTasksQueue === true) {
+      return (
+        this.workerNodes.findIndex(
+          (workerNode) =>
+            workerNode.info.ready &&
+            workerNode.usage.tasks.executing <
+              (this.opts.tasksQueueOptions?.concurrency as number)
+        ) === -1
+      )
+    } else {
+      return (
+        this.workerNodes.findIndex(
+          (workerNode) =>
+            workerNode.info.ready && workerNode.usage.tasks.executing === 0
+        ) === -1
+      )
+    }
   }
 
   /** @inheritDoc */
-  public async execute (data?: Data, name?: string): Promise<Response> {
+  public listTaskFunctions (): string[] {
+    if (this.taskFunctions != null) {
+      return this.taskFunctions
+    } else {
+      return []
+    }
+  }
+
+  /** @inheritDoc */
+  public async execute (
+    data?: Data,
+    name?: string,
+    transferList?: TransferListItem[]
+  ): Promise<Response> {
     return await new Promise<Response>((resolve, reject) => {
+      if (name != null && typeof name !== 'string') {
+        reject(new TypeError('name argument must be a string'))
+      }
+      if (
+        name != null &&
+        typeof name === 'string' &&
+        name.trim().length === 0
+      ) {
+        reject(new TypeError('name argument must not be an empty string'))
+      }
+      if (
+        name != null &&
+        this.taskFunctions != null &&
+        !this.taskFunctions.includes(name)
+      ) {
+        reject(
+          new Error(`Task function '${name}' is not registered in the pool`)
+        )
+      }
+      if (transferList != null && !Array.isArray(transferList)) {
+        reject(new TypeError('transferList argument must be an array'))
+      }
       const timestamp = performance.now()
       const workerNodeKey = this.chooseWorkerNode()
       const task: Task<Data> = {
         name: name ?? DEFAULT_TASK_NAME,
         // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
         data: data ?? ({} as Data),
+        transferList,
         timestamp,
         workerId: this.getWorkerInfo(workerNodeKey).id as number,
-        id: randomUUID()
+        taskId: randomUUID()
       }
-      this.promiseResponseMap.set(task.id as string, {
+      this.promiseResponseMap.set(task.taskId as string, {
         resolve,
         reject,
         workerNodeKey
       })
       if (
-        this.opts.enableTasksQueue === true &&
-        (this.busy ||
-          this.workerNodes[workerNodeKey].usage.tasks.executing >=
+        this.opts.enableTasksQueue === false ||
+        (this.opts.enableTasksQueue === true &&
+          this.workerNodes[workerNodeKey].usage.tasks.executing <
             (this.opts.tasksQueueOptions?.concurrency as number))
       ) {
-        this.enqueueTask(workerNodeKey, task)
-      } else {
         this.executeTask(workerNodeKey, task)
+      } else {
+        this.enqueueTask(workerNodeKey, task)
       }
       this.checkAndEmitEvents()
     })
@@ -659,18 +719,27 @@ export abstract class AbstractPool<
   /** @inheritDoc */
   public async destroy (): Promise<void> {
     await Promise.all(
-      this.workerNodes.map(async (workerNode, workerNodeKey) => {
-        this.flushTasksQueue(workerNodeKey)
-        // FIXME: wait for tasks to be finished
-        const workerExitPromise = new Promise<void>(resolve => {
-          workerNode.worker.on('exit', () => {
-            resolve()
-          })
-        })
+      this.workerNodes.map(async (_, workerNodeKey) => {
         await this.destroyWorkerNode(workerNodeKey)
-        await workerExitPromise
       })
     )
+    this.emitter?.emit(PoolEvents.destroy)
+  }
+
+  protected async sendKillMessageToWorker (
+    workerNodeKey: number,
+    workerId: number
+  ): Promise<void> {
+    await new Promise<void>((resolve, reject) => {
+      this.registerWorkerMessageListener(workerNodeKey, (message) => {
+        if (message.kill === 'success') {
+          resolve()
+        } else if (message.kill === 'failure') {
+          reject(new Error(`Worker ${workerId} kill message handling failed`))
+        }
+      })
+      this.sendToWorker(workerNodeKey, { kill: true, workerId })
+    })
   }
 
   /**
@@ -678,9 +747,7 @@ export abstract class AbstractPool<
    *
    * @param workerNodeKey - The worker node key.
    */
-  protected abstract destroyWorkerNode (
-    workerNodeKey: number
-  ): void | Promise<void>
+  protected abstract destroyWorkerNode (workerNodeKey: number): Promise<void>
 
   /**
    * Setup hook to execute code before worker nodes are created in the abstract constructor.
@@ -845,10 +912,12 @@ export abstract class AbstractPool<
    *
    * @param workerNodeKey - The worker node key.
    * @param message - The message.
+   * @param transferList - The optional array of transferable objects.
    */
   protected abstract sendToWorker (
     workerNodeKey: number,
-    message: MessageValue<Data>
+    message: MessageValue<Data>,
+    transferList?: TransferListItem[]
   ): void
 
   /**
@@ -866,9 +935,10 @@ export abstract class AbstractPool<
   protected createAndSetupWorkerNode (): number {
     const worker = this.createWorker()
 
+    worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
     worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
     worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
-    worker.on('error', error => {
+    worker.on('error', (error) => {
       const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
       const workerInfo = this.getWorkerInfo(workerNodeKey)
       workerInfo.ready = false
@@ -885,7 +955,6 @@ export abstract class AbstractPool<
         this.redistributeQueuedTasks(workerNodeKey)
       }
     })
-    worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
     worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
     worker.once('exit', () => {
       this.removeWorkerNode(worker)
@@ -905,31 +974,24 @@ export abstract class AbstractPool<
    */
   protected createAndSetupDynamicWorkerNode (): number {
     const workerNodeKey = this.createAndSetupWorkerNode()
-    this.registerWorkerMessageListener(workerNodeKey, message => {
+    this.registerWorkerMessageListener(workerNodeKey, (message) => {
       const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
         message.workerId
       )
       const workerUsage = this.workerNodes[localWorkerNodeKey].usage
+      // Kill message received from worker
       if (
         isKillBehavior(KillBehaviors.HARD, message.kill) ||
-        (message.kill != null &&
+        (isKillBehavior(KillBehaviors.SOFT, message.kill) &&
           ((this.opts.enableTasksQueue === false &&
             workerUsage.tasks.executing === 0) ||
             (this.opts.enableTasksQueue === true &&
               workerUsage.tasks.executing === 0 &&
               this.tasksQueueSize(localWorkerNodeKey) === 0)))
       ) {
-        // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
-        const destroyWorkerNodeBounded = this.destroyWorkerNode.bind(this)
-        if (isAsyncFunction(destroyWorkerNodeBounded)) {
-          (
-            destroyWorkerNodeBounded as (workerNodeKey: number) => Promise<void>
-          )(localWorkerNodeKey).catch(EMPTY_FUNCTION)
-        } else {
-          (destroyWorkerNodeBounded as (workerNodeKey: number) => void)(
-            localWorkerNodeKey
-          )
-        }
+        this.destroyWorkerNode(localWorkerNodeKey).catch((error) => {
+          this.emitter?.emit(PoolEvents.error, error)
+        })
       }
     })
     const workerInfo = this.getWorkerInfo(workerNodeKey)
@@ -968,8 +1030,8 @@ export abstract class AbstractPool<
     this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
     // Send the startup message to worker.
     this.sendStartupMessageToWorker(workerNodeKey)
-    // Send the worker statistics message to worker.
-    this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+    // Send the statistics message to worker.
+    this.sendStatisticsMessageToWorker(workerNodeKey)
   }
 
   /**
@@ -980,11 +1042,11 @@ export abstract class AbstractPool<
   protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
 
   /**
-   * Sends the worker statistics message to worker given its worker node key.
+   * Sends the statistics message to worker given its worker node key.
    *
    * @param workerNodeKey - The worker node key.
    */
-  private sendWorkerStatisticsMessageToWorker (workerNodeKey: number): void {
+  private sendStatisticsMessageToWorker (workerNodeKey: number): void {
     this.sendToWorker(workerNodeKey, {
       statistics: {
         runTime:
@@ -1047,14 +1109,17 @@ export abstract class AbstractPool<
    * @returns The listener function to execute when a message is received from a worker.
    */
   protected workerListener (): (message: MessageValue<Response>) => void {
-    return message => {
+    return (message) => {
       this.checkMessageWorkerId(message)
       if (message.ready != null) {
-        // Worker ready response received
+        // Worker ready response received from worker
         this.handleWorkerReadyResponse(message)
-      } else if (message.id != null) {
-        // Task execution response received
+      } else if (message.taskId != null) {
+        // Task execution response received from worker
         this.handleTaskExecutionResponse(message)
+      } else if (message.taskFunctions != null) {
+        // Task functions message received from worker
+        this.taskFunctions = message.taskFunctions
       }
     }
   }
@@ -1069,7 +1134,9 @@ export abstract class AbstractPool<
   }
 
   private handleTaskExecutionResponse (message: MessageValue<Response>): void {
-    const promiseResponse = this.promiseResponseMap.get(message.id as string)
+    const promiseResponse = this.promiseResponseMap.get(
+      message.taskId as string
+    )
     if (promiseResponse != null) {
       if (message.taskError != null) {
         this.emitter?.emit(PoolEvents.taskError, message.taskError)
@@ -1079,7 +1146,7 @@ export abstract class AbstractPool<
       }
       const workerNodeKey = promiseResponse.workerNodeKey
       this.afterTaskExecutionHook(workerNodeKey, message)
-      this.promiseResponseMap.delete(message.id as string)
+      this.promiseResponseMap.delete(message.taskId as string)
       if (
         this.opts.enableTasksQueue === true &&
         this.tasksQueueSize(workerNodeKey) > 0 &&
@@ -1158,7 +1225,7 @@ export abstract class AbstractPool<
    */
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
-    this.sendToWorker(workerNodeKey, task)
+    this.sendToWorker(workerNodeKey, task, task.transferList)
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
@@ -1173,7 +1240,7 @@ export abstract class AbstractPool<
     return this.workerNodes[workerNodeKey].tasksQueueSize()
   }
 
-  private flushTasksQueue (workerNodeKey: number): void {
+  protected flushTasksQueue (workerNodeKey: number): void {
     while (this.tasksQueueSize(workerNodeKey) > 0) {
       this.executeTask(
         workerNodeKey,