fix: fix back pressure detection
[poolifier.git] / src / pools / abstract-pool.ts
index 6d71e87e34378abe5c75ad1c1806eacaad979a3b..dceef6decb534f083510d90a947a05861c2ec2df 100644 (file)
@@ -92,10 +92,6 @@ 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.
@@ -122,7 +118,10 @@ export abstract class AbstractPool<
     this.executeTask = this.executeTask.bind(this)
     this.enqueueTask = this.enqueueTask.bind(this)
     this.dequeueTask = this.dequeueTask.bind(this)
-    this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
+    this.checkAndEmitTaskExecutionEvents =
+      this.checkAndEmitTaskExecutionEvents.bind(this)
+    this.checkAndEmitTaskQueuingEvents =
+      this.checkAndEmitTaskQueuingEvents.bind(this)
 
     if (this.opts.enableEvents === true) {
       this.emitter = new PoolEmitter()
@@ -208,9 +207,10 @@ export abstract class AbstractPool<
       this.opts.workerChoiceStrategy =
         opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
       this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
-      this.opts.workerChoiceStrategyOptions =
-        opts.workerChoiceStrategyOptions ??
-        DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+      this.opts.workerChoiceStrategyOptions = {
+        ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+        ...opts.workerChoiceStrategyOptions
+      }
       this.checkValidWorkerChoiceStrategyOptions(
         this.opts.workerChoiceStrategyOptions
       )
@@ -248,6 +248,22 @@ export abstract class AbstractPool<
         'Invalid worker choice strategy options: must be a plain object'
       )
     }
+    if (
+      workerChoiceStrategyOptions.choiceRetries != null &&
+      !Number.isSafeInteger(workerChoiceStrategyOptions.choiceRetries)
+    ) {
+      throw new TypeError(
+        'Invalid worker choice strategy options: choice retries must be an integer'
+      )
+    }
+    if (
+      workerChoiceStrategyOptions.choiceRetries != null &&
+      workerChoiceStrategyOptions.choiceRetries <= 0
+    ) {
+      throw new RangeError(
+        `Invalid worker choice strategy options: choice retries '${workerChoiceStrategyOptions.choiceRetries}' must be greater than zero`
+      )
+    }
     if (
       workerChoiceStrategyOptions.weights != null &&
       Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
@@ -287,7 +303,7 @@ export abstract class AbstractPool<
       tasksQueueOptions.concurrency <= 0
     ) {
       throw new Error(
-        `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
+        `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}' is a negative integer or zero`
       )
     }
   }
@@ -355,6 +371,9 @@ export abstract class AbstractPool<
           0
         )
       }),
+      ...(this.opts.enableTasksQueue === true && {
+        backPressure: this.hasBackPressure()
+      }),
       failedTasks: this.workerNodes.reduce(
         (accumulator, workerNode) =>
           accumulator + workerNode.usage.tasks.failed,
@@ -570,7 +589,10 @@ export abstract class AbstractPool<
     workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
   ): void {
     this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
-    this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+    this.opts.workerChoiceStrategyOptions = {
+      ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+      ...workerChoiceStrategyOptions
+    }
     this.workerChoiceStrategyContext.setOptions(
       this.opts.workerChoiceStrategyOptions
     )
@@ -650,11 +672,15 @@ export abstract class AbstractPool<
 
   /** @inheritDoc */
   public listTaskFunctions (): string[] {
-    if (this.taskFunctions != null) {
-      return this.taskFunctions
-    } else {
-      return []
+    for (const workerNode of this.workerNodes) {
+      if (
+        Array.isArray(workerNode.info.taskFunctions) &&
+        workerNode.info.taskFunctions.length > 0
+      ) {
+        return workerNode.info.taskFunctions
+      }
     }
+    return []
   }
 
   /** @inheritDoc */
@@ -674,27 +700,28 @@ export abstract class AbstractPool<
       ) {
         reject(new TypeError('name argument must not be an empty string'))
       }
+      if (transferList != null && !Array.isArray(transferList)) {
+        reject(new TypeError('transferList argument must be an array'))
+      }
+      const timestamp = performance.now()
+      const workerNodeKey = this.chooseWorkerNode()
+      const workerInfo = this.getWorkerInfo(workerNodeKey)
       if (
         name != null &&
-        this.taskFunctions != null &&
-        !this.taskFunctions.includes(name)
+        Array.isArray(workerInfo.taskFunctions) &&
+        !workerInfo.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,
+        workerId: workerInfo.id as number,
         taskId: randomUUID()
       }
       this.promiseResponseMap.set(task.taskId as string, {
@@ -712,7 +739,6 @@ export abstract class AbstractPool<
       } else {
         this.enqueueTask(workerNodeKey, task)
       }
-      this.checkAndEmitEvents()
     })
   }
 
@@ -778,11 +804,13 @@ export abstract class AbstractPool<
     const workerUsage = this.workerNodes[workerNodeKey].usage
     ++workerUsage.tasks.executing
     this.updateWaitTimeWorkerUsage(workerUsage, task)
-    const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
-      task.name as string
-    ) as WorkerUsage
-    ++taskWorkerUsage.tasks.executing
-    this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
+    if (this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey)) {
+      const taskFunctionWorkerUsage = this.workerNodes[
+        workerNodeKey
+      ].getTaskFunctionWorkerUsage(task.name as string) as WorkerUsage
+      ++taskFunctionWorkerUsage.tasks.executing
+      this.updateWaitTimeWorkerUsage(taskFunctionWorkerUsage, task)
+    }
   }
 
   /**
@@ -800,12 +828,30 @@ export abstract class AbstractPool<
     this.updateTaskStatisticsWorkerUsage(workerUsage, message)
     this.updateRunTimeWorkerUsage(workerUsage, message)
     this.updateEluWorkerUsage(workerUsage, message)
-    const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
-      message.taskPerformance?.name ?? DEFAULT_TASK_NAME
-    ) as WorkerUsage
-    this.updateTaskStatisticsWorkerUsage(taskWorkerUsage, message)
-    this.updateRunTimeWorkerUsage(taskWorkerUsage, message)
-    this.updateEluWorkerUsage(taskWorkerUsage, message)
+    if (this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey)) {
+      const taskFunctionWorkerUsage = this.workerNodes[
+        workerNodeKey
+      ].getTaskFunctionWorkerUsage(
+        message.taskPerformance?.name ?? DEFAULT_TASK_NAME
+      ) as WorkerUsage
+      this.updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage, message)
+      this.updateRunTimeWorkerUsage(taskFunctionWorkerUsage, message)
+      this.updateEluWorkerUsage(taskFunctionWorkerUsage, message)
+    }
+  }
+
+  /**
+   * Whether the worker node shall update its task function worker usage or not.
+   *
+   * @param workerNodeKey - The worker node key.
+   * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
+   */
+  private shallUpdateTaskFunctionWorkerUsage (workerNodeKey: number): boolean {
+    const workerInfo = this.getWorkerInfo(workerNodeKey)
+    return (
+      Array.isArray(workerInfo.taskFunctions) &&
+      workerInfo.taskFunctions.length > 2
+    )
   }
 
   private updateTaskStatisticsWorkerUsage (
@@ -813,7 +859,19 @@ export abstract class AbstractPool<
     message: MessageValue<Response>
   ): void {
     const workerTaskStatistics = workerUsage.tasks
-    --workerTaskStatistics.executing
+    if (
+      workerTaskStatistics.executing != null &&
+      workerTaskStatistics.executing > 0
+    ) {
+      --workerTaskStatistics.executing
+    } else if (
+      workerTaskStatistics.executing != null &&
+      workerTaskStatistics.executing < 0
+    ) {
+      throw new Error(
+        'Worker usage statistic for tasks executing cannot be negative'
+      )
+    }
     if (message.taskError == null) {
       ++workerTaskStatistics.executed
     } else {
@@ -1111,7 +1169,7 @@ export abstract class AbstractPool<
   protected workerListener (): (message: MessageValue<Response>) => void {
     return (message) => {
       this.checkMessageWorkerId(message)
-      if (message.ready != null) {
+      if (message.ready != null && message.taskFunctions != null) {
         // Worker ready response received from worker
         this.handleWorkerReadyResponse(message)
       } else if (message.taskId != null) {
@@ -1119,7 +1177,9 @@ export abstract class AbstractPool<
         this.handleTaskExecutionResponse(message)
       } else if (message.taskFunctions != null) {
         // Task functions message received from worker
-        this.taskFunctions = message.taskFunctions
+        this.getWorkerInfo(
+          this.getWorkerNodeKeyByWorkerId(message.workerId)
+        ).taskFunctions = message.taskFunctions
       }
     }
   }
@@ -1128,28 +1188,29 @@ export abstract class AbstractPool<
     if (message.ready === false) {
       throw new Error(`Worker ${message.workerId} failed to initialize`)
     }
-    this.getWorkerInfo(
+    const workerInfo = this.getWorkerInfo(
       this.getWorkerNodeKeyByWorkerId(message.workerId)
-    ).ready = message.ready as boolean
+    )
+    workerInfo.ready = message.ready as boolean
+    workerInfo.taskFunctions = message.taskFunctions
     if (this.emitter != null && this.ready) {
       this.emitter.emit(PoolEvents.ready, this.info)
     }
   }
 
   private handleTaskExecutionResponse (message: MessageValue<Response>): void {
-    const promiseResponse = this.promiseResponseMap.get(
-      message.taskId as string
-    )
+    const { taskId, taskError, data } = message
+    const promiseResponse = this.promiseResponseMap.get(taskId as string)
     if (promiseResponse != null) {
-      if (message.taskError != null) {
-        this.emitter?.emit(PoolEvents.taskError, message.taskError)
-        promiseResponse.reject(message.taskError.message)
+      if (taskError != null) {
+        this.emitter?.emit(PoolEvents.taskError, taskError)
+        promiseResponse.reject(taskError.message)
       } else {
-        promiseResponse.resolve(message.data as Response)
+        promiseResponse.resolve(data as Response)
       }
       const workerNodeKey = promiseResponse.workerNodeKey
       this.afterTaskExecutionHook(workerNodeKey, message)
-      this.promiseResponseMap.delete(message.taskId as string)
+      this.promiseResponseMap.delete(taskId as string)
       if (
         this.opts.enableTasksQueue === true &&
         this.tasksQueueSize(workerNodeKey) > 0 &&
@@ -1165,7 +1226,7 @@ export abstract class AbstractPool<
     }
   }
 
-  private checkAndEmitEvents (): void {
+  private checkAndEmitTaskExecutionEvents (): void {
     if (this.emitter != null) {
       if (this.busy) {
         this.emitter.emit(PoolEvents.busy, this.info)
@@ -1176,6 +1237,12 @@ export abstract class AbstractPool<
     }
   }
 
+  private checkAndEmitTaskQueuingEvents (): void {
+    if (this.hasBackPressure()) {
+      this.emitter?.emit(PoolEvents.backPressure, this.info)
+    }
+  }
+
   /**
    * Gets the worker information given its worker node key.
    *
@@ -1194,7 +1261,11 @@ export abstract class AbstractPool<
    * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
    */
   private addWorkerNode (worker: Worker): number {
-    const workerNode = new WorkerNode<Worker, Data>(worker, this.worker)
+    const workerNode = new WorkerNode<Worker, Data>(
+      worker,
+      this.worker,
+      this.maxSize
+    )
     // Flag the worker node as ready at pool startup.
     if (this.starting) {
       workerNode.info.ready = true
@@ -1202,7 +1273,7 @@ export abstract class AbstractPool<
     this.workerNodes.push(workerNode)
     const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
     if (workerNodeKey === -1) {
-      throw new Error('Worker node not found')
+      throw new Error('Worker node added not found')
     }
     return workerNodeKey
   }
@@ -1220,6 +1291,23 @@ export abstract class AbstractPool<
     }
   }
 
+  /** @inheritDoc */
+  public hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+    return (
+      this.opts.enableTasksQueue === true &&
+      this.workerNodes[workerNodeKey].hasBackPressure()
+    )
+  }
+
+  private hasBackPressure (): boolean {
+    return (
+      this.opts.enableTasksQueue === true &&
+      this.workerNodes.findIndex(
+        (workerNode) => !workerNode.hasBackPressure()
+      ) === -1
+    )
+  }
+
   /**
    * Executes the given task on the worker given its worker node key.
    *
@@ -1229,10 +1317,13 @@ export abstract class AbstractPool<
   private executeTask (workerNodeKey: number, task: Task<Data>): void {
     this.beforeTaskExecutionHook(workerNodeKey, task)
     this.sendToWorker(workerNodeKey, task, task.transferList)
+    this.checkAndEmitTaskExecutionEvents()
   }
 
   private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
-    return this.workerNodes[workerNodeKey].enqueueTask(task)
+    const tasksQueueSize = this.workerNodes[workerNodeKey].enqueueTask(task)
+    this.checkAndEmitTaskQueuingEvents()
+    return tasksQueueSize
   }
 
   private dequeueTask (workerNodeKey: number): Task<Data> | undefined {