src/pools/worker-node.ts

   1 import { MessageChannel } from 'node:worker_threads'
   2 import { CircularArray } from '../circular-array'
   3 import { Queue } from '../queue'
   4 import type { Task } from '../utility-types'
   5 import { DEFAULT_TASK_NAME } from '../utils'
   6 import {
   7   type IWorker,
   8   type IWorkerNode,
   9   type WorkerInfo,
  10   type WorkerType,
  11   WorkerTypes,
  12   type WorkerUsage
  13 } from './worker'
  14
  15 /**
  16  * Worker node.
  17  *
  18  * @typeParam Worker - Type of worker.
  19  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  20  */
  21 export class WorkerNode<Worker extends IWorker, Data = unknown>
  22 implements IWorkerNode<Worker, Data> {
  23   /** @inheritdoc */
  24   public readonly worker: Worker
  25   /** @inheritdoc */
  26   public readonly info: WorkerInfo
  27   /** @inheritdoc */
  28   public messageChannel?: MessageChannel
  29   /** @inheritdoc */
  30   public usage: WorkerUsage
  31   private readonly taskFunctionsUsage: Map<string, WorkerUsage>
  32   private readonly tasksQueue: Queue<Task<Data>>
  33   private readonly tasksQueueBackPressureSize: number
  34
  35   /**
  36    * Constructs a new worker node.
  37    *
  38    * @param worker - The worker.
  39    * @param workerType - The worker type.
  40    * @param poolMaxSize - The pool maximum size.
  41    */
  42   constructor (worker: Worker, workerType: WorkerType, poolMaxSize: number) {
  43     if (worker == null) {
  44       throw new Error('Cannot construct a worker node without a worker')
  45     }
  46     if (workerType == null) {
  47       throw new Error('Cannot construct a worker node without a worker type')
  48     }
  49     if (poolMaxSize == null) {
  50       throw new Error(
  51         'Cannot construct a worker node without a pool maximum size'
  52       )
  53     }
  54     if (isNaN(poolMaxSize)) {
  55       throw new Error(
  56         'Cannot construct a worker node with a NaN pool maximum size'
  57       )
  58     }
  59     this.worker = worker
  60     this.info = this.initWorkerInfo(worker, workerType)
  61     if (workerType === WorkerTypes.thread) {
  62       this.messageChannel = new MessageChannel()
  63     }
  64     this.usage = this.initWorkerUsage()
  65     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  66     this.tasksQueue = new Queue<Task<Data>>()
  67     this.tasksQueueBackPressureSize = Math.pow(poolMaxSize, 2)
  68   }
  69
  70   /** @inheritdoc */
  71   public tasksQueueSize (): number {
  72     return this.tasksQueue.size
  73   }
  74
  75   /**
  76    * Tasks queue maximum size.
  77    *
  78    * @returns The tasks queue maximum size.
  79    */
  80   private tasksQueueMaxSize (): number {
  81     return this.tasksQueue.maxSize
  82   }
  83
  84   /** @inheritdoc */
  85   public enqueueTask (task: Task<Data>): number {
  86     return this.tasksQueue.enqueue(task)
  87   }
  88
  89   /** @inheritdoc */
  90   public dequeueTask (): Task<Data> | undefined {
  91     return this.tasksQueue.dequeue()
  92   }
  93
  94   /** @inheritdoc */
  95   public clearTasksQueue (): void {
  96     this.tasksQueue.clear()
  97   }
  98
  99   /** @inheritdoc */
 100   public hasBackPressure (): boolean {
 101     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 102   }
 103
 104   /** @inheritdoc */
 105   public resetUsage (): void {
 106     this.usage = this.initWorkerUsage()
 107     this.taskFunctionsUsage.clear()
 108   }
 109
 110   /** @inheritdoc */
 111   public closeChannel (): void {
 112     if (this.messageChannel != null) {
 113       this.messageChannel?.port1.unref()
 114       this.messageChannel?.port2.unref()
 115       this.messageChannel?.port1.close()
 116       this.messageChannel?.port2.close()
 117       delete this.messageChannel
 118     }
 119   }
 120
 121   /** @inheritdoc */
 122   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 123     if (!Array.isArray(this.info.taskFunctions)) {
 124       throw new Error(
 125         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 126       )
 127     }
 128     if (
 129       Array.isArray(this.info.taskFunctions) &&
 130       this.info.taskFunctions.length < 3
 131     ) {
 132       throw new Error(
 133         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 134       )
 135     }
 136     if (name === DEFAULT_TASK_NAME) {
 137       name = this.info.taskFunctions[1]
 138     }
 139     if (!this.taskFunctionsUsage.has(name)) {
 140       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 141     }
 142     return this.taskFunctionsUsage.get(name)
 143   }
 144
 145   private initWorkerInfo (worker: Worker, workerType: WorkerType): WorkerInfo {
 146     return {
 147       id: this.getWorkerId(worker, workerType),
 148       type: workerType,
 149       dynamic: false,
 150       ready: false
 151     }
 152   }
 153
 154   private initWorkerUsage (): WorkerUsage {
 155     const getTasksQueueSize = (): number => {
 156       return this.tasksQueueSize()
 157     }
 158     const getTasksQueueMaxSize = (): number => {
 159       return this.tasksQueueMaxSize()
 160     }
 161     return {
 162       tasks: {
 163         executed: 0,
 164         executing: 0,
 165         get queued (): number {
 166           return getTasksQueueSize()
 167         },
 168         get maxQueued (): number {
 169           return getTasksQueueMaxSize()
 170         },
 171         failed: 0
 172       },
 173       runTime: {
 174         history: new CircularArray()
 175       },
 176       waitTime: {
 177         history: new CircularArray()
 178       },
 179       elu: {
 180         idle: {
 181           history: new CircularArray()
 182         },
 183         active: {
 184           history: new CircularArray()
 185         }
 186       }
 187     }
 188   }
 189
 190   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 191     const getTaskQueueSize = (): number => {
 192       let taskQueueSize = 0
 193       for (const task of this.tasksQueue) {
 194         if (task.name === name) {
 195           ++taskQueueSize
 196         }
 197       }
 198       return taskQueueSize
 199     }
 200     return {
 201       tasks: {
 202         executed: 0,
 203         executing: 0,
 204         get queued (): number {
 205           return getTaskQueueSize()
 206         },
 207         failed: 0
 208       },
 209       runTime: {
 210         history: new CircularArray()
 211       },
 212       waitTime: {
 213         history: new CircularArray()
 214       },
 215       elu: {
 216         idle: {
 217           history: new CircularArray()
 218         },
 219         active: {
 220           history: new CircularArray()
 221         }
 222       }
 223     }
 224   }
 225
 226   /**
 227    * Gets the worker id.
 228    *
 229    * @param worker - The worker.
 230    * @param workerType - The worker type.
 231    * @returns The worker id.
 232    */
 233   private getWorkerId (
 234     worker: Worker,
 235     workerType: WorkerType
 236   ): number | undefined {
 237     if (workerType === WorkerTypes.thread) {
 238       return worker.threadId
 239     } else if (workerType === WorkerTypes.cluster) {
 240       return worker.id
 241     }
 242   }
 243 }