src/pools/worker-node.ts

   1 import { MessageChannel } from 'node:worker_threads'
   2 import { CircularArray } from '../circular-array'
   3 import type { Task } from '../utility-types'
   4 import { DEFAULT_TASK_NAME } from '../utils'
   5 import { Deque } from '../deque'
   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   /** @inheritdoc */
  32   public tasksQueueBackPressureSize: number
  33   /** @inheritdoc */
  34   public onBackPressure?: (workerId: number) => void
  35   private readonly taskFunctionsUsage: Map<string, WorkerUsage>
  36   private readonly tasksQueue: Deque<Task<Data>>
  37
  38   /**
  39    * Constructs a new worker node.
  40    *
  41    * @param worker - The worker.
  42    * @param workerType - The worker type.
  43    * @param tasksQueueBackPressureSize - The tasks queue back pressure size.
  44    */
  45   constructor (
  46     worker: Worker,
  47     workerType: WorkerType,
  48     tasksQueueBackPressureSize: number
  49   ) {
  50     if (worker == null) {
  51       throw new TypeError('Cannot construct a worker node without a worker')
  52     }
  53     if (workerType == null) {
  54       throw new TypeError(
  55         'Cannot construct a worker node without a worker type'
  56       )
  57     }
  58     if (tasksQueueBackPressureSize == null) {
  59       throw new TypeError(
  60         'Cannot construct a worker node without a tasks queue back pressure size'
  61       )
  62     }
  63     if (!Number.isSafeInteger(tasksQueueBackPressureSize)) {
  64       throw new TypeError(
  65         'Cannot construct a worker node with a tasks queue back pressure size that is not an integer'
  66       )
  67     }
  68     this.worker = worker
  69     this.info = this.initWorkerInfo(worker, workerType)
  70     if (workerType === WorkerTypes.thread) {
  71       this.messageChannel = new MessageChannel()
  72     }
  73     this.usage = this.initWorkerUsage()
  74     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  75     this.tasksQueue = new Deque<Task<Data>>()
  76     this.tasksQueueBackPressureSize = tasksQueueBackPressureSize
  77   }
  78
  79   /** @inheritdoc */
  80   public tasksQueueSize (): number {
  81     return this.tasksQueue.size
  82   }
  83
  84   /**
  85    * Tasks queue maximum size.
  86    *
  87    * @returns The tasks queue maximum size.
  88    */
  89   private tasksQueueMaxSize (): number {
  90     return this.tasksQueue.maxSize
  91   }
  92
  93   /** @inheritdoc */
  94   public enqueueTask (task: Task<Data>): number {
  95     const tasksQueueSize = this.tasksQueue.push(task)
  96     if (this.onBackPressure != null && this.hasBackPressure()) {
  97       this.once(this.onBackPressure)(this.info.id as number)
  98     }
  99     return tasksQueueSize
 100   }
 101
 102   /** @inheritdoc */
 103   public unshiftTask (task: Task<Data>): number {
 104     const tasksQueueSize = this.tasksQueue.unshift(task)
 105     if (this.onBackPressure != null && this.hasBackPressure()) {
 106       this.once(this.onBackPressure)(this.info.id as number)
 107     }
 108     return tasksQueueSize
 109   }
 110
 111   /** @inheritdoc */
 112   public dequeueTask (): Task<Data> | undefined {
 113     return this.tasksQueue.shift()
 114   }
 115
 116   /** @inheritdoc */
 117   public popTask (): Task<Data> | undefined {
 118     return this.tasksQueue.pop()
 119   }
 120
 121   /** @inheritdoc */
 122   public clearTasksQueue (): void {
 123     this.tasksQueue.clear()
 124   }
 125
 126   /** @inheritdoc */
 127   public hasBackPressure (): boolean {
 128     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 129   }
 130
 131   /** @inheritdoc */
 132   public resetUsage (): void {
 133     this.usage = this.initWorkerUsage()
 134     this.taskFunctionsUsage.clear()
 135   }
 136
 137   /** @inheritdoc */
 138   public closeChannel (): void {
 139     if (this.messageChannel != null) {
 140       this.messageChannel?.port1.unref()
 141       this.messageChannel?.port2.unref()
 142       this.messageChannel?.port1.close()
 143       this.messageChannel?.port2.close()
 144       delete this.messageChannel
 145     }
 146   }
 147
 148   /** @inheritdoc */
 149   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 150     if (!Array.isArray(this.info.taskFunctions)) {
 151       throw new Error(
 152         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 153       )
 154     }
 155     if (
 156       Array.isArray(this.info.taskFunctions) &&
 157       this.info.taskFunctions.length < 3
 158     ) {
 159       throw new Error(
 160         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 161       )
 162     }
 163     if (name === DEFAULT_TASK_NAME) {
 164       name = this.info.taskFunctions[1]
 165     }
 166     if (!this.taskFunctionsUsage.has(name)) {
 167       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 168     }
 169     return this.taskFunctionsUsage.get(name)
 170   }
 171
 172   private initWorkerInfo (worker: Worker, workerType: WorkerType): WorkerInfo {
 173     return {
 174       id: this.getWorkerId(worker, workerType),
 175       type: workerType,
 176       dynamic: false,
 177       ready: false
 178     }
 179   }
 180
 181   private initWorkerUsage (): WorkerUsage {
 182     const getTasksQueueSize = (): number => {
 183       return this.tasksQueueSize()
 184     }
 185     const getTasksQueueMaxSize = (): number => {
 186       return this.tasksQueueMaxSize()
 187     }
 188     return {
 189       tasks: {
 190         executed: 0,
 191         executing: 0,
 192         get queued (): number {
 193           return getTasksQueueSize()
 194         },
 195         get maxQueued (): number {
 196           return getTasksQueueMaxSize()
 197         },
 198         failed: 0
 199       },
 200       runTime: {
 201         history: new CircularArray()
 202       },
 203       waitTime: {
 204         history: new CircularArray()
 205       },
 206       elu: {
 207         idle: {
 208           history: new CircularArray()
 209         },
 210         active: {
 211           history: new CircularArray()
 212         }
 213       }
 214     }
 215   }
 216
 217   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 218     const getTaskFunctionQueueSize = (): number => {
 219       let taskFunctionQueueSize = 0
 220       for (const task of this.tasksQueue) {
 221         if (
 222           (task.name === DEFAULT_TASK_NAME &&
 223             name === (this.info.taskFunctions as string[])[1]) ||
 224           (task.name !== DEFAULT_TASK_NAME && name === task.name)
 225         ) {
 226           ++taskFunctionQueueSize
 227         }
 228       }
 229       return taskFunctionQueueSize
 230     }
 231     return {
 232       tasks: {
 233         executed: 0,
 234         executing: 0,
 235         get queued (): number {
 236           return getTaskFunctionQueueSize()
 237         },
 238         failed: 0
 239       },
 240       runTime: {
 241         history: new CircularArray()
 242       },
 243       waitTime: {
 244         history: new CircularArray()
 245       },
 246       elu: {
 247         idle: {
 248           history: new CircularArray()
 249         },
 250         active: {
 251           history: new CircularArray()
 252         }
 253       }
 254     }
 255   }
 256
 257   /**
 258    * Gets the worker id.
 259    *
 260    * @param worker - The worker.
 261    * @param workerType - The worker type.
 262    * @returns The worker id.
 263    */
 264   private getWorkerId (
 265     worker: Worker,
 266     workerType: WorkerType
 267   ): number | undefined {
 268     if (workerType === WorkerTypes.thread) {
 269       return worker.threadId
 270     } else if (workerType === WorkerTypes.cluster) {
 271       return worker.id
 272     }
 273   }
 274
 275   /**
 276    * Executes a function once at a time.
 277    */
 278
 279   private once (
 280     // eslint-disable-next-line @typescript-eslint/no-explicit-any
 281     fn: (...args: any[]) => void,
 282     context = this
 283     // eslint-disable-next-line @typescript-eslint/no-explicit-any
 284   ): (...args: any[]) => void {
 285     let called = false
 286     // eslint-disable-next-line @typescript-eslint/no-explicit-any
 287     return function (...args: any[]): void {
 288       if (!called) {
 289         called = true
 290         fn.apply(context, args)
 291         called = false
 292       }
 293     }
 294   }
 295 }