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, once } 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   /** @inheritdoc */
  36   public onEmptyQueue?: (workerId: number) => void
  37   private readonly taskFunctionsUsage: Map<string, WorkerUsage>
  38   private readonly tasksQueue: Deque<Task<Data>>
  39
  40   /**
  41    * Constructs a new worker node.
  42    *
  43    * @param worker - The worker.
  44    * @param workerType - The worker type.
  45    * @param tasksQueueBackPressureSize - The tasks queue back pressure size.
  46    */
  47   constructor (
  48     worker: Worker,
  49     workerType: WorkerType,
  50     tasksQueueBackPressureSize: number
  51   ) {
  52     if (worker == null) {
  53       throw new TypeError('Cannot construct a worker node without a worker')
  54     }
  55     if (workerType == null) {
  56       throw new TypeError(
  57         'Cannot construct a worker node without a worker type'
  58       )
  59     }
  60     if (tasksQueueBackPressureSize == null) {
  61       throw new TypeError(
  62         'Cannot construct a worker node without a tasks queue back pressure size'
  63       )
  64     }
  65     if (!Number.isSafeInteger(tasksQueueBackPressureSize)) {
  66       throw new TypeError(
  67         'Cannot construct a worker node with a tasks queue back pressure size that is not an integer'
  68       )
  69     }
  70     this.worker = worker
  71     this.info = this.initWorkerInfo(worker, workerType)
  72     if (workerType === WorkerTypes.thread) {
  73       this.messageChannel = new MessageChannel()
  74     }
  75     this.usage = this.initWorkerUsage()
  76     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  77     this.tasksQueue = new Deque<Task<Data>>()
  78     this.tasksQueueBackPressureSize = tasksQueueBackPressureSize
  79   }
  80
  81   /** @inheritdoc */
  82   public tasksQueueSize (): number {
  83     return this.tasksQueue.size
  84   }
  85
  86   /** @inheritdoc */
  87   public enqueueTask (task: Task<Data>): number {
  88     const tasksQueueSize = this.tasksQueue.push(task)
  89     if (this.onBackPressure != null && this.hasBackPressure()) {
  90       once(this.onBackPressure, this)(this.info.id as number)
  91     }
  92     return tasksQueueSize
  93   }
  94
  95   /** @inheritdoc */
  96   public unshiftTask (task: Task<Data>): number {
  97     const tasksQueueSize = this.tasksQueue.unshift(task)
  98     if (this.onBackPressure != null && this.hasBackPressure()) {
  99       once(this.onBackPressure, this)(this.info.id as number)
 100     }
 101     return tasksQueueSize
 102   }
 103
 104   /** @inheritdoc */
 105   public dequeueTask (): Task<Data> | undefined {
 106     const task = this.tasksQueue.shift()
 107     if (this.onEmptyQueue != null && this.tasksQueue.size === 0) {
 108       once(this.onEmptyQueue, this)(this.info.id as number)
 109     }
 110     return task
 111   }
 112
 113   /** @inheritdoc */
 114   public popTask (): Task<Data> | undefined {
 115     const task = this.tasksQueue.pop()
 116     if (this.onEmptyQueue != null && this.tasksQueue.size === 0) {
 117       once(this.onEmptyQueue, this)(this.info.id as number)
 118     }
 119     return task
 120   }
 121
 122   /** @inheritdoc */
 123   public clearTasksQueue (): void {
 124     this.tasksQueue.clear()
 125   }
 126
 127   /** @inheritdoc */
 128   public hasBackPressure (): boolean {
 129     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 130   }
 131
 132   /** @inheritdoc */
 133   public resetUsage (): void {
 134     this.usage = this.initWorkerUsage()
 135     this.taskFunctionsUsage.clear()
 136   }
 137
 138   /** @inheritdoc */
 139   public closeChannel (): void {
 140     if (this.messageChannel != null) {
 141       this.messageChannel?.port1.unref()
 142       this.messageChannel?.port2.unref()
 143       this.messageChannel?.port1.close()
 144       this.messageChannel?.port2.close()
 145       delete this.messageChannel
 146     }
 147   }
 148
 149   /** @inheritdoc */
 150   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 151     if (!Array.isArray(this.info.taskFunctions)) {
 152       throw new Error(
 153         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 154       )
 155     }
 156     if (
 157       Array.isArray(this.info.taskFunctions) &&
 158       this.info.taskFunctions.length < 3
 159     ) {
 160       throw new Error(
 161         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 162       )
 163     }
 164     if (name === DEFAULT_TASK_NAME) {
 165       name = this.info.taskFunctions[1]
 166     }
 167     if (!this.taskFunctionsUsage.has(name)) {
 168       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 169     }
 170     return this.taskFunctionsUsage.get(name)
 171   }
 172
 173   private initWorkerInfo (worker: Worker, workerType: WorkerType): WorkerInfo {
 174     return {
 175       id: this.getWorkerId(worker, workerType),
 176       type: workerType,
 177       dynamic: false,
 178       ready: false
 179     }
 180   }
 181
 182   private initWorkerUsage (): WorkerUsage {
 183     const getTasksQueueSize = (): number => {
 184       return this.tasksQueue.size
 185     }
 186     const getTasksQueueMaxSize = (): number => {
 187       return this.tasksQueue.maxSize
 188     }
 189     return {
 190       tasks: {
 191         executed: 0,
 192         executing: 0,
 193         get queued (): number {
 194           return getTasksQueueSize()
 195         },
 196         get maxQueued (): number {
 197           return getTasksQueueMaxSize()
 198         },
 199         failed: 0
 200       },
 201       runTime: {
 202         history: new CircularArray()
 203       },
 204       waitTime: {
 205         history: new CircularArray()
 206       },
 207       elu: {
 208         idle: {
 209           history: new CircularArray()
 210         },
 211         active: {
 212           history: new CircularArray()
 213         }
 214       }
 215     }
 216   }
 217
 218   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 219     const getTaskFunctionQueueSize = (): number => {
 220       let taskFunctionQueueSize = 0
 221       for (const task of this.tasksQueue) {
 222         if (
 223           (task.name === DEFAULT_TASK_NAME &&
 224             name === (this.info.taskFunctions as string[])[1]) ||
 225           (task.name !== DEFAULT_TASK_NAME && name === task.name)
 226         ) {
 227           ++taskFunctionQueueSize
 228         }
 229       }
 230       return taskFunctionQueueSize
 231     }
 232     return {
 233       tasks: {
 234         executed: 0,
 235         executing: 0,
 236         get queued (): number {
 237           return getTaskFunctionQueueSize()
 238         },
 239         failed: 0
 240       },
 241       runTime: {
 242         history: new CircularArray()
 243       },
 244       waitTime: {
 245         history: new CircularArray()
 246       },
 247       elu: {
 248         idle: {
 249           history: new CircularArray()
 250         },
 251         active: {
 252           history: new CircularArray()
 253         }
 254       }
 255     }
 256   }
 257
 258   /**
 259    * Gets the worker id.
 260    *
 261    * @param worker - The worker.
 262    * @param workerType - The worker type.
 263    * @returns The worker id.
 264    */
 265   private getWorkerId (
 266     worker: Worker,
 267     workerType: WorkerType
 268   ): number | undefined {
 269     if (workerType === WorkerTypes.thread) {
 270       return worker.threadId
 271     } else if (workerType === WorkerTypes.cluster) {
 272       return worker.id
 273     }
 274   }
 275 }