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 TypeError('Cannot construct a worker node without a worker')
  45     }
  46     if (workerType == null) {
  47       throw new TypeError(
  48         'Cannot construct a worker node without a worker type'
  49       )
  50     }
  51     if (poolMaxSize == null) {
  52       throw new TypeError(
  53         'Cannot construct a worker node without a pool maximum size'
  54       )
  55     }
  56     if (isNaN(poolMaxSize)) {
  57       throw new TypeError(
  58         'Cannot construct a worker node with a NaN pool maximum size'
  59       )
  60     }
  61     this.worker = worker
  62     this.info = this.initWorkerInfo(worker, workerType)
  63     if (workerType === WorkerTypes.thread) {
  64       this.messageChannel = new MessageChannel()
  65     }
  66     this.usage = this.initWorkerUsage()
  67     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  68     this.tasksQueue = new Queue<Task<Data>>()
  69     this.tasksQueueBackPressureSize = Math.pow(poolMaxSize, 2)
  70   }
  71
  72   /** @inheritdoc */
  73   public tasksQueueSize (): number {
  74     return this.tasksQueue.size
  75   }
  76
  77   /**
  78    * Tasks queue maximum size.
  79    *
  80    * @returns The tasks queue maximum size.
  81    */
  82   private tasksQueueMaxSize (): number {
  83     return this.tasksQueue.maxSize
  84   }
  85
  86   /** @inheritdoc */
  87   public enqueueTask (task: Task<Data>): number {
  88     return this.tasksQueue.enqueue(task)
  89   }
  90
  91   /** @inheritdoc */
  92   public dequeueTask (): Task<Data> | undefined {
  93     return this.tasksQueue.dequeue()
  94   }
  95
  96   /** @inheritdoc */
  97   public clearTasksQueue (): void {
  98     this.tasksQueue.clear()
  99   }
 100
 101   /** @inheritdoc */
 102   public hasBackPressure (): boolean {
 103     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 104   }
 105
 106   /** @inheritdoc */
 107   public resetUsage (): void {
 108     this.usage = this.initWorkerUsage()
 109     this.taskFunctionsUsage.clear()
 110   }
 111
 112   /** @inheritdoc */
 113   public closeChannel (): void {
 114     if (this.messageChannel != null) {
 115       this.messageChannel?.port1.unref()
 116       this.messageChannel?.port2.unref()
 117       this.messageChannel?.port1.close()
 118       this.messageChannel?.port2.close()
 119       delete this.messageChannel
 120     }
 121   }
 122
 123   /** @inheritdoc */
 124   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 125     if (!Array.isArray(this.info.taskFunctions)) {
 126       throw new Error(
 127         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 128       )
 129     }
 130     if (
 131       Array.isArray(this.info.taskFunctions) &&
 132       this.info.taskFunctions.length < 3
 133     ) {
 134       throw new Error(
 135         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 136       )
 137     }
 138     if (name === DEFAULT_TASK_NAME) {
 139       name = this.info.taskFunctions[1]
 140     }
 141     if (!this.taskFunctionsUsage.has(name)) {
 142       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 143     }
 144     return this.taskFunctionsUsage.get(name)
 145   }
 146
 147   private initWorkerInfo (worker: Worker, workerType: WorkerType): WorkerInfo {
 148     return {
 149       id: this.getWorkerId(worker, workerType),
 150       type: workerType,
 151       dynamic: false,
 152       ready: false
 153     }
 154   }
 155
 156   private initWorkerUsage (): WorkerUsage {
 157     const getTasksQueueSize = (): number => {
 158       return this.tasksQueueSize()
 159     }
 160     const getTasksQueueMaxSize = (): number => {
 161       return this.tasksQueueMaxSize()
 162     }
 163     return {
 164       tasks: {
 165         executed: 0,
 166         executing: 0,
 167         get queued (): number {
 168           return getTasksQueueSize()
 169         },
 170         get maxQueued (): number {
 171           return getTasksQueueMaxSize()
 172         },
 173         failed: 0
 174       },
 175       runTime: {
 176         history: new CircularArray()
 177       },
 178       waitTime: {
 179         history: new CircularArray()
 180       },
 181       elu: {
 182         idle: {
 183           history: new CircularArray()
 184         },
 185         active: {
 186           history: new CircularArray()
 187         }
 188       }
 189     }
 190   }
 191
 192   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 193     const getTaskQueueSize = (): number => {
 194       let taskQueueSize = 0
 195       for (const task of this.tasksQueue) {
 196         if (task.name === name) {
 197           ++taskQueueSize
 198         }
 199       }
 200       return taskQueueSize
 201     }
 202     return {
 203       tasks: {
 204         executed: 0,
 205         executing: 0,
 206         get queued (): number {
 207           return getTaskQueueSize()
 208         },
 209         failed: 0
 210       },
 211       runTime: {
 212         history: new CircularArray()
 213       },
 214       waitTime: {
 215         history: new CircularArray()
 216       },
 217       elu: {
 218         idle: {
 219           history: new CircularArray()
 220         },
 221         active: {
 222           history: new CircularArray()
 223         }
 224       }
 225     }
 226   }
 227
 228   /**
 229    * Gets the worker id.
 230    *
 231    * @param worker - The worker.
 232    * @param workerType - The worker type.
 233    * @returns The worker id.
 234    */
 235   private getWorkerId (
 236     worker: Worker,
 237     workerType: WorkerType
 238   ): number | undefined {
 239     if (workerType === WorkerTypes.thread) {
 240       return worker.threadId
 241     } else if (workerType === WorkerTypes.cluster) {
 242       return worker.id
 243     }
 244   }
 245 }