src/pools/worker-node.ts

   1 import { MessageChannel } from 'node:worker_threads'
   2 import { EventEmitter } from 'node:events'
   3 import { CircularArray } from '../circular-array'
   4 import type { Task } from '../utility-types'
   5 import { DEFAULT_TASK_NAME, getWorkerId, getWorkerType } from '../utils'
   6 import { Deque } from '../deque'
   7 import {
   8   type IWorker,
   9   type IWorkerNode,
  10   type StrategyData,
  11   type WorkerInfo,
  12   type WorkerType,
  13   WorkerTypes,
  14   type WorkerUsage
  15 } from './worker'
  16 import { checkWorkerNodeArguments } from './utils'
  17
  18 /**
  19  * Worker node.
  20  *
  21  * @typeParam Worker - Type of worker.
  22  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  23  */
  24 export class WorkerNode<Worker extends IWorker, Data = unknown>
  25   extends EventEmitter
  26   implements IWorkerNode<Worker, Data> {
  27   /** @inheritdoc */
  28   public readonly worker: Worker
  29   /** @inheritdoc */
  30   public readonly info: WorkerInfo
  31   /** @inheritdoc */
  32   public usage: WorkerUsage
  33   /** @inheritdoc */
  34   public strategyData?: StrategyData
  35   /** @inheritdoc */
  36   public messageChannel?: MessageChannel
  37   /** @inheritdoc */
  38   public tasksQueueBackPressureSize: number
  39   private readonly tasksQueue: Deque<Task<Data>>
  40   private onBackPressureStarted: boolean
  41   private readonly taskFunctionsUsage: Map<string, WorkerUsage>
  42
  43   /**
  44    * Constructs a new worker node.
  45    *
  46    * @param worker - The worker.
  47    * @param tasksQueueBackPressureSize - The tasks queue back pressure size.
  48    */
  49   constructor (worker: Worker, tasksQueueBackPressureSize: number) {
  50     super()
  51     checkWorkerNodeArguments<Worker>(worker, tasksQueueBackPressureSize)
  52     this.worker = worker
  53     this.info = this.initWorkerInfo(worker)
  54     this.usage = this.initWorkerUsage()
  55     if (this.info.type === WorkerTypes.thread) {
  56       this.messageChannel = new MessageChannel()
  57     }
  58     this.tasksQueueBackPressureSize = tasksQueueBackPressureSize
  59     this.tasksQueue = new Deque<Task<Data>>()
  60     this.onBackPressureStarted = false
  61     this.taskFunctionsUsage = new Map<string, WorkerUsage>()
  62   }
  63
  64   /** @inheritdoc */
  65   public tasksQueueSize (): number {
  66     return this.tasksQueue.size
  67   }
  68
  69   /** @inheritdoc */
  70   public enqueueTask (task: Task<Data>): number {
  71     const tasksQueueSize = this.tasksQueue.push(task)
  72     if (this.hasBackPressure() && !this.onBackPressureStarted) {
  73       this.onBackPressureStarted = true
  74       this.emit('backPressure', { workerId: this.info.id as number })
  75       this.onBackPressureStarted = false
  76     }
  77     return tasksQueueSize
  78   }
  79
  80   /** @inheritdoc */
  81   public unshiftTask (task: Task<Data>): number {
  82     const tasksQueueSize = this.tasksQueue.unshift(task)
  83     if (this.hasBackPressure() && !this.onBackPressureStarted) {
  84       this.onBackPressureStarted = true
  85       this.emit('backPressure', { workerId: this.info.id as number })
  86       this.onBackPressureStarted = false
  87     }
  88     return tasksQueueSize
  89   }
  90
  91   /** @inheritdoc */
  92   public dequeueTask (): Task<Data> | undefined {
  93     return this.tasksQueue.shift()
  94   }
  95
  96   /** @inheritdoc */
  97   public popTask (): Task<Data> | undefined {
  98     return this.tasksQueue.pop()
  99   }
 100
 101   /** @inheritdoc */
 102   public clearTasksQueue (): void {
 103     this.tasksQueue.clear()
 104   }
 105
 106   /** @inheritdoc */
 107   public hasBackPressure (): boolean {
 108     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 109   }
 110
 111   /** @inheritdoc */
 112   public resetUsage (): void {
 113     this.usage = this.initWorkerUsage()
 114     this.taskFunctionsUsage.clear()
 115   }
 116
 117   /** @inheritdoc */
 118   public closeChannel (): void {
 119     if (this.messageChannel != null) {
 120       this.messageChannel.port1.unref()
 121       this.messageChannel.port2.unref()
 122       this.messageChannel.port1.close()
 123       this.messageChannel.port2.close()
 124       delete this.messageChannel
 125     }
 126   }
 127
 128   /** @inheritdoc */
 129   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 130     if (!Array.isArray(this.info.taskFunctionNames)) {
 131       throw new Error(
 132         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 133       )
 134     }
 135     if (
 136       Array.isArray(this.info.taskFunctionNames) &&
 137       this.info.taskFunctionNames.length < 3
 138     ) {
 139       throw new Error(
 140         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 141       )
 142     }
 143     if (name === DEFAULT_TASK_NAME) {
 144       name = this.info.taskFunctionNames[1]
 145     }
 146     if (!this.taskFunctionsUsage.has(name)) {
 147       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 148     }
 149     return this.taskFunctionsUsage.get(name)
 150   }
 151
 152   /** @inheritdoc */
 153   public deleteTaskFunctionWorkerUsage (name: string): boolean {
 154     return this.taskFunctionsUsage.delete(name)
 155   }
 156
 157   private initWorkerInfo (worker: Worker): WorkerInfo {
 158     return {
 159       id: getWorkerId(worker),
 160       type: getWorkerType(worker) as WorkerType,
 161       dynamic: false,
 162       ready: false
 163     }
 164   }
 165
 166   private initWorkerUsage (): WorkerUsage {
 167     const getTasksQueueSize = (): number => {
 168       return this.tasksQueue.size
 169     }
 170     const getTasksQueueMaxSize = (): number => {
 171       return this.tasksQueue.maxSize
 172     }
 173     return {
 174       tasks: {
 175         executed: 0,
 176         executing: 0,
 177         get queued (): number {
 178           return getTasksQueueSize()
 179         },
 180         get maxQueued (): number {
 181           return getTasksQueueMaxSize()
 182         },
 183         sequentiallyStolen: 0,
 184         stolen: 0,
 185         failed: 0
 186       },
 187       runTime: {
 188         history: new CircularArray<number>()
 189       },
 190       waitTime: {
 191         history: new CircularArray<number>()
 192       },
 193       elu: {
 194         idle: {
 195           history: new CircularArray<number>()
 196         },
 197         active: {
 198           history: new CircularArray<number>()
 199         }
 200       }
 201     }
 202   }
 203
 204   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 205     const getTaskFunctionQueueSize = (): number => {
 206       let taskFunctionQueueSize = 0
 207       for (const task of this.tasksQueue) {
 208         if (
 209           (task.name === DEFAULT_TASK_NAME &&
 210             name === (this.info.taskFunctionNames as string[])[1]) ||
 211           (task.name !== DEFAULT_TASK_NAME && name === task.name)
 212         ) {
 213           ++taskFunctionQueueSize
 214         }
 215       }
 216       return taskFunctionQueueSize
 217     }
 218     return {
 219       tasks: {
 220         executed: 0,
 221         executing: 0,
 222         get queued (): number {
 223           return getTaskFunctionQueueSize()
 224         },
 225         sequentiallyStolen: 0,
 226         stolen: 0,
 227         failed: 0
 228       },
 229       runTime: {
 230         history: new CircularArray<number>()
 231       },
 232       waitTime: {
 233         history: new CircularArray<number>()
 234       },
 235       elu: {
 236         idle: {
 237           history: new CircularArray<number>()
 238         },
 239         active: {
 240           history: new CircularArray<number>()
 241         }
 242       }
 243     }
 244   }
 245 }