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, getWorkerId, getWorkerType } from '../utils'
   5 import { Deque } from '../deque'
   6 import {
   7   type IWorker,
   8   type IWorkerNode,
   9   type StrategyData,
  10   type WorkerInfo,
  11   type WorkerNodeEventDetail,
  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 EventTarget
  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.dispatchEvent(
  75         new CustomEvent<WorkerNodeEventDetail>('backPressure', {
  76           detail: { workerId: this.info.id as number }
  77         })
  78       )
  79       this.onBackPressureStarted = false
  80     }
  81     return tasksQueueSize
  82   }
  83
  84   /** @inheritdoc */
  85   public unshiftTask (task: Task<Data>): number {
  86     const tasksQueueSize = this.tasksQueue.unshift(task)
  87     if (this.hasBackPressure() && !this.onBackPressureStarted) {
  88       this.onBackPressureStarted = true
  89       this.dispatchEvent(
  90         new CustomEvent<WorkerNodeEventDetail>('backPressure', {
  91           detail: { workerId: this.info.id as number }
  92         })
  93       )
  94       this.onBackPressureStarted = false
  95     }
  96     return tasksQueueSize
  97   }
  98
  99   /** @inheritdoc */
 100   public dequeueTask (): Task<Data> | undefined {
 101     return this.tasksQueue.shift()
 102   }
 103
 104   /** @inheritdoc */
 105   public popTask (): Task<Data> | undefined {
 106     return this.tasksQueue.pop()
 107   }
 108
 109   /** @inheritdoc */
 110   public clearTasksQueue (): void {
 111     this.tasksQueue.clear()
 112   }
 113
 114   /** @inheritdoc */
 115   public hasBackPressure (): boolean {
 116     return this.tasksQueue.size >= this.tasksQueueBackPressureSize
 117   }
 118
 119   /** @inheritdoc */
 120   public resetUsage (): void {
 121     this.usage = this.initWorkerUsage()
 122     this.taskFunctionsUsage.clear()
 123   }
 124
 125   /** @inheritdoc */
 126   public closeChannel (): void {
 127     if (this.messageChannel != null) {
 128       this.messageChannel.port1.unref()
 129       this.messageChannel.port2.unref()
 130       this.messageChannel.port1.close()
 131       this.messageChannel.port2.close()
 132       delete this.messageChannel
 133     }
 134   }
 135
 136   /** @inheritdoc */
 137   public getTaskFunctionWorkerUsage (name: string): WorkerUsage | undefined {
 138     if (!Array.isArray(this.info.taskFunctionNames)) {
 139       throw new Error(
 140         `Cannot get task function worker usage for task function name '${name}' when task function names list is not yet defined`
 141       )
 142     }
 143     if (
 144       Array.isArray(this.info.taskFunctionNames) &&
 145       this.info.taskFunctionNames.length < 3
 146     ) {
 147       throw new Error(
 148         `Cannot get task function worker usage for task function name '${name}' when task function names list has less than 3 elements`
 149       )
 150     }
 151     if (name === DEFAULT_TASK_NAME) {
 152       name = this.info.taskFunctionNames[1]
 153     }
 154     if (!this.taskFunctionsUsage.has(name)) {
 155       this.taskFunctionsUsage.set(name, this.initTaskFunctionWorkerUsage(name))
 156     }
 157     return this.taskFunctionsUsage.get(name)
 158   }
 159
 160   /** @inheritdoc */
 161   public deleteTaskFunctionWorkerUsage (name: string): boolean {
 162     return this.taskFunctionsUsage.delete(name)
 163   }
 164
 165   private initWorkerInfo (worker: Worker): WorkerInfo {
 166     return {
 167       id: getWorkerId(worker),
 168       type: getWorkerType(worker) as WorkerType,
 169       dynamic: false,
 170       ready: false
 171     }
 172   }
 173
 174   private initWorkerUsage (): WorkerUsage {
 175     const getTasksQueueSize = (): number => {
 176       return this.tasksQueue.size
 177     }
 178     const getTasksQueueMaxSize = (): number => {
 179       return this.tasksQueue.maxSize
 180     }
 181     return {
 182       tasks: {
 183         executed: 0,
 184         executing: 0,
 185         get queued (): number {
 186           return getTasksQueueSize()
 187         },
 188         get maxQueued (): number {
 189           return getTasksQueueMaxSize()
 190         },
 191         sequentiallyStolen: 0,
 192         stolen: 0,
 193         failed: 0
 194       },
 195       runTime: {
 196         history: new CircularArray<number>()
 197       },
 198       waitTime: {
 199         history: new CircularArray<number>()
 200       },
 201       elu: {
 202         idle: {
 203           history: new CircularArray<number>()
 204         },
 205         active: {
 206           history: new CircularArray<number>()
 207         }
 208       }
 209     }
 210   }
 211
 212   private initTaskFunctionWorkerUsage (name: string): WorkerUsage {
 213     const getTaskFunctionQueueSize = (): number => {
 214       let taskFunctionQueueSize = 0
 215       for (const task of this.tasksQueue) {
 216         if (
 217           (task.name === DEFAULT_TASK_NAME &&
 218             name === (this.info.taskFunctionNames as string[])[1]) ||
 219           (task.name !== DEFAULT_TASK_NAME && name === task.name)
 220         ) {
 221           ++taskFunctionQueueSize
 222         }
 223       }
 224       return taskFunctionQueueSize
 225     }
 226     return {
 227       tasks: {
 228         executed: 0,
 229         executing: 0,
 230         get queued (): number {
 231           return getTaskFunctionQueueSize()
 232         },
 233         sequentiallyStolen: 0,
 234         stolen: 0,
 235         failed: 0
 236       },
 237       runTime: {
 238         history: new CircularArray<number>()
 239       },
 240       waitTime: {
 241         history: new CircularArray<number>()
 242       },
 243       elu: {
 244         idle: {
 245           history: new CircularArray<number>()
 246         },
 247         active: {
 248           history: new CircularArray<number>()
 249         }
 250       }
 251     }
 252   }
 253 }