src/pools/selection-strategies/abstract-worker-choice-strategy.ts

   1 import {
   2   DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
   3   buildInternalWorkerChoiceStrategyOptions
   4 } from '../../utils'
   5 import type { IPool } from '../pool'
   6 import type { IWorker } from '../worker'
   7 import type {
   8   IWorkerChoiceStrategy,
   9   InternalWorkerChoiceStrategyOptions,
  10   MeasurementStatisticsRequirements,
  11   StrategyPolicy,
  12   TaskStatisticsRequirements
  13 } from './selection-strategies-types'
  14
  15 /**
  16  * Worker choice strategy abstract base class.
  17  *
  18  * @typeParam Worker - Type of worker which manages the strategy.
  19  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  20  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  21  */
  22 export abstract class AbstractWorkerChoiceStrategy<
  23   Worker extends IWorker,
  24   Data = unknown,
  25   Response = unknown
  26 > implements IWorkerChoiceStrategy {
  27   /**
  28    * The next worker node key.
  29    */
  30   protected nextWorkerNodeKey: number | undefined = 0
  31
  32   /**
  33    * The previous worker node key.
  34    */
  35   protected previousWorkerNodeKey: number = 0
  36
  37   /** @inheritDoc */
  38   public readonly strategyPolicy: StrategyPolicy = {
  39     dynamicWorkerUsage: false,
  40     dynamicWorkerReady: true
  41   }
  42
  43   /** @inheritDoc */
  44   public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
  45     runTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  46     waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  47     elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS
  48   }
  49
  50   /**
  51    * Constructs a worker choice strategy bound to the pool.
  52    *
  53    * @param pool - The pool instance.
  54    * @param opts - The worker choice strategy options.
  55    */
  56   public constructor (
  57     protected readonly pool: IPool<Worker, Data, Response>,
  58     protected opts: InternalWorkerChoiceStrategyOptions
  59   ) {
  60     this.setOptions(this.opts)
  61     this.choose = this.choose.bind(this)
  62   }
  63
  64   protected setTaskStatisticsRequirements (
  65     opts: InternalWorkerChoiceStrategyOptions
  66   ): void {
  67     this.toggleMedianMeasurementStatisticsRequirements(
  68       this.taskStatisticsRequirements.runTime,
  69       opts.runTime?.median as boolean
  70     )
  71     this.toggleMedianMeasurementStatisticsRequirements(
  72       this.taskStatisticsRequirements.waitTime,
  73       opts.waitTime?.median as boolean
  74     )
  75     this.toggleMedianMeasurementStatisticsRequirements(
  76       this.taskStatisticsRequirements.elu,
  77       opts.elu?.median as boolean
  78     )
  79   }
  80
  81   private toggleMedianMeasurementStatisticsRequirements (
  82     measurementStatisticsRequirements: MeasurementStatisticsRequirements,
  83     toggleMedian: boolean
  84   ): void {
  85     if (measurementStatisticsRequirements.average && toggleMedian) {
  86       measurementStatisticsRequirements.average = false
  87       measurementStatisticsRequirements.median = toggleMedian
  88     }
  89     if (measurementStatisticsRequirements.median && !toggleMedian) {
  90       measurementStatisticsRequirements.average = true
  91       measurementStatisticsRequirements.median = toggleMedian
  92     }
  93   }
  94
  95   protected resetWorkerNodeKeyProperties (): void {
  96     this.nextWorkerNodeKey = 0
  97     this.previousWorkerNodeKey = 0
  98   }
  99
 100   /** @inheritDoc */
 101   public abstract reset (): boolean
 102
 103   /** @inheritDoc */
 104   public abstract update (workerNodeKey: number): boolean
 105
 106   /** @inheritDoc */
 107   public abstract choose (): number | undefined
 108
 109   /** @inheritDoc */
 110   public abstract remove (workerNodeKey: number): boolean
 111
 112   /** @inheritDoc */
 113   public setOptions (opts: InternalWorkerChoiceStrategyOptions): void {
 114     this.opts = buildInternalWorkerChoiceStrategyOptions(
 115       this.pool.info.maxSize,
 116       opts
 117     )
 118     this.setTaskStatisticsRequirements(this.opts)
 119   }
 120
 121   /** @inheritDoc */
 122   public hasPoolWorkerNodesReady (): boolean {
 123     return this.pool.workerNodes.some(workerNode => workerNode.info.ready)
 124   }
 125
 126   /**
 127    * Whether the worker node is ready or not.
 128    *
 129    * @param workerNodeKey - The worker node key.
 130    * @returns Whether the worker node is ready or not.
 131    */
 132   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 133     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 134   }
 135
 136   /**
 137    * Check the next worker node readiness.
 138    */
 139   protected checkNextWorkerNodeReadiness (): void {
 140     if (!this.isWorkerNodeReady(this.nextWorkerNodeKey as number)) {
 141       delete this.nextWorkerNodeKey
 142     }
 143   }
 144
 145   /**
 146    * Gets the worker node task runtime.
 147    * If the task statistics require the average runtime, the average runtime is returned.
 148    * If the task statistics require the median runtime , the median runtime is returned.
 149    *
 150    * @param workerNodeKey - The worker node key.
 151    * @returns The worker node task runtime.
 152    */
 153   protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
 154     return this.taskStatisticsRequirements.runTime.median
 155       ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
 156       : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
 157   }
 158
 159   /**
 160    * Gets the worker node task wait time.
 161    * If the task statistics require the average wait time, the average wait time is returned.
 162    * If the task statistics require the median wait time, the median wait time is returned.
 163    *
 164    * @param workerNodeKey - The worker node key.
 165    * @returns The worker node task wait time.
 166    */
 167   protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
 168     return this.taskStatisticsRequirements.waitTime.median
 169       ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
 170       : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
 171   }
 172
 173   /**
 174    * Gets the worker node task ELU.
 175    * If the task statistics require the average ELU, the average ELU is returned.
 176    * If the task statistics require the median ELU, the median ELU is returned.
 177    *
 178    * @param workerNodeKey - The worker node key.
 179    * @returns The worker node task ELU.
 180    */
 181   protected getWorkerNodeTaskElu (workerNodeKey: number): number {
 182     return this.taskStatisticsRequirements.elu.median
 183       ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
 184       : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
 185   }
 186
 187   /**
 188    * Sets safely the previous worker node key.
 189    *
 190    * @param workerNodeKey - The worker node key.
 191    */
 192   protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
 193     this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey
 194   }
 195 }