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.opts = buildInternalWorkerChoiceStrategyOptions(
  62       this.pool.info.maxSize,
  63       this.opts
  64     )
  65     this.setTaskStatisticsRequirements(this.opts)
  66     this.choose = this.choose.bind(this)
  67   }
  68
  69   protected setTaskStatisticsRequirements (
  70     opts: InternalWorkerChoiceStrategyOptions
  71   ): void {
  72     this.toggleMedianMeasurementStatisticsRequirements(
  73       this.taskStatisticsRequirements.runTime,
  74       opts.runTime?.median as boolean
  75     )
  76     this.toggleMedianMeasurementStatisticsRequirements(
  77       this.taskStatisticsRequirements.waitTime,
  78       opts.waitTime?.median as boolean
  79     )
  80     this.toggleMedianMeasurementStatisticsRequirements(
  81       this.taskStatisticsRequirements.elu,
  82       opts.elu?.median as boolean
  83     )
  84   }
  85
  86   private toggleMedianMeasurementStatisticsRequirements (
  87     measurementStatisticsRequirements: MeasurementStatisticsRequirements,
  88     toggleMedian: boolean
  89   ): void {
  90     if (measurementStatisticsRequirements.average && toggleMedian) {
  91       measurementStatisticsRequirements.average = false
  92       measurementStatisticsRequirements.median = toggleMedian
  93     }
  94     if (measurementStatisticsRequirements.median && !toggleMedian) {
  95       measurementStatisticsRequirements.average = true
  96       measurementStatisticsRequirements.median = toggleMedian
  97     }
  98   }
  99
 100   protected resetWorkerNodeKeyProperties (): void {
 101     this.nextWorkerNodeKey = 0
 102     this.previousWorkerNodeKey = 0
 103   }
 104
 105   /** @inheritDoc */
 106   public abstract reset (): boolean
 107
 108   /** @inheritDoc */
 109   public abstract update (workerNodeKey: number): boolean
 110
 111   /** @inheritDoc */
 112   public abstract choose (): number | undefined
 113
 114   /** @inheritDoc */
 115   public abstract remove (workerNodeKey: number): boolean
 116
 117   /** @inheritDoc */
 118   public setOptions (opts: InternalWorkerChoiceStrategyOptions): void {
 119     this.opts = buildInternalWorkerChoiceStrategyOptions(
 120       this.pool.info.maxSize,
 121       opts
 122     )
 123     this.setTaskStatisticsRequirements(this.opts)
 124   }
 125
 126   /** @inheritDoc */
 127   public hasPoolWorkerNodesReady (): boolean {
 128     return this.pool.workerNodes.some(workerNode => workerNode.info.ready)
 129   }
 130
 131   /**
 132    * Whether the worker node is ready or not.
 133    *
 134    * @param workerNodeKey - The worker node key.
 135    * @returns Whether the worker node is ready or not.
 136    */
 137   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 138     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 139   }
 140
 141   /**
 142    * Check the next worker node readiness.
 143    */
 144   protected checkNextWorkerNodeReadiness (): void {
 145     if (!this.isWorkerNodeReady(this.nextWorkerNodeKey as number)) {
 146       delete this.nextWorkerNodeKey
 147     }
 148   }
 149
 150   /**
 151    * Gets the worker node task runtime.
 152    * If the task statistics require the average runtime, the average runtime is returned.
 153    * If the task statistics require the median runtime , the median runtime is returned.
 154    *
 155    * @param workerNodeKey - The worker node key.
 156    * @returns The worker node task runtime.
 157    */
 158   protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
 159     return this.taskStatisticsRequirements.runTime.median
 160       ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
 161       : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
 162   }
 163
 164   /**
 165    * Gets the worker node task wait time.
 166    * If the task statistics require the average wait time, the average wait time is returned.
 167    * If the task statistics require the median wait time, the median wait time is returned.
 168    *
 169    * @param workerNodeKey - The worker node key.
 170    * @returns The worker node task wait time.
 171    */
 172   protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
 173     return this.taskStatisticsRequirements.waitTime.median
 174       ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
 175       : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
 176   }
 177
 178   /**
 179    * Gets the worker node task ELU.
 180    * If the task statistics require the average ELU, the average ELU is returned.
 181    * If the task statistics require the median ELU, the median ELU is returned.
 182    *
 183    * @param workerNodeKey - The worker node key.
 184    * @returns The worker node task ELU.
 185    */
 186   protected getWorkerNodeTaskElu (workerNodeKey: number): number {
 187     return this.taskStatisticsRequirements.elu.median
 188       ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
 189       : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
 190   }
 191
 192   /**
 193    * Sets safely the previous worker node key.
 194    *
 195    * @param workerNodeKey - The worker node key.
 196    */
 197   protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
 198     this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey
 199   }
 200 }