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

   1 import {
   2   DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
   3   buildWorkerChoiceStrategyOptions
   4 } from '../../utils.js'
   5 import type { IPool } from '../pool.js'
   6 import type { IWorker } from '../worker.js'
   7 import type {
   8   IWorkerChoiceStrategy,
   9   MeasurementStatisticsRequirements,
  10   StrategyPolicy,
  11   TaskStatisticsRequirements,
  12   WorkerChoiceStrategyOptions
  13 } from './selection-strategies-types.js'
  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?: WorkerChoiceStrategyOptions
  59   ) {
  60     this.opts = buildWorkerChoiceStrategyOptions<Worker, Data, Response>(
  61       this.pool,
  62       this.opts
  63     )
  64     this.setTaskStatisticsRequirements(this.opts)
  65     this.choose = this.choose.bind(this)
  66   }
  67
  68   protected setTaskStatisticsRequirements (
  69     opts: WorkerChoiceStrategyOptions | undefined
  70   ): void {
  71     this.toggleMedianMeasurementStatisticsRequirements(
  72       this.taskStatisticsRequirements.runTime,
  73       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  74       opts!.runTime!.median
  75     )
  76     this.toggleMedianMeasurementStatisticsRequirements(
  77       this.taskStatisticsRequirements.waitTime,
  78       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  79       opts!.waitTime!.median
  80     )
  81     this.toggleMedianMeasurementStatisticsRequirements(
  82       this.taskStatisticsRequirements.elu,
  83       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  84       opts!.elu!.median
  85     )
  86   }
  87
  88   private toggleMedianMeasurementStatisticsRequirements (
  89     measurementStatisticsRequirements: MeasurementStatisticsRequirements,
  90     toggleMedian: boolean
  91   ): void {
  92     if (measurementStatisticsRequirements.average && toggleMedian) {
  93       measurementStatisticsRequirements.average = false
  94       measurementStatisticsRequirements.median = toggleMedian
  95     }
  96     if (measurementStatisticsRequirements.median && !toggleMedian) {
  97       measurementStatisticsRequirements.average = true
  98       measurementStatisticsRequirements.median = toggleMedian
  99     }
 100   }
 101
 102   protected resetWorkerNodeKeyProperties (): void {
 103     this.nextWorkerNodeKey = 0
 104     this.previousWorkerNodeKey = 0
 105   }
 106
 107   /** @inheritDoc */
 108   public abstract reset (): boolean
 109
 110   /** @inheritDoc */
 111   public abstract update (workerNodeKey: number): boolean
 112
 113   /** @inheritDoc */
 114   public abstract choose (): number | undefined
 115
 116   /** @inheritDoc */
 117   public abstract remove (workerNodeKey: number): boolean
 118
 119   /** @inheritDoc */
 120   public setOptions (opts: WorkerChoiceStrategyOptions | undefined): void {
 121     this.opts = buildWorkerChoiceStrategyOptions<Worker, Data, Response>(
 122       this.pool,
 123       opts
 124     )
 125     this.setTaskStatisticsRequirements(this.opts)
 126   }
 127
 128   /** @inheritDoc */
 129   public hasPoolWorkerNodesReady (): boolean {
 130     return this.pool.workerNodes.some(workerNode => workerNode.info.ready)
 131   }
 132
 133   /**
 134    * Whether the worker node is ready or not.
 135    *
 136    * @param workerNodeKey - The worker node key.
 137    * @returns Whether the worker node is ready or not.
 138    */
 139   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 140     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 141   }
 142
 143   /**
 144    * Check the next worker node readiness.
 145    */
 146   protected checkNextWorkerNodeReadiness (): void {
 147     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
 148     if (!this.isWorkerNodeReady(this.nextWorkerNodeKey!)) {
 149       delete this.nextWorkerNodeKey
 150     }
 151   }
 152
 153   /**
 154    * Gets the worker node task runtime.
 155    * If the task statistics require the average runtime, the average runtime is returned.
 156    * If the task statistics require the median runtime , the median runtime is returned.
 157    *
 158    * @param workerNodeKey - The worker node key.
 159    * @returns The worker node task runtime.
 160    */
 161   protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
 162     return this.taskStatisticsRequirements.runTime.median
 163       ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
 164       : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
 165   }
 166
 167   /**
 168    * Gets the worker node task wait time.
 169    * If the task statistics require the average wait time, the average wait time is returned.
 170    * If the task statistics require the median wait time, the median wait time is returned.
 171    *
 172    * @param workerNodeKey - The worker node key.
 173    * @returns The worker node task wait time.
 174    */
 175   protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
 176     return this.taskStatisticsRequirements.waitTime.median
 177       ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
 178       : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
 179   }
 180
 181   /**
 182    * Gets the worker node task ELU.
 183    * If the task statistics require the average ELU, the average ELU is returned.
 184    * If the task statistics require the median ELU, the median ELU is returned.
 185    *
 186    * @param workerNodeKey - The worker node key.
 187    * @returns The worker node task ELU.
 188    */
 189   protected getWorkerNodeTaskElu (workerNodeKey: number): number {
 190     return this.taskStatisticsRequirements.elu.median
 191       ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
 192       : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
 193   }
 194
 195   /**
 196    * Sets safely the previous worker node key.
 197    *
 198    * @param workerNodeKey - The worker node key.
 199    */
 200   protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
 201     this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey
 202   }
 203 }