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

   1 import {
   2   DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
   3   buildInternalWorkerChoiceStrategyOptions
   4 } from '../../utils.js'
   5 import type { IPool } from '../pool.js'
   6 import type { IWorker } from '../worker.js'
   7 import type {
   8   IWorkerChoiceStrategy,
   9   InternalWorkerChoiceStrategyOptions,
  10   MeasurementStatisticsRequirements,
  11   StrategyPolicy,
  12   TaskStatisticsRequirements
  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: InternalWorkerChoiceStrategyOptions
  59   ) {
  60     this.opts = buildInternalWorkerChoiceStrategyOptions(
  61       this.pool.info.maxSize,
  62       this.opts
  63     )
  64     this.setTaskStatisticsRequirements(this.opts)
  65     this.choose = this.choose.bind(this)
  66   }
  67
  68   protected setTaskStatisticsRequirements (
  69     opts: InternalWorkerChoiceStrategyOptions
  70   ): void {
  71     this.toggleMedianMeasurementStatisticsRequirements(
  72       this.taskStatisticsRequirements.runTime,
  73       opts.runTime?.median as boolean
  74     )
  75     this.toggleMedianMeasurementStatisticsRequirements(
  76       this.taskStatisticsRequirements.waitTime,
  77       opts.waitTime?.median as boolean
  78     )
  79     this.toggleMedianMeasurementStatisticsRequirements(
  80       this.taskStatisticsRequirements.elu,
  81       opts.elu?.median as boolean
  82     )
  83   }
  84
  85   private toggleMedianMeasurementStatisticsRequirements (
  86     measurementStatisticsRequirements: MeasurementStatisticsRequirements,
  87     toggleMedian: boolean
  88   ): void {
  89     if (measurementStatisticsRequirements.average && toggleMedian) {
  90       measurementStatisticsRequirements.average = false
  91       measurementStatisticsRequirements.median = toggleMedian
  92     }
  93     if (measurementStatisticsRequirements.median && !toggleMedian) {
  94       measurementStatisticsRequirements.average = true
  95       measurementStatisticsRequirements.median = toggleMedian
  96     }
  97   }
  98
  99   protected resetWorkerNodeKeyProperties (): void {
 100     this.nextWorkerNodeKey = 0
 101     this.previousWorkerNodeKey = 0
 102   }
 103
 104   /** @inheritDoc */
 105   public abstract reset (): boolean
 106
 107   /** @inheritDoc */
 108   public abstract update (workerNodeKey: number): boolean
 109
 110   /** @inheritDoc */
 111   public abstract choose (): number | undefined
 112
 113   /** @inheritDoc */
 114   public abstract remove (workerNodeKey: number): boolean
 115
 116   /** @inheritDoc */
 117   public setOptions (opts: InternalWorkerChoiceStrategyOptions): void {
 118     this.opts = buildInternalWorkerChoiceStrategyOptions(
 119       this.pool.info.maxSize,
 120       opts
 121     )
 122     this.setTaskStatisticsRequirements(this.opts)
 123   }
 124
 125   /** @inheritDoc */
 126   public hasPoolWorkerNodesReady (): boolean {
 127     return this.pool.workerNodes.some(workerNode => workerNode.info.ready)
 128   }
 129
 130   /**
 131    * Whether the worker node is ready or not.
 132    *
 133    * @param workerNodeKey - The worker node key.
 134    * @returns Whether the worker node is ready or not.
 135    */
 136   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 137     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 138   }
 139
 140   /**
 141    * Check the next worker node readiness.
 142    */
 143   protected checkNextWorkerNodeReadiness (): void {
 144     if (!this.isWorkerNodeReady(this.nextWorkerNodeKey as number)) {
 145       delete this.nextWorkerNodeKey
 146     }
 147   }
 148
 149   /**
 150    * Gets the worker node task runtime.
 151    * If the task statistics require the average runtime, the average runtime is returned.
 152    * If the task statistics require the median runtime , the median runtime is returned.
 153    *
 154    * @param workerNodeKey - The worker node key.
 155    * @returns The worker node task runtime.
 156    */
 157   protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
 158     return this.taskStatisticsRequirements.runTime.median
 159       ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
 160       : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
 161   }
 162
 163   /**
 164    * Gets the worker node task wait time.
 165    * If the task statistics require the average wait time, the average wait time is returned.
 166    * If the task statistics require the median wait time, the median wait time is returned.
 167    *
 168    * @param workerNodeKey - The worker node key.
 169    * @returns The worker node task wait time.
 170    */
 171   protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
 172     return this.taskStatisticsRequirements.waitTime.median
 173       ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
 174       : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
 175   }
 176
 177   /**
 178    * Gets the worker node task ELU.
 179    * If the task statistics require the average ELU, the average ELU is returned.
 180    * If the task statistics require the median ELU, the median ELU is returned.
 181    *
 182    * @param workerNodeKey - The worker node key.
 183    * @returns The worker node task ELU.
 184    */
 185   protected getWorkerNodeTaskElu (workerNodeKey: number): number {
 186     return this.taskStatisticsRequirements.elu.median
 187       ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
 188       : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
 189   }
 190
 191   /**
 192    * Sets safely the previous worker node key.
 193    *
 194    * @param workerNodeKey - The worker node key.
 195    */
 196   protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
 197     this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey
 198   }
 199 }