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