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

   1 import type { IPool } from '../pool.js'
   2 import { DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS } from '../utils.js'
   3 import type { IWorker } from '../worker.js'
   4 import type {
   5   IWorkerChoiceStrategy,
   6   MeasurementStatisticsRequirements,
   7   StrategyPolicy,
   8   TaskStatisticsRequirements,
   9   WorkerChoiceStrategyOptions
  10 } from './selection-strategies-types.js'
  11 import { buildWorkerChoiceStrategyOptions } from './selection-strategies-utils.js'
  12
  13 /**
  14  * Worker choice strategy abstract base class.
  15  *
  16  * @typeParam Worker - Type of worker which manages the strategy.
  17  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  18  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  19  */
  20 export abstract class AbstractWorkerChoiceStrategy<
  21   Worker extends IWorker,
  22   Data = unknown,
  23   Response = unknown
  24 > implements IWorkerChoiceStrategy {
  25   /**
  26    * The next worker node key.
  27    */
  28   protected nextWorkerNodeKey: number | undefined = 0
  29
  30   /**
  31    * The previous worker node key.
  32    */
  33   protected previousWorkerNodeKey = 0
  34
  35   /** @inheritDoc */
  36   public readonly strategyPolicy: StrategyPolicy = {
  37     dynamicWorkerUsage: false,
  38     dynamicWorkerReady: true
  39   }
  40
  41   /** @inheritDoc */
  42   public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
  43     runTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  44     waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  45     elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS
  46   }
  47
  48   /**
  49    * Constructs a worker choice strategy bound to the pool.
  50    *
  51    * @param pool - The pool instance.
  52    * @param opts - The worker choice strategy options.
  53    */
  54   public constructor (
  55     protected readonly pool: IPool<Worker, Data, Response>,
  56     protected opts?: WorkerChoiceStrategyOptions
  57   ) {
  58     this.choose = this.choose.bind(this)
  59     this.setOptions(this.opts)
  60   }
  61
  62   protected setTaskStatisticsRequirements (
  63     opts: WorkerChoiceStrategyOptions | undefined
  64   ): void {
  65     this.toggleMedianMeasurementStatisticsRequirements(
  66       this.taskStatisticsRequirements.runTime,
  67       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  68       opts!.runTime!.median
  69     )
  70     this.toggleMedianMeasurementStatisticsRequirements(
  71       this.taskStatisticsRequirements.waitTime,
  72       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  73       opts!.waitTime!.median
  74     )
  75     this.toggleMedianMeasurementStatisticsRequirements(
  76       this.taskStatisticsRequirements.elu,
  77       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  78       opts!.elu!.median
  79     )
  80   }
  81
  82   private toggleMedianMeasurementStatisticsRequirements (
  83     measurementStatisticsRequirements: MeasurementStatisticsRequirements,
  84     toggleMedian: boolean
  85   ): void {
  86     if (measurementStatisticsRequirements.average && toggleMedian) {
  87       measurementStatisticsRequirements.average = false
  88       measurementStatisticsRequirements.median = toggleMedian
  89     }
  90     if (measurementStatisticsRequirements.median && !toggleMedian) {
  91       measurementStatisticsRequirements.average = true
  92       measurementStatisticsRequirements.median = toggleMedian
  93     }
  94   }
  95
  96   protected resetWorkerNodeKeyProperties (): void {
  97     this.nextWorkerNodeKey = 0
  98     this.previousWorkerNodeKey = 0
  99   }
 100
 101   /** @inheritDoc */
 102   public abstract reset (): boolean
 103
 104   /** @inheritDoc */
 105   public abstract update (workerNodeKey: number): boolean
 106
 107   /** @inheritDoc */
 108   public abstract choose (): number | undefined
 109
 110   /** @inheritDoc */
 111   public abstract remove (workerNodeKey: number): boolean
 112
 113   /** @inheritDoc */
 114   public setOptions (opts: WorkerChoiceStrategyOptions | undefined): void {
 115     this.opts = buildWorkerChoiceStrategyOptions<Worker, Data, Response>(
 116       this.pool,
 117       opts
 118     )
 119     this.setTaskStatisticsRequirements(this.opts)
 120   }
 121
 122   /**
 123    * Whether the worker node is ready or not.
 124    *
 125    * @param workerNodeKey - The worker node key.
 126    * @returns Whether the worker node is ready or not.
 127    */
 128   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 129     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 130   }
 131
 132   /**
 133    * Check the next worker node key.
 134    */
 135   protected checkNextWorkerNodeKey (): void {
 136     if (
 137       this.nextWorkerNodeKey != null &&
 138       (this.nextWorkerNodeKey < 0 ||
 139         !this.isWorkerNodeReady(this.nextWorkerNodeKey))
 140     ) {
 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 =
 194       workerNodeKey != null && workerNodeKey >= 0
 195         ? workerNodeKey
 196         : this.previousWorkerNodeKey
 197   }
 198 }