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   StrategyPolicy,
   7   TaskStatisticsRequirements,
   8   WorkerChoiceStrategyOptions,
   9 } from './selection-strategies-types.js'
  10 import {
  11   buildWorkerChoiceStrategyOptions,
  12   toggleMedianMeasurementStatisticsRequirements,
  13 } from './selection-strategies-utils.js'
  14
  15 /**
  16  * Worker choice strategy abstract base class.
  17  * @typeParam Worker - Type of worker which manages the strategy.
  18  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  19  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  20  */
  21 export abstract class AbstractWorkerChoiceStrategy<
  22   Worker extends IWorker,
  23   Data = unknown,
  24   Response = unknown
  25 > implements IWorkerChoiceStrategy {
  26   /**
  27    * The next worker node key.
  28    */
  29   protected nextWorkerNodeKey: number | undefined = 0
  30
  31   /**
  32    * The previous worker node key.
  33    */
  34   protected previousWorkerNodeKey = 0
  35
  36   /** @inheritDoc */
  37   public readonly strategyPolicy: StrategyPolicy = {
  38     dynamicWorkerUsage: false,
  39     dynamicWorkerReady: true,
  40   }
  41
  42   /** @inheritDoc */
  43   public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
  44     runTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  45     waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  46     elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  47   }
  48
  49   /**
  50    * Constructs a worker choice strategy bound to the pool.
  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     toggleMedianMeasurementStatisticsRequirements(
  66       this.taskStatisticsRequirements.runTime,
  67       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  68       opts!.runTime!.median
  69     )
  70     toggleMedianMeasurementStatisticsRequirements(
  71       this.taskStatisticsRequirements.waitTime,
  72       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  73       opts!.waitTime!.median
  74     )
  75     toggleMedianMeasurementStatisticsRequirements(
  76       this.taskStatisticsRequirements.elu,
  77       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  78       opts!.elu!.median
  79     )
  80   }
  81
  82   protected resetWorkerNodeKeyProperties (): void {
  83     this.nextWorkerNodeKey = 0
  84     this.previousWorkerNodeKey = 0
  85   }
  86
  87   /** @inheritDoc */
  88   public abstract reset (): boolean
  89
  90   /** @inheritDoc */
  91   public abstract update (workerNodeKey: number): boolean
  92
  93   /** @inheritDoc */
  94   public abstract choose (): number | undefined
  95
  96   /** @inheritDoc */
  97   public abstract remove (workerNodeKey: number): boolean
  98
  99   /** @inheritDoc */
 100   public setOptions (opts: WorkerChoiceStrategyOptions | undefined): void {
 101     this.opts = buildWorkerChoiceStrategyOptions<Worker, Data, Response>(
 102       this.pool,
 103       opts
 104     )
 105     this.setTaskStatisticsRequirements(this.opts)
 106   }
 107
 108   /**
 109    * Whether the worker node is ready or not.
 110    * @param workerNodeKey - The worker node key.
 111    * @returns Whether the worker node is ready or not.
 112    */
 113   protected isWorkerNodeReady (workerNodeKey: number): boolean {
 114     return this.pool.workerNodes[workerNodeKey]?.info?.ready ?? false
 115   }
 116
 117   /**
 118    * Check the next worker node key.
 119    */
 120   protected checkNextWorkerNodeKey (): void {
 121     if (
 122       this.nextWorkerNodeKey != null &&
 123       (this.nextWorkerNodeKey < 0 ||
 124         !this.isWorkerNodeReady(this.nextWorkerNodeKey))
 125     ) {
 126       delete this.nextWorkerNodeKey
 127     }
 128   }
 129
 130   /**
 131    * Gets the worker node task runtime.
 132    * If the task statistics require the average runtime, the average runtime is returned.
 133    * If the task statistics require the median runtime, the median runtime is returned.
 134    * @param workerNodeKey - The worker node key.
 135    * @returns The worker node task runtime.
 136    */
 137   protected getWorkerNodeTaskRunTime (workerNodeKey: number): number {
 138     return this.taskStatisticsRequirements.runTime.median
 139       ? this.pool.workerNodes[workerNodeKey].usage.runTime.median ?? 0
 140       : this.pool.workerNodes[workerNodeKey].usage.runTime.average ?? 0
 141   }
 142
 143   /**
 144    * Gets the worker node task wait time.
 145    * If the task statistics require the average wait time, the average wait time is returned.
 146    * If the task statistics require the median wait time, the median wait time is returned.
 147    * @param workerNodeKey - The worker node key.
 148    * @returns The worker node task wait time.
 149    */
 150   protected getWorkerNodeTaskWaitTime (workerNodeKey: number): number {
 151     return this.taskStatisticsRequirements.waitTime.median
 152       ? this.pool.workerNodes[workerNodeKey].usage.waitTime.median ?? 0
 153       : this.pool.workerNodes[workerNodeKey].usage.waitTime.average ?? 0
 154   }
 155
 156   /**
 157    * Gets the worker node task ELU.
 158    * If the task statistics require the average ELU, the average ELU is returned.
 159    * If the task statistics require the median ELU, the median ELU is returned.
 160    * @param workerNodeKey - The worker node key.
 161    * @returns The worker node task ELU.
 162    */
 163   protected getWorkerNodeTaskElu (workerNodeKey: number): number {
 164     return this.taskStatisticsRequirements.elu.median
 165       ? this.pool.workerNodes[workerNodeKey].usage.elu.active.median ?? 0
 166       : this.pool.workerNodes[workerNodeKey].usage.elu.active.average ?? 0
 167   }
 168
 169   /**
 170    * Sets safely the previous worker node key.
 171    * @param workerNodeKey - The worker node key.
 172    */
 173   protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void {
 174     this.previousWorkerNodeKey =
 175       workerNodeKey != null && workerNodeKey >= 0
 176         ? workerNodeKey
 177         : this.previousWorkerNodeKey
 178   }
 179 }