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