src/pools/selection-strategies/least-busy-worker-choice-strategy.ts

   1 import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
   2 import type { IPool } from '../pool'
   3 import type { IWorker } from '../worker'
   4 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
   5 import type {
   6   IWorkerChoiceStrategy,
   7   TaskStatisticsRequirements,
   8   WorkerChoiceStrategyOptions
   9 } from './selection-strategies-types'
  10
  11 /**
  12  * Selects the least busy worker.
  13  *
  14  * @typeParam Worker - Type of worker which manages the strategy.
  15  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  16  * @typeParam Response - Type of execution response. This can only be serializable data.
  17  */
  18 export class LeastBusyWorkerChoiceStrategy<
  19     Worker extends IWorker,
  20     Data = unknown,
  21     Response = unknown
  22   >
  23   extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
  24   implements IWorkerChoiceStrategy {
  25   /** @inheritDoc */
  26   public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
  27     runTime: true,
  28     avgRunTime: false,
  29     medRunTime: false,
  30     waitTime: true,
  31     avgWaitTime: false,
  32     medWaitTime: false,
  33     elu: false
  34   }
  35
  36   /** @inheritDoc */
  37   public constructor (
  38     pool: IPool<Worker, Data, Response>,
  39     opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
  40   ) {
  41     super(pool, opts)
  42     this.setTaskStatistics(this.opts)
  43   }
  44
  45   /** @inheritDoc */
  46   public reset (): boolean {
  47     return true
  48   }
  49
  50   /** @inheritDoc */
  51   public update (): boolean {
  52     return true
  53   }
  54
  55   /** @inheritDoc */
  56   public choose (): number {
  57     let minTime = Infinity
  58     let leastBusyWorkerNodeKey!: number
  59     for (const [workerNodeKey, workerNode] of this.pool.workerNodes.entries()) {
  60       const workerTime =
  61         workerNode.workerUsage.runTime.aggregation +
  62         workerNode.workerUsage.waitTime.aggregation
  63       if (workerTime === 0) {
  64         return workerNodeKey
  65       } else if (workerTime < minTime) {
  66         minTime = workerTime
  67         leastBusyWorkerNodeKey = workerNodeKey
  68       }
  69     }
  70     return leastBusyWorkerNodeKey
  71   }
  72
  73   /** @inheritDoc */
  74   public remove (): boolean {
  75     return true
  76   }
  77 }