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 structured-cloneable data.
  16  * @typeParam Response - Type of execution response. This can only be structured-cloneable 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: {
  28       aggregate: true,
  29       average: false,
  30       median: false
  31     },
  32     waitTime: {
  33       aggregate: true,
  34       average: false,
  35       median: false
  36     },
  37     elu: {
  38       aggregate: false,
  39       average: false,
  40       median: false
  41     }
  42   }
  43
  44   /** @inheritDoc */
  45   public constructor (
  46     pool: IPool<Worker, Data, Response>,
  47     opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
  48   ) {
  49     super(pool, opts)
  50     this.setTaskStatisticsRequirements(this.opts)
  51   }
  52
  53   /** @inheritDoc */
  54   public reset (): boolean {
  55     return true
  56   }
  57
  58   /** @inheritDoc */
  59   public update (): boolean {
  60     return true
  61   }
  62
  63   /** @inheritDoc */
  64   public choose (): number {
  65     let minTime = Infinity
  66     for (const [workerNodeKey, workerNode] of this.pool.workerNodes.entries()) {
  67       const workerTime =
  68         workerNode.workerUsage.runTime.aggregate +
  69         workerNode.workerUsage.waitTime.aggregate
  70       if (workerTime === 0) {
  71         this.nextWorkerNodeId = workerNodeKey
  72         break
  73       } else if (workerTime < minTime) {
  74         minTime = workerTime
  75         this.nextWorkerNodeId = workerNodeKey
  76       }
  77     }
  78     return this.nextWorkerNodeId
  79   }
  80
  81   /** @inheritDoc */
  82   public remove (): boolean {
  83     return true
  84   }
  85 }