| 1 | import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils' |
| 2 | import type { IPool } from '../pool' |
| 3 | import type { IWorker } from '../worker' |
| 4 | import type { |
| 5 | IWorkerChoiceStrategy, |
| 6 | RequiredStatistics, |
| 7 | WorkerChoiceStrategyOptions |
| 8 | } from './selection-strategies-types' |
| 9 | |
| 10 | /** |
| 11 | * Worker choice strategy abstract base class. |
| 12 | * |
| 13 | * @typeParam Worker - Type of worker which manages the strategy. |
| 14 | * @typeParam Data - Type of data sent to the worker. This can only be serializable data. |
| 15 | * @typeParam Response - Type of execution response. This can only be serializable data. |
| 16 | */ |
| 17 | export abstract class AbstractWorkerChoiceStrategy< |
| 18 | Worker extends IWorker, |
| 19 | Data = unknown, |
| 20 | Response = unknown |
| 21 | > implements IWorkerChoiceStrategy { |
| 22 | /** |
| 23 | * Toggles finding the last free worker node key. |
| 24 | */ |
| 25 | private toggleFindLastFreeWorkerNodeKey: boolean = false |
| 26 | /** @inheritDoc */ |
| 27 | public readonly requiredStatistics: RequiredStatistics = { |
| 28 | runTime: false, |
| 29 | avgRunTime: false, |
| 30 | medRunTime: false |
| 31 | } |
| 32 | |
| 33 | /** |
| 34 | * Constructs a worker choice strategy bound to the pool. |
| 35 | * |
| 36 | * @param pool - The pool instance. |
| 37 | * @param opts - The worker choice strategy options. |
| 38 | */ |
| 39 | public constructor ( |
| 40 | protected readonly pool: IPool<Worker, Data, Response>, |
| 41 | protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 42 | ) { |
| 43 | this.choose = this.choose.bind(this) |
| 44 | } |
| 45 | |
| 46 | protected checkOptions (opts: WorkerChoiceStrategyOptions): void { |
| 47 | if (this.requiredStatistics.avgRunTime && opts.medRunTime === true) { |
| 48 | this.requiredStatistics.avgRunTime = false |
| 49 | this.requiredStatistics.medRunTime = opts.medRunTime as boolean |
| 50 | } |
| 51 | if (this.requiredStatistics.medRunTime && opts.medRunTime === false) { |
| 52 | this.requiredStatistics.avgRunTime = true |
| 53 | this.requiredStatistics.medRunTime = opts.medRunTime as boolean |
| 54 | } |
| 55 | if ( |
| 56 | opts.weights != null && |
| 57 | Object.keys(opts.weights).length < this.pool.size |
| 58 | ) { |
| 59 | throw new Error( |
| 60 | 'Worker choice strategy options must have a weight for each worker node.' |
| 61 | ) |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | /** @inheritDoc */ |
| 66 | public abstract reset (): boolean |
| 67 | |
| 68 | /** @inheritDoc */ |
| 69 | public abstract update (workerNodeKey: number): boolean |
| 70 | |
| 71 | /** @inheritDoc */ |
| 72 | public abstract choose (): number |
| 73 | |
| 74 | /** @inheritDoc */ |
| 75 | public abstract remove (workerNodeKey: number): boolean |
| 76 | |
| 77 | /** @inheritDoc */ |
| 78 | public setOptions (opts: WorkerChoiceStrategyOptions): void { |
| 79 | opts = opts ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 80 | this.checkOptions(opts) |
| 81 | this.opts = opts |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Finds a free worker node key. |
| 86 | * |
| 87 | * @returns The free worker node key or `-1` if there is no free worker node. |
| 88 | */ |
| 89 | protected findFreeWorkerNodeKey (): number { |
| 90 | if (this.toggleFindLastFreeWorkerNodeKey) { |
| 91 | this.toggleFindLastFreeWorkerNodeKey = false |
| 92 | return this.findLastFreeWorkerNodeKey() |
| 93 | } |
| 94 | this.toggleFindLastFreeWorkerNodeKey = true |
| 95 | return this.findFirstFreeWorkerNodeKey() |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Finds the first free worker node key based on the number of tasks the worker has applied. |
| 100 | * |
| 101 | * If a worker is found with `0` running tasks, it is detected as free and its worker node key is returned. |
| 102 | * |
| 103 | * If no free worker is found, `-1` is returned. |
| 104 | * |
| 105 | * @returns A worker node key if there is one, `-1` otherwise. |
| 106 | */ |
| 107 | private findFirstFreeWorkerNodeKey (): number { |
| 108 | return this.pool.workerNodes.findIndex(workerNode => { |
| 109 | return workerNode.tasksUsage.running === 0 |
| 110 | }) |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Finds the last free worker node key based on the number of tasks the worker has applied. |
| 115 | * |
| 116 | * If a worker is found with `0` running tasks, it is detected as free and its worker node key is returned. |
| 117 | * |
| 118 | * If no free worker is found, `-1` is returned. |
| 119 | * |
| 120 | * @returns A worker node key if there is one, `-1` otherwise. |
| 121 | */ |
| 122 | private findLastFreeWorkerNodeKey (): number { |
| 123 | // It requires node >= 18.0.0: |
| 124 | // return this.workerNodes.findLastIndex(workerNode => { |
| 125 | // return workerNode.tasksUsage.running === 0 |
| 126 | // }) |
| 127 | for (let i = this.pool.workerNodes.length - 1; i >= 0; i--) { |
| 128 | if (this.pool.workerNodes[i].tasksUsage.running === 0) { |
| 129 | return i |
| 130 | } |
| 131 | } |
| 132 | return -1 |
| 133 | } |
| 134 | } |