| 1 | import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils' |
| 2 | import type { IPool } from '../pool' |
| 3 | import type { IWorker } from '../worker' |
| 4 | import { FairShareWorkerChoiceStrategy } from './fair-share-worker-choice-strategy' |
| 5 | import { InterleavedWeightedRoundRobinWorkerChoiceStrategy } from './interleaved-weighted-round-robin-worker-choice-strategy' |
| 6 | import { LeastBusyWorkerChoiceStrategy } from './least-busy-worker-choice-strategy' |
| 7 | import { LeastUsedWorkerChoiceStrategy } from './least-used-worker-choice-strategy' |
| 8 | import { RoundRobinWorkerChoiceStrategy } from './round-robin-worker-choice-strategy' |
| 9 | import type { |
| 10 | IWorkerChoiceStrategy, |
| 11 | RequiredStatistics, |
| 12 | WorkerChoiceStrategy, |
| 13 | WorkerChoiceStrategyOptions |
| 14 | } from './selection-strategies-types' |
| 15 | import { WorkerChoiceStrategies } from './selection-strategies-types' |
| 16 | import { WeightedRoundRobinWorkerChoiceStrategy } from './weighted-round-robin-worker-choice-strategy' |
| 17 | |
| 18 | /** |
| 19 | * The worker choice strategy context. |
| 20 | * |
| 21 | * @typeParam Worker - Type of worker. |
| 22 | * @typeParam Data - Type of data sent to the worker. This can only be serializable data. |
| 23 | * @typeParam Response - Type of execution response. This can only be serializable data. |
| 24 | */ |
| 25 | export class WorkerChoiceStrategyContext< |
| 26 | Worker extends IWorker, |
| 27 | Data = unknown, |
| 28 | Response = unknown |
| 29 | > { |
| 30 | private readonly workerChoiceStrategies: Map< |
| 31 | WorkerChoiceStrategy, |
| 32 | IWorkerChoiceStrategy |
| 33 | > |
| 34 | |
| 35 | /** |
| 36 | * Worker choice strategy context constructor. |
| 37 | * |
| 38 | * @param pool - The pool instance. |
| 39 | * @param workerChoiceStrategy - The worker choice strategy. |
| 40 | * @param opts - The worker choice strategy options. |
| 41 | */ |
| 42 | public constructor ( |
| 43 | pool: IPool<Worker, Data, Response>, |
| 44 | private workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN, |
| 45 | opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 46 | ) { |
| 47 | this.execute = this.execute.bind(this) |
| 48 | this.workerChoiceStrategies = new Map< |
| 49 | WorkerChoiceStrategy, |
| 50 | IWorkerChoiceStrategy |
| 51 | >([ |
| 52 | [ |
| 53 | WorkerChoiceStrategies.ROUND_ROBIN, |
| 54 | new (RoundRobinWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 55 | pool, |
| 56 | opts |
| 57 | ) |
| 58 | ], |
| 59 | [ |
| 60 | WorkerChoiceStrategies.LEAST_USED, |
| 61 | new (LeastUsedWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 62 | pool, |
| 63 | opts |
| 64 | ) |
| 65 | ], |
| 66 | [ |
| 67 | WorkerChoiceStrategies.LEAST_BUSY, |
| 68 | new (LeastBusyWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 69 | pool, |
| 70 | opts |
| 71 | ) |
| 72 | ], |
| 73 | [ |
| 74 | WorkerChoiceStrategies.FAIR_SHARE, |
| 75 | new (FairShareWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 76 | pool, |
| 77 | opts |
| 78 | ) |
| 79 | ], |
| 80 | [ |
| 81 | WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN, |
| 82 | new (WeightedRoundRobinWorkerChoiceStrategy.bind(this))< |
| 83 | Worker, |
| 84 | Data, |
| 85 | Response |
| 86 | >(pool, opts) |
| 87 | ], |
| 88 | [ |
| 89 | WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN, |
| 90 | new (InterleavedWeightedRoundRobinWorkerChoiceStrategy.bind(this))< |
| 91 | Worker, |
| 92 | Data, |
| 93 | Response |
| 94 | >(pool, opts) |
| 95 | ] |
| 96 | ]) |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Gets the worker choice strategy in the context required statistics. |
| 101 | * |
| 102 | * @returns The required statistics. |
| 103 | */ |
| 104 | public getRequiredStatistics (): RequiredStatistics { |
| 105 | return ( |
| 106 | this.workerChoiceStrategies.get( |
| 107 | this.workerChoiceStrategy |
| 108 | ) as IWorkerChoiceStrategy |
| 109 | ).requiredStatistics |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Sets the worker choice strategy to use in the context. |
| 114 | * |
| 115 | * @param workerChoiceStrategy - The worker choice strategy to set. |
| 116 | */ |
| 117 | public setWorkerChoiceStrategy ( |
| 118 | workerChoiceStrategy: WorkerChoiceStrategy |
| 119 | ): void { |
| 120 | if (this.workerChoiceStrategy !== workerChoiceStrategy) { |
| 121 | this.workerChoiceStrategy = workerChoiceStrategy |
| 122 | } |
| 123 | this.workerChoiceStrategies.get(this.workerChoiceStrategy)?.reset() |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Updates the worker node key in the worker choice strategy internals in the context. |
| 128 | * |
| 129 | * @returns `true` if the update is successful, `false` otherwise. |
| 130 | */ |
| 131 | public update (workerNodeKey: number): boolean { |
| 132 | return ( |
| 133 | this.workerChoiceStrategies.get( |
| 134 | this.workerChoiceStrategy |
| 135 | ) as IWorkerChoiceStrategy |
| 136 | ).update(workerNodeKey) |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Executes the worker choice strategy algorithm in the context. |
| 141 | * |
| 142 | * @returns The key of the worker node. |
| 143 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker node key is null or undefined. |
| 144 | */ |
| 145 | public execute (): number { |
| 146 | const workerNodeKey = ( |
| 147 | this.workerChoiceStrategies.get( |
| 148 | this.workerChoiceStrategy |
| 149 | ) as IWorkerChoiceStrategy |
| 150 | ).choose() |
| 151 | if (workerNodeKey == null) { |
| 152 | throw new Error('Worker node key chosen is null or undefined') |
| 153 | } |
| 154 | return workerNodeKey |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * Removes the worker node key from the worker choice strategy in the context. |
| 159 | * |
| 160 | * @param workerNodeKey - The key of the worker node. |
| 161 | * @returns `true` if the removal is successful, `false` otherwise. |
| 162 | */ |
| 163 | public remove (workerNodeKey: number): boolean { |
| 164 | return ( |
| 165 | this.workerChoiceStrategies.get( |
| 166 | this.workerChoiceStrategy |
| 167 | ) as IWorkerChoiceStrategy |
| 168 | ).remove(workerNodeKey) |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Sets the worker choice strategies in the context options. |
| 173 | * |
| 174 | * @param opts - The worker choice strategy options. |
| 175 | */ |
| 176 | public setOptions (opts: WorkerChoiceStrategyOptions): void { |
| 177 | for (const workerChoiceStrategy of this.workerChoiceStrategies.values()) { |
| 178 | workerChoiceStrategy.setOptions(opts) |
| 179 | } |
| 180 | } |
| 181 | } |