| 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 { LeastEluWorkerChoiceStrategy } from './least-elu-worker-choice-strategy' |
| 9 | import { RoundRobinWorkerChoiceStrategy } from './round-robin-worker-choice-strategy' |
| 10 | import type { |
| 11 | IWorkerChoiceStrategy, |
| 12 | StrategyPolicy, |
| 13 | TaskStatisticsRequirements, |
| 14 | WorkerChoiceStrategy, |
| 15 | WorkerChoiceStrategyOptions |
| 16 | } from './selection-strategies-types' |
| 17 | import { WorkerChoiceStrategies } from './selection-strategies-types' |
| 18 | import { WeightedRoundRobinWorkerChoiceStrategy } from './weighted-round-robin-worker-choice-strategy' |
| 19 | |
| 20 | /** |
| 21 | * The worker choice strategy context. |
| 22 | * |
| 23 | * @typeParam Worker - Type of worker. |
| 24 | * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data. |
| 25 | * @typeParam Response - Type of execution response. This can only be structured-cloneable data. |
| 26 | */ |
| 27 | export class WorkerChoiceStrategyContext< |
| 28 | Worker extends IWorker, |
| 29 | Data = unknown, |
| 30 | Response = unknown |
| 31 | > { |
| 32 | private readonly workerChoiceStrategies: Map< |
| 33 | WorkerChoiceStrategy, |
| 34 | IWorkerChoiceStrategy |
| 35 | > |
| 36 | |
| 37 | /** |
| 38 | * The number of times the worker choice strategy in the context has been retried. |
| 39 | */ |
| 40 | private retriesCount = 0 |
| 41 | |
| 42 | /** |
| 43 | * Worker choice strategy context constructor. |
| 44 | * |
| 45 | * @param pool - The pool instance. |
| 46 | * @param workerChoiceStrategy - The worker choice strategy. |
| 47 | * @param opts - The worker choice strategy options. |
| 48 | */ |
| 49 | public constructor ( |
| 50 | pool: IPool<Worker, Data, Response>, |
| 51 | private workerChoiceStrategy: WorkerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN, |
| 52 | private opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 53 | ) { |
| 54 | this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts } |
| 55 | this.execute = this.execute.bind(this) |
| 56 | this.workerChoiceStrategies = new Map< |
| 57 | WorkerChoiceStrategy, |
| 58 | IWorkerChoiceStrategy |
| 59 | >([ |
| 60 | [ |
| 61 | WorkerChoiceStrategies.ROUND_ROBIN, |
| 62 | new (RoundRobinWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 63 | pool, |
| 64 | opts |
| 65 | ) |
| 66 | ], |
| 67 | [ |
| 68 | WorkerChoiceStrategies.LEAST_USED, |
| 69 | new (LeastUsedWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 70 | pool, |
| 71 | opts |
| 72 | ) |
| 73 | ], |
| 74 | [ |
| 75 | WorkerChoiceStrategies.LEAST_BUSY, |
| 76 | new (LeastBusyWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 77 | pool, |
| 78 | opts |
| 79 | ) |
| 80 | ], |
| 81 | [ |
| 82 | WorkerChoiceStrategies.LEAST_ELU, |
| 83 | new (LeastEluWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 84 | pool, |
| 85 | opts |
| 86 | ) |
| 87 | ], |
| 88 | [ |
| 89 | WorkerChoiceStrategies.FAIR_SHARE, |
| 90 | new (FairShareWorkerChoiceStrategy.bind(this))<Worker, Data, Response>( |
| 91 | pool, |
| 92 | opts |
| 93 | ) |
| 94 | ], |
| 95 | [ |
| 96 | WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN, |
| 97 | new (WeightedRoundRobinWorkerChoiceStrategy.bind(this))< |
| 98 | Worker, |
| 99 | Data, |
| 100 | Response |
| 101 | >(pool, opts) |
| 102 | ], |
| 103 | [ |
| 104 | WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN, |
| 105 | new (InterleavedWeightedRoundRobinWorkerChoiceStrategy.bind(this))< |
| 106 | Worker, |
| 107 | Data, |
| 108 | Response |
| 109 | >(pool, opts) |
| 110 | ] |
| 111 | ]) |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Gets the strategy policy in the context. |
| 116 | * |
| 117 | * @returns The strategy policy. |
| 118 | */ |
| 119 | public getStrategyPolicy (): StrategyPolicy { |
| 120 | return ( |
| 121 | this.workerChoiceStrategies.get( |
| 122 | this.workerChoiceStrategy |
| 123 | ) as IWorkerChoiceStrategy |
| 124 | ).strategyPolicy |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * Gets the worker choice strategy in the context task statistics requirements. |
| 129 | * |
| 130 | * @returns The task statistics requirements. |
| 131 | */ |
| 132 | public getTaskStatisticsRequirements (): TaskStatisticsRequirements { |
| 133 | return ( |
| 134 | this.workerChoiceStrategies.get( |
| 135 | this.workerChoiceStrategy |
| 136 | ) as IWorkerChoiceStrategy |
| 137 | ).taskStatisticsRequirements |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Sets the worker choice strategy to use in the context. |
| 142 | * |
| 143 | * @param workerChoiceStrategy - The worker choice strategy to set. |
| 144 | */ |
| 145 | public setWorkerChoiceStrategy ( |
| 146 | workerChoiceStrategy: WorkerChoiceStrategy |
| 147 | ): void { |
| 148 | if (this.workerChoiceStrategy !== workerChoiceStrategy) { |
| 149 | this.workerChoiceStrategy = workerChoiceStrategy |
| 150 | } |
| 151 | this.workerChoiceStrategies.get(this.workerChoiceStrategy)?.reset() |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Updates the worker node key in the worker choice strategy in the context internals. |
| 156 | * |
| 157 | * @returns `true` if the update is successful, `false` otherwise. |
| 158 | */ |
| 159 | public update (workerNodeKey: number): boolean { |
| 160 | return ( |
| 161 | this.workerChoiceStrategies.get( |
| 162 | this.workerChoiceStrategy |
| 163 | ) as IWorkerChoiceStrategy |
| 164 | ).update(workerNodeKey) |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Executes the worker choice strategy in the context algorithm. |
| 169 | * |
| 170 | * @returns The key of the worker node. |
| 171 | * @throws {@link https://nodejs.org/api/errors.html#class-error} If after configured retries the worker node key is null or undefined . |
| 172 | */ |
| 173 | public execute (): number { |
| 174 | const workerNodeKey = ( |
| 175 | this.workerChoiceStrategies.get( |
| 176 | this.workerChoiceStrategy |
| 177 | ) as IWorkerChoiceStrategy |
| 178 | ).choose() |
| 179 | if ( |
| 180 | workerNodeKey == null && |
| 181 | this.retriesCount < (this.opts.retries as number) |
| 182 | ) { |
| 183 | this.retriesCount++ |
| 184 | return this.execute() |
| 185 | } else if (workerNodeKey == null) { |
| 186 | throw new Error( |
| 187 | `Worker node key chosen is null or undefined after ${this.retriesCount} retries` |
| 188 | ) |
| 189 | } |
| 190 | this.retriesCount = 0 |
| 191 | return workerNodeKey |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Removes the worker node key from the worker choice strategy in the context. |
| 196 | * |
| 197 | * @param workerNodeKey - The worker node key. |
| 198 | * @returns `true` if the removal is successful, `false` otherwise. |
| 199 | */ |
| 200 | public remove (workerNodeKey: number): boolean { |
| 201 | return ( |
| 202 | this.workerChoiceStrategies.get( |
| 203 | this.workerChoiceStrategy |
| 204 | ) as IWorkerChoiceStrategy |
| 205 | ).remove(workerNodeKey) |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Sets the worker choice strategies in the context options. |
| 210 | * |
| 211 | * @param opts - The worker choice strategy options. |
| 212 | */ |
| 213 | public setOptions (opts: WorkerChoiceStrategyOptions): void { |
| 214 | this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts } |
| 215 | for (const workerChoiceStrategy of this.workerChoiceStrategies.values()) { |
| 216 | workerChoiceStrategy.setOptions(opts) |
| 217 | } |
| 218 | } |
| 219 | } |