| 1 | import { cpus } from 'node:os' |
| 2 | import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils' |
| 3 | import type { IPool } from '../pool' |
| 4 | import type { IWorker } from '../worker' |
| 5 | import type { |
| 6 | IWorkerChoiceStrategy, |
| 7 | TaskStatisticsRequirements, |
| 8 | WorkerChoiceStrategyOptions |
| 9 | } from './selection-strategies-types' |
| 10 | |
| 11 | /** |
| 12 | * Worker choice strategy abstract base class. |
| 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 abstract class AbstractWorkerChoiceStrategy< |
| 19 | Worker extends IWorker, |
| 20 | Data = unknown, |
| 21 | Response = unknown |
| 22 | > implements IWorkerChoiceStrategy { |
| 23 | /** |
| 24 | * Toggles finding the last free worker node key. |
| 25 | */ |
| 26 | private toggleFindLastFreeWorkerNodeKey: boolean = false |
| 27 | /** @inheritDoc */ |
| 28 | public readonly taskStatisticsRequirements: TaskStatisticsRequirements = { |
| 29 | runTime: { |
| 30 | aggregate: false, |
| 31 | average: false, |
| 32 | median: false |
| 33 | }, |
| 34 | waitTime: { |
| 35 | aggregate: false, |
| 36 | average: false, |
| 37 | median: false |
| 38 | }, |
| 39 | elu: false |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * Constructs a worker choice strategy bound to the pool. |
| 44 | * |
| 45 | * @param pool - The pool instance. |
| 46 | * @param opts - The worker choice strategy options. |
| 47 | */ |
| 48 | public constructor ( |
| 49 | protected readonly pool: IPool<Worker, Data, Response>, |
| 50 | protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 51 | ) { |
| 52 | this.choose = this.choose.bind(this) |
| 53 | } |
| 54 | |
| 55 | protected setTaskStatisticsRequirements ( |
| 56 | opts: WorkerChoiceStrategyOptions |
| 57 | ): void { |
| 58 | if ( |
| 59 | this.taskStatisticsRequirements.runTime.average && |
| 60 | opts.runTime?.median === true |
| 61 | ) { |
| 62 | this.taskStatisticsRequirements.runTime.average = false |
| 63 | this.taskStatisticsRequirements.runTime.median = opts.runTime |
| 64 | .median as boolean |
| 65 | } |
| 66 | if ( |
| 67 | this.taskStatisticsRequirements.runTime.median && |
| 68 | opts.runTime?.median === false |
| 69 | ) { |
| 70 | this.taskStatisticsRequirements.runTime.average = true |
| 71 | this.taskStatisticsRequirements.runTime.median = opts.runTime |
| 72 | .median as boolean |
| 73 | } |
| 74 | if ( |
| 75 | this.taskStatisticsRequirements.waitTime.average && |
| 76 | opts.waitTime?.median === true |
| 77 | ) { |
| 78 | this.taskStatisticsRequirements.waitTime.average = false |
| 79 | this.taskStatisticsRequirements.waitTime.median = opts.waitTime |
| 80 | .median as boolean |
| 81 | } |
| 82 | if ( |
| 83 | this.taskStatisticsRequirements.waitTime.median && |
| 84 | opts.waitTime?.median === false |
| 85 | ) { |
| 86 | this.taskStatisticsRequirements.waitTime.average = true |
| 87 | this.taskStatisticsRequirements.waitTime.median = opts.waitTime |
| 88 | .median as boolean |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /** @inheritDoc */ |
| 93 | public abstract reset (): boolean |
| 94 | |
| 95 | /** @inheritDoc */ |
| 96 | public abstract update (workerNodeKey: number): boolean |
| 97 | |
| 98 | /** @inheritDoc */ |
| 99 | public abstract choose (): number |
| 100 | |
| 101 | /** @inheritDoc */ |
| 102 | public abstract remove (workerNodeKey: number): boolean |
| 103 | |
| 104 | /** @inheritDoc */ |
| 105 | public setOptions (opts: WorkerChoiceStrategyOptions): void { |
| 106 | opts = opts ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 107 | this.setTaskStatisticsRequirements(opts) |
| 108 | this.opts = opts |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * Finds a free worker node key. |
| 113 | * |
| 114 | * @returns The free worker node key or `-1` if there is no free worker node. |
| 115 | */ |
| 116 | protected findFreeWorkerNodeKey (): number { |
| 117 | if (this.toggleFindLastFreeWorkerNodeKey) { |
| 118 | this.toggleFindLastFreeWorkerNodeKey = false |
| 119 | return this.findLastFreeWorkerNodeKey() |
| 120 | } |
| 121 | this.toggleFindLastFreeWorkerNodeKey = true |
| 122 | return this.findFirstFreeWorkerNodeKey() |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Gets the worker task runtime. |
| 127 | * If the task statistics require the average runtime, the average runtime is returned. |
| 128 | * If the task statistics require the median runtime , the median runtime is returned. |
| 129 | * |
| 130 | * @param workerNodeKey - The worker node key. |
| 131 | * @returns The worker task runtime. |
| 132 | */ |
| 133 | protected getWorkerTaskRunTime (workerNodeKey: number): number { |
| 134 | return this.taskStatisticsRequirements.runTime.median |
| 135 | ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median |
| 136 | : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Gets the worker task wait time. |
| 141 | * If the task statistics require the average wait time, the average wait time is returned. |
| 142 | * If the task statistics require the median wait time, the median wait time is returned. |
| 143 | * |
| 144 | * @param workerNodeKey - The worker node key. |
| 145 | * @returns The worker task wait time. |
| 146 | */ |
| 147 | protected getWorkerWaitTime (workerNodeKey: number): number { |
| 148 | return this.taskStatisticsRequirements.waitTime.median |
| 149 | ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median |
| 150 | : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average |
| 151 | } |
| 152 | |
| 153 | protected computeDefaultWorkerWeight (): number { |
| 154 | let cpusCycleTimeWeight = 0 |
| 155 | for (const cpu of cpus()) { |
| 156 | // CPU estimated cycle time |
| 157 | const numberOfDigits = cpu.speed.toString().length - 1 |
| 158 | const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits)) |
| 159 | cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits) |
| 160 | } |
| 161 | return Math.round(cpusCycleTimeWeight / cpus().length) |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Finds the first free worker node key based on the number of tasks the worker has applied. |
| 166 | * |
| 167 | * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned. |
| 168 | * |
| 169 | * If no free worker is found, `-1` is returned. |
| 170 | * |
| 171 | * @returns A worker node key if there is one, `-1` otherwise. |
| 172 | */ |
| 173 | private findFirstFreeWorkerNodeKey (): number { |
| 174 | return this.pool.workerNodes.findIndex(workerNode => { |
| 175 | return workerNode.workerUsage.tasks.executing === 0 |
| 176 | }) |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * Finds the last free worker node key based on the number of tasks the worker has applied. |
| 181 | * |
| 182 | * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned. |
| 183 | * |
| 184 | * If no free worker is found, `-1` is returned. |
| 185 | * |
| 186 | * @returns A worker node key if there is one, `-1` otherwise. |
| 187 | */ |
| 188 | private findLastFreeWorkerNodeKey (): number { |
| 189 | // It requires node >= 18.0.0: |
| 190 | // return this.workerNodes.findLastIndex(workerNode => { |
| 191 | // return workerNode.workerUsage.tasks.executing === 0 |
| 192 | // }) |
| 193 | for ( |
| 194 | let workerNodeKey = this.pool.workerNodes.length - 1; |
| 195 | workerNodeKey >= 0; |
| 196 | workerNodeKey-- |
| 197 | ) { |
| 198 | if ( |
| 199 | this.pool.workerNodes[workerNodeKey].workerUsage.tasks.executing === 0 |
| 200 | ) { |
| 201 | return workerNodeKey |
| 202 | } |
| 203 | } |
| 204 | return -1 |
| 205 | } |
| 206 | } |