-import type { AbstractPoolWorker } from '../abstract-pool-worker'
-import type { IPoolInternal } from '../pool-internal'
-import { PoolType } from '../pool-internal'
-import type { IWorkerChoiceStrategy } from './selection-strategies-types'
+import { cpus } from 'node:os'
+import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import type { IPool } from '../pool'
+import type { IWorker } from '../worker'
+import type {
+ IWorkerChoiceStrategy,
+ TaskStatisticsRequirements,
+ WorkerChoiceStrategyOptions
+} from './selection-strategies-types'
/**
- * Abstract worker choice strategy class.
+ * Worker choice strategy abstract base class.
*
- * @template Worker Type of worker which manages the strategy.
- * @template Data Type of data sent to the worker. This can only be serializable data.
- * @template Response Type of response of execution. This can only be serializable data.
+ * @typeParam Worker - Type of worker which manages the strategy.
+ * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
+ * @typeParam Response - Type of execution response. This can only be serializable data.
*/
export abstract class AbstractWorkerChoiceStrategy<
- Worker extends AbstractPoolWorker,
- Data,
- Response
-> implements IWorkerChoiceStrategy<Worker> {
- /** @inheritdoc */
- public isDynamicPool: boolean = this.pool.type === PoolType.DYNAMIC
+ Worker extends IWorker,
+ Data = unknown,
+ Response = unknown
+> implements IWorkerChoiceStrategy {
+ /**
+ * Toggles finding the last free worker node key.
+ */
+ private toggleFindLastFreeWorkerNodeKey: boolean = false
+ /** @inheritDoc */
+ public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+ runTime: {
+ aggregate: false,
+ average: false,
+ median: false
+ },
+ waitTime: {
+ aggregate: false,
+ average: false,
+ median: false
+ },
+ elu: {
+ aggregate: false,
+ average: false,
+ median: false
+ }
+ }
/**
- * Constructs a worker choice strategy attached to the pool.
+ * Constructs a worker choice strategy bound to the pool.
*
- * @param pool The pool instance.
+ * @param pool - The pool instance.
+ * @param opts - The worker choice strategy options.
*/
public constructor (
- protected readonly pool: IPoolInternal<Worker, Data, Response>
- ) {}
+ protected readonly pool: IPool<Worker, Data, Response>,
+ protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ ) {
+ this.choose = this.choose.bind(this)
+ }
+
+ protected setTaskStatisticsRequirements (
+ opts: WorkerChoiceStrategyOptions
+ ): void {
+ if (
+ this.taskStatisticsRequirements.runTime.average &&
+ opts.runTime?.median === true
+ ) {
+ this.taskStatisticsRequirements.runTime.average = false
+ this.taskStatisticsRequirements.runTime.median = opts.runTime
+ .median as boolean
+ }
+ if (
+ this.taskStatisticsRequirements.runTime.median &&
+ opts.runTime?.median === false
+ ) {
+ this.taskStatisticsRequirements.runTime.average = true
+ this.taskStatisticsRequirements.runTime.median = opts.runTime
+ .median as boolean
+ }
+ if (
+ this.taskStatisticsRequirements.waitTime.average &&
+ opts.waitTime?.median === true
+ ) {
+ this.taskStatisticsRequirements.waitTime.average = false
+ this.taskStatisticsRequirements.waitTime.median = opts.waitTime
+ .median as boolean
+ }
+ if (
+ this.taskStatisticsRequirements.waitTime.median &&
+ opts.waitTime?.median === false
+ ) {
+ this.taskStatisticsRequirements.waitTime.average = true
+ this.taskStatisticsRequirements.waitTime.median = opts.waitTime
+ .median as boolean
+ }
+ if (
+ this.taskStatisticsRequirements.elu.average &&
+ opts.elu?.median === true
+ ) {
+ this.taskStatisticsRequirements.elu.average = false
+ this.taskStatisticsRequirements.elu.median = opts.elu.median as boolean
+ }
+ if (
+ this.taskStatisticsRequirements.elu.median &&
+ opts.elu?.median === false
+ ) {
+ this.taskStatisticsRequirements.elu.average = true
+ this.taskStatisticsRequirements.elu.median = opts.elu.median as boolean
+ }
+ }
+
+ /** @inheritDoc */
+ public abstract reset (): boolean
+
+ /** @inheritDoc */
+ public abstract update (workerNodeKey: number): boolean
+
+ /** @inheritDoc */
+ public abstract choose (): number
+
+ /** @inheritDoc */
+ public abstract remove (workerNodeKey: number): boolean
+
+ /** @inheritDoc */
+ public setOptions (opts: WorkerChoiceStrategyOptions): void {
+ opts = opts ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ this.setTaskStatisticsRequirements(opts)
+ this.opts = opts
+ }
+
+ /**
+ * Finds a free worker node key.
+ *
+ * @returns The free worker node key or `-1` if there is no free worker node.
+ */
+ protected findFreeWorkerNodeKey (): number {
+ if (this.toggleFindLastFreeWorkerNodeKey) {
+ this.toggleFindLastFreeWorkerNodeKey = false
+ return this.findLastFreeWorkerNodeKey()
+ }
+ this.toggleFindLastFreeWorkerNodeKey = true
+ return this.findFirstFreeWorkerNodeKey()
+ }
+
+ /**
+ * Gets the worker task runtime.
+ * If the task statistics require the average runtime, the average runtime is returned.
+ * If the task statistics require the median runtime , the median runtime is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task runtime.
+ */
+ protected getWorkerTaskRunTime (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.runTime.median
+ ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median
+ : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average
+ }
+
+ /**
+ * Gets the worker task wait time.
+ * If the task statistics require the average wait time, the average wait time is returned.
+ * If the task statistics require the median wait time, the median wait time is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task wait time.
+ */
+ protected getWorkerTaskWaitTime (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.waitTime.median
+ ? this.pool.workerNodes[workerNodeKey].workerUsage.runTime.median
+ : this.pool.workerNodes[workerNodeKey].workerUsage.runTime.average
+ }
+
+ /**
+ * Gets the worker task ELU.
+ * If the task statistics require the average ELU, the average ELU is returned.
+ * If the task statistics require the median ELU, the median ELU is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task ELU.
+ */
+ protected getWorkerTaskElu (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.elu.median
+ ? this.pool.workerNodes[workerNodeKey].workerUsage.elu.active.median
+ : this.pool.workerNodes[workerNodeKey].workerUsage.elu.active.average
+ }
+
+ protected computeDefaultWorkerWeight (): number {
+ let cpusCycleTimeWeight = 0
+ for (const cpu of cpus()) {
+ // CPU estimated cycle time
+ const numberOfDigits = cpu.speed.toString().length - 1
+ const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits))
+ cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits)
+ }
+ return Math.round(cpusCycleTimeWeight / cpus().length)
+ }
+
+ /**
+ * Finds the first free worker node key based on the number of tasks the worker has applied.
+ *
+ * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned.
+ *
+ * If no free worker is found, `-1` is returned.
+ *
+ * @returns A worker node key if there is one, `-1` otherwise.
+ */
+ private findFirstFreeWorkerNodeKey (): number {
+ return this.pool.workerNodes.findIndex(workerNode => {
+ return workerNode.workerUsage.tasks.executing === 0
+ })
+ }
- /** @inheritdoc */
- public abstract choose (): Worker
+ /**
+ * Finds the last free worker node key based on the number of tasks the worker has applied.
+ *
+ * If a worker is found with `0` executing tasks, it is detected as free and its worker node key is returned.
+ *
+ * If no free worker is found, `-1` is returned.
+ *
+ * @returns A worker node key if there is one, `-1` otherwise.
+ */
+ private findLastFreeWorkerNodeKey (): number {
+ // It requires node >= 18.0.0:
+ // return this.workerNodes.findLastIndex(workerNode => {
+ // return workerNode.workerUsage.tasks.executing === 0
+ // })
+ for (
+ let workerNodeKey = this.pool.workerNodes.length - 1;
+ workerNodeKey >= 0;
+ workerNodeKey--
+ ) {
+ if (
+ this.pool.workerNodes[workerNodeKey].workerUsage.tasks.executing === 0
+ ) {
+ return workerNodeKey
+ }
+ }
+ return -1
+ }
}