-import type { IPoolInternal } from '../pool-internal'
-import { PoolType } from '../pool-internal'
-import type { IPoolWorker } from '../pool-worker'
+import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import type { IPool } from '../pool'
+import type { IWorker } from '../worker'
import type {
IWorkerChoiceStrategy,
- RequiredStatistics
+ RequiredStatistics,
+ WorkerChoiceStrategyOptions
} from './selection-strategies-types'
/**
- * Abstract worker choice strategy class.
+ * Worker choice strategy abstract base class.
*
* @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 response of execution. This can only be serializable data.
+ * @typeParam Response - Type of execution response. This can only be serializable data.
*/
export abstract class AbstractWorkerChoiceStrategy<
- Worker extends IPoolWorker,
- Data,
- Response
-> implements IWorkerChoiceStrategy<Worker> {
- /** {@inheritDoc} */
- public readonly isDynamicPool: boolean
- /** {@inheritDoc} */
- public requiredStatistics: RequiredStatistics = {
- runTime: false
+ Worker extends IWorker,
+ Data = unknown,
+ Response = unknown
+> implements IWorkerChoiceStrategy {
+ /**
+ * Toggles finding the last free worker node key.
+ */
+ private toggleFindLastFreeWorkerNodeKey: boolean = false
+ /** @inheritDoc */
+ public readonly requiredStatistics: RequiredStatistics = {
+ runTime: false,
+ avgRunTime: false,
+ medRunTime: 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 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.isDynamicPool = this.pool.type === PoolType.DYNAMIC
+ this.choose = this.choose.bind(this)
+ }
+
+ protected checkOptions (opts: WorkerChoiceStrategyOptions): void {
+ if (this.requiredStatistics.avgRunTime && opts.medRunTime === true) {
+ this.requiredStatistics.avgRunTime = false
+ this.requiredStatistics.medRunTime = opts.medRunTime as boolean
+ }
+ if (this.requiredStatistics.medRunTime && opts.medRunTime === false) {
+ this.requiredStatistics.avgRunTime = true
+ this.requiredStatistics.medRunTime = opts.medRunTime as boolean
+ }
+ if (
+ opts.weights != null &&
+ Object.keys(opts.weights).length < this.pool.size
+ ) {
+ throw new Error(
+ 'Worker choice strategy options must have a weight for each worker node.'
+ )
+ }
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public abstract reset (): boolean
- /** {@inheritDoc} */
- public abstract choose (): Worker
+ /** @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.checkOptions(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()
+ }
+
+ /**
+ * Finds the first free worker node key based on the number of tasks the worker has applied.
+ *
+ * If a worker is found with `0` running 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.tasksUsage.running === 0
+ })
+ }
+
+ /**
+ * Finds the last free worker node key based on the number of tasks the worker has applied.
+ *
+ * If a worker is found with `0` running 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.tasksUsage.running === 0
+ // })
+ for (
+ let workerNodeKey = this.pool.workerNodes.length - 1;
+ workerNodeKey >= 0;
+ workerNodeKey--
+ ) {
+ if (this.pool.workerNodes[workerNodeKey].tasksUsage.running === 0) {
+ return workerNodeKey
+ }
+ }
+ return -1
+ }
}