Commit | Line | Data |
---|---|---|
23ff945a JB |
1 | import type { AbstractPoolWorker } from '../abstract-pool-worker' |
2 | import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy' | |
3 | ||
4 | /** | |
5 | * Worker virtual task timestamp. | |
6 | */ | |
7 | type WorkerVirtualTaskTimestamp = { | |
8 | start: number | |
9 | end: number | |
10 | } | |
11 | ||
12 | /** | |
13 | * Selects the next worker with a fair share scheduling algorithm. | |
14 | * Loosely modeled after the fair queueing algorithm: https://en.wikipedia.org/wiki/Fair_queuing. | |
15 | * | |
16 | * @template Worker Type of worker which manages the strategy. | |
17 | * @template Data Type of data sent to the worker. This can only be serializable data. | |
18 | * @template Response Type of response of execution. This can only be serializable data. | |
19 | */ | |
20 | export class FairShareWorkerChoiceStrategy< | |
21 | Worker extends AbstractPoolWorker, | |
22 | Data, | |
23 | Response | |
24 | > extends AbstractWorkerChoiceStrategy<Worker, Data, Response> { | |
25 | /** | |
26 | * Worker last virtual task execution timestamp. | |
27 | */ | |
28 | private workerLastVirtualTaskTimestamp: Map< | |
29 | Worker, | |
30 | WorkerVirtualTaskTimestamp | |
31 | > = new Map<Worker, WorkerVirtualTaskTimestamp>() | |
32 | ||
33 | /** @inheritDoc */ | |
34 | public choose (): Worker { | |
35 | this.updateWorkerLastVirtualTaskTimestamp() | |
36 | let minWorkerVirtualTaskEndTimestamp = Infinity | |
37 | let chosenWorker!: Worker | |
38 | for (const worker of this.pool.workers) { | |
39 | const workerLastVirtualTaskEndTimestamp = | |
40 | this.workerLastVirtualTaskTimestamp.get(worker)?.end ?? 0 | |
41 | if ( | |
42 | workerLastVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp | |
43 | ) { | |
44 | minWorkerVirtualTaskEndTimestamp = workerLastVirtualTaskEndTimestamp | |
45 | chosenWorker = worker | |
46 | } | |
47 | } | |
48 | return chosenWorker | |
49 | } | |
50 | ||
51 | /** | |
52 | * Compute workers last virtual task timestamp. | |
53 | */ | |
54 | private updateWorkerLastVirtualTaskTimestamp () { | |
55 | for (const worker of this.pool.workers) { | |
56 | const workerVirtualTaskStartTimestamp = Math.max( | |
57 | Date.now(), | |
58 | this.workerLastVirtualTaskTimestamp.get(worker)?.end ?? 0 | |
59 | ) | |
60 | const workerVirtualTaskEndTimestamp = | |
61 | workerVirtualTaskStartTimestamp + | |
62 | (this.pool.getWorkerAverageTasksRunTime(worker) ?? 0) | |
63 | this.workerLastVirtualTaskTimestamp.set(worker, { | |
64 | start: workerVirtualTaskStartTimestamp, | |
65 | end: workerVirtualTaskEndTimestamp | |
66 | }) | |
67 | } | |
68 | } | |
69 | } |