1 import type { IPool
} from
'../pool.js'
2 import type { IWorker
} from
'../worker.js'
3 import { AbstractWorkerChoiceStrategy
} from
'./abstract-worker-choice-strategy.js'
5 type IWorkerChoiceStrategy
,
7 type TaskStatisticsRequirements
,
8 type WorkerChoiceStrategyOptions
,
9 } from
'./selection-strategies-types.js'
12 * Selects the next worker with a fair share scheduling algorithm.
13 * Loosely modeled after the fair queueing algorithm: https://en.wikipedia.org/wiki/Fair_queuing.
14 * @typeParam Worker - Type of worker which manages the strategy.
15 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
16 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
18 export class FairShareWorkerChoiceStrategy
<
19 Worker
extends IWorker
,
23 extends AbstractWorkerChoiceStrategy
<Worker
, Data
, Response
>
24 implements IWorkerChoiceStrategy
{
26 public readonly taskStatisticsRequirements
: TaskStatisticsRequirements
= {
46 pool
: IPool
<Worker
, Data
, Response
>,
47 opts
?: WorkerChoiceStrategyOptions
50 this.setTaskStatisticsRequirements(this.opts
)
54 public reset (): boolean {
55 for (const workerNode
of this.pool
.workerNodes
) {
56 delete workerNode
.strategyData
?.virtualTaskEndTimestamp
62 public update (workerNodeKey
: number): boolean {
63 this.pool
.workerNodes
[workerNodeKey
].strategyData
= {
64 virtualTaskEndTimestamp
:
65 this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey
),
71 public choose (): number | undefined {
72 this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey
)
73 this.nextWorkerNodeKey
= this.fairShareNextWorkerNodeKey()
74 return this.nextWorkerNodeKey
78 public remove (): boolean {
82 private fairShareNextWorkerNodeKey (): number | undefined {
83 return this.pool
.workerNodes
.reduce(
84 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
85 if (workerNode
.strategyData
?.virtualTaskEndTimestamp
== null) {
86 workerNode
.strategyData
= {
87 virtualTaskEndTimestamp
:
88 this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey
),
91 return this.isWorkerNodeReady(workerNodeKey
) &&
92 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
93 workerNode
.strategyData
.virtualTaskEndTimestamp
! <
94 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
95 workerNodes
[minWorkerNodeKey
].strategyData
!.virtualTaskEndTimestamp
!
104 * Computes the worker node key virtual task end timestamp.
105 * @param workerNodeKey - The worker node key.
106 * @returns The worker node key virtual task end timestamp.
108 private computeWorkerNodeVirtualTaskEndTimestamp (
109 workerNodeKey
: number
111 return this.getWorkerNodeVirtualTaskEndTimestamp(
113 this.getWorkerNodeVirtualTaskStartTimestamp(workerNodeKey
)
117 private getWorkerNodeVirtualTaskEndTimestamp (
118 workerNodeKey
: number,
119 workerNodeVirtualTaskStartTimestamp
: number
121 const workerNodeTaskExecutionTime
=
122 this.getWorkerNodeTaskWaitTime(workerNodeKey
) +
123 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
124 (this.opts
!.measurement
=== Measurements
.elu
125 ? this.getWorkerNodeTaskElu(workerNodeKey
)
126 : this.getWorkerNodeTaskRunTime(workerNodeKey
))
127 return workerNodeVirtualTaskStartTimestamp
+ workerNodeTaskExecutionTime
130 private getWorkerNodeVirtualTaskStartTimestamp (
131 workerNodeKey
: number
133 const virtualTaskEndTimestamp
=
134 this.pool
.workerNodes
[workerNodeKey
]?.strategyData
135 ?.virtualTaskEndTimestamp
136 const now
= performance
.now()
137 return now
< (virtualTaskEndTimestamp
?? Number.NEGATIVE_INFINITY
)
138 ? // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
139 virtualTaskEndTimestamp
!