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.
15 * @typeParam Worker - Type of worker which manages the strategy.
16 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
17 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
19 export class FairShareWorkerChoiceStrategy
<
20 Worker
extends IWorker
,
24 extends AbstractWorkerChoiceStrategy
<Worker
, Data
, Response
>
25 implements IWorkerChoiceStrategy
{
27 public readonly taskStatisticsRequirements
: TaskStatisticsRequirements
= {
47 pool
: IPool
<Worker
, Data
, Response
>,
48 opts
?: WorkerChoiceStrategyOptions
51 this.setTaskStatisticsRequirements(this.opts
)
55 public reset (): boolean {
56 for (const workerNode
of this.pool
.workerNodes
) {
57 delete workerNode
.strategyData
?.virtualTaskEndTimestamp
63 public update (workerNodeKey
: number): boolean {
64 this.pool
.workerNodes
[workerNodeKey
].strategyData
= {
65 virtualTaskEndTimestamp
:
66 this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey
)
72 public choose (): number | undefined {
73 this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey
)
74 this.nextWorkerNodeKey
= this.fairShareNextWorkerNodeKey()
75 return this.nextWorkerNodeKey
79 public remove (): boolean {
83 private fairShareNextWorkerNodeKey (): number | undefined {
84 return this.pool
.workerNodes
.reduce(
85 (minWorkerNodeKey
, workerNode
, workerNodeKey
, workerNodes
) => {
86 if (workerNode
.strategyData
?.virtualTaskEndTimestamp
== null) {
87 workerNode
.strategyData
= {
88 virtualTaskEndTimestamp
:
89 this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey
)
92 return this.isWorkerNodeReady(workerNodeKey
) &&
93 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
94 workerNode
.strategyData
.virtualTaskEndTimestamp
! <
95 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
96 workerNodes
[minWorkerNodeKey
].strategyData
!.virtualTaskEndTimestamp
!
105 * Computes the worker node key virtual task end timestamp.
107 * @param workerNodeKey - The worker node key.
108 * @returns The worker node key virtual task end timestamp.
110 private computeWorkerNodeVirtualTaskEndTimestamp (
111 workerNodeKey
: number
113 return this.getWorkerNodeVirtualTaskEndTimestamp(
115 this.getWorkerNodeVirtualTaskStartTimestamp(workerNodeKey
)
119 private getWorkerNodeVirtualTaskEndTimestamp (
120 workerNodeKey
: number,
121 workerNodeVirtualTaskStartTimestamp
: number
123 const workerNodeTaskExecutionTime
=
124 this.getWorkerNodeTaskWaitTime(workerNodeKey
) +
125 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
126 (this.opts
!.measurement
=== Measurements
.elu
127 ? this.getWorkerNodeTaskElu(workerNodeKey
)
128 : this.getWorkerNodeTaskRunTime(workerNodeKey
))
129 return workerNodeVirtualTaskStartTimestamp
+ workerNodeTaskExecutionTime
132 private getWorkerNodeVirtualTaskStartTimestamp (
133 workerNodeKey
: number
135 const virtualTaskEndTimestamp
=
136 this.pool
.workerNodes
[workerNodeKey
]?.strategyData
137 ?.virtualTaskEndTimestamp
138 const now
= performance
.now()
139 return now
< (virtualTaskEndTimestamp
?? Number.NEGATIVE_INFINITY
)
140 ? // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
141 virtualTaskEndTimestamp
!