src/utils/AsyncLock.ts

   1 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
   2
   3 import Queue from 'mnemonist/queue.js'
   4
   5 import { Constants } from './Constants.js'
   6
   7 export enum AsyncLockType {
   8   configuration = 'configuration',
   9   performance = 'performance',
  10 }
  11
  12 type ResolveType = (value: void | PromiseLike<void>) => void
  13
  14 export class AsyncLock {
  15   private static readonly asyncLocks = new Map<AsyncLockType, AsyncLock>()
  16   private acquired: boolean
  17   private readonly resolveQueue: Queue<ResolveType>
  18
  19   private constructor () {
  20     this.acquired = false
  21     // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
  22     this.resolveQueue = new Queue<ResolveType>()
  23   }
  24
  25   public static async runExclusive<T>(type: AsyncLockType, fn: () => T | Promise<T>): Promise<T> {
  26     return await AsyncLock.acquire(type)
  27       .then(fn)
  28       .finally(() => {
  29         AsyncLock.release(type).catch(Constants.EMPTY_FUNCTION)
  30       })
  31   }
  32
  33   private static async acquire (type: AsyncLockType): Promise<void> {
  34     const asyncLock = AsyncLock.getAsyncLock(type)
  35     if (!asyncLock.acquired) {
  36       asyncLock.acquired = true
  37       return
  38     }
  39     await new Promise<void>((resolve) => {
  40       // eslint-disable-next-line @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
  41       asyncLock.resolveQueue.enqueue(resolve)
  42     })
  43   }
  44
  45   private static async release (type: AsyncLockType): Promise<void> {
  46     const asyncLock = AsyncLock.getAsyncLock(type)
  47     // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
  48     if (asyncLock.resolveQueue.size === 0 && asyncLock.acquired) {
  49       asyncLock.acquired = false
  50       return
  51     }
  52     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion, @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-call, @typescript-eslint/no-unsafe-member-access
  53     const queuedResolve = asyncLock.resolveQueue.dequeue()!
  54     await new Promise<void>((resolve) => {
  55       // eslint-disable-next-line @typescript-eslint/no-unsafe-call
  56       queuedResolve()
  57       resolve()
  58     })
  59   }
  60
  61   private static getAsyncLock (type: AsyncLockType): AsyncLock {
  62     if (!AsyncLock.asyncLocks.has(type)) {
  63       AsyncLock.asyncLocks.set(type, new AsyncLock())
  64     }
  65     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  66     return AsyncLock.asyncLocks.get(type)!
  67   }
  68 }