src/utils/AsyncLock.ts

   1 // Partial Copyright Jerome Benoit. 2021-2023. All Rights Reserved.
   2
   3 import { Queue } from 'mnemonist'
   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     this.resolveQueue = new Queue<ResolveType>()
  22   }
  23
  24   public static async runExclusive<T>(type: AsyncLockType, fn: () => T | Promise<T>): Promise<T> {
  25     return await AsyncLock.acquire(type)
  26       .then(fn)
  27       .finally(() => {
  28         AsyncLock.release(type).catch(Constants.EMPTY_FUNCTION)
  29       })
  30   }
  31
  32   private static async acquire (type: AsyncLockType): Promise<void> {
  33     const asyncLock = AsyncLock.getAsyncLock(type)
  34     if (!asyncLock.acquired) {
  35       asyncLock.acquired = true
  36       return
  37     }
  38     await new Promise<void>((resolve) => {
  39       asyncLock.resolveQueue.enqueue(resolve)
  40     })
  41   }
  42
  43   private static async release (type: AsyncLockType): Promise<void> {
  44     const asyncLock = AsyncLock.getAsyncLock(type)
  45     if (asyncLock.resolveQueue.size === 0 && asyncLock.acquired) {
  46       asyncLock.acquired = false
  47       return
  48     }
  49     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  50     const queuedResolve = asyncLock.resolveQueue.dequeue()!
  51     await new Promise<void>((resolve) => {
  52       queuedResolve()
  53       resolve()
  54     })
  55   }
  56
  57   private static getAsyncLock (type: AsyncLockType): AsyncLock {
  58     if (!AsyncLock.asyncLocks.has(type)) {
  59       AsyncLock.asyncLocks.set(type, new AsyncLock())
  60     }
  61     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
  62     return AsyncLock.asyncLocks.get(type)!
  63   }
  64 }