Init commit

server/core/lib/schedulers/abstract-scheduler.ts

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+import Bluebird from 'bluebird'
+import { randomInt } from 'node:crypto'
+import { logger, loggerTagsFactory } from '../../helpers/logger.js'
+
+const lTags = loggerTagsFactory('schedulers')
+
+export abstract class AbstractScheduler {
+  protected abstract schedulerIntervalMs: number
+
+  private interval: NodeJS.Timeout
+  private firstRunTimeout: NodeJS.Timeout
+  private isRunning = false
+
+  private readonly randomRunOnEnable: boolean
+
+  constructor (options: {
+    randomRunOnEnable?: boolean
+  }) {
+    if (options?.randomRunOnEnable === true) {
+      this.randomRunOnEnable = true
+    }
+  }
+
+  enable () {
+    if (!this.schedulerIntervalMs) throw new Error('Interval is not correctly set.')
+
+    if (this.randomRunOnEnable === true) {
+      const randomDelay = randomInt(0, Math.floor(this.schedulerIntervalMs / 2))
+
+      this.firstRunTimeout = setTimeout(async () => {
+        try {
+          // execute() already handles errors
+          await this.execute()
+        } finally {
+          this.interval = setInterval(() => this.execute(), this.schedulerIntervalMs)
+        }
+      }, randomDelay)
+
+      return
+    }
+
+    this.interval = setInterval(() => this.execute(), this.schedulerIntervalMs)
+  }
+
+  disable () {
+    if (this.firstRunTimeout) {
+      clearTimeout(this.firstRunTimeout)
+      this.firstRunTimeout = undefined
+    }
+
+    if (this.interval) {
+      clearInterval(this.interval)
+      this.interval = undefined
+    }
+  }
+
+  async execute () {
+    if (this.isRunning === true) return
+    this.isRunning = true
+
+    try {
+      await this.internalExecute()
+    } catch (err) {
+      logger.error('Cannot execute ' + this.constructor.name + ' scheduler.', { err, ...lTags() })
+    } finally {
+      this.isRunning = false
+    }
+  }
+
+  protected abstract internalExecute (): Promise<any> | Bluebird<any>
+}