feat: allow changing repeating task interval and timeout (#2934)

To allow for changing the frequency and timeout of repeating tasks
add `setInterval` and `setTimeout` methods to the task.

This lets us repeat a task often to start with, then slow down the
repetition once a successful result has occured.

Author: achingbrain

packages/utils/src/repeating-task.ts

@@ -3,7 +3,34 @@ import { anySignal } from 'any-signal'
 import type { AbortOptions } from '@libp2p/interface'
 
 export interface RepeatingTask {
+  /**
+   * Update the interval after which the next iteration of the task will run.
+   *
+   * This is useful if, for example, you want to retry a task with a short rest
+   * duration until it succeeds, then periodically after that.
+   *
+   * This only affects the next iteration of the task, if it is currently
+   * running, that run will not be interrupted.
+   */
+  setInterval(ms: number): void
+
+  /**
+   * Update the amount of time a task will run before the passed abort signal
+   * will fire.
+   *
+   * * This only affects the next iteration of the task, if it is currently
+   * running, that run will not be interrupted.
+   */
+  setTimeout(ms: number): void
+
+  /**
+   * Start the task running
+   */
   start(): void
+
+  /**
+   * Stop the task running
+   */
   stop(): void
 }
 
@@ -16,6 +43,8 @@ export interface RepeatingTaskOptions {
 
   /**
    * Whether to schedule the task to run immediately
+   *
+   * @default false
    */
   runImmediately?: boolean
 }
@@ -54,6 +83,22 @@ export function repeatingTask (fn: (options?: AbortOptions) => void | Promise<vo
   let started = false
 
   return {
+    setInterval: (ms) => {
+      interval = ms
+
+      // maybe reschedule
+      if (timeout != null) {
+        clearTimeout(timeout)
+        timeout = setTimeout(runTask, interval)
+      }
+    },
+    setTimeout: (ms) => {
+      if (options == null) {
+        options = {}
+      }
+
+      options.timeout = ms
+    },
     start: () => {
       if (started) {
         return

packages/utils/test/repeating-task.spec.ts

@@ -67,4 +67,50 @@ describe('repeating-task', () => {
 
     expect(count).to.be.greaterThan(1)
   })
+
+  it('should update the interval of a task', async () => {
+    let count = 0
+
+    const task = repeatingTask(() => {
+      count++
+
+      if (count === 1) {
+        task.setInterval(2000)
+      }
+    }, 100)
+    task.start()
+
+    await delay(1000)
+
+    task.stop()
+
+    expect(count).to.equal(1)
+  })
+
+  it('should update the timeout of a task', async () => {
+    let count = 0
+
+    const task = repeatingTask(async (options) => {
+      // simulate a delay
+      await delay(100)
+
+      if (options?.signal?.aborted !== true) {
+        count++
+      }
+
+      if (count === 1) {
+        // set the task timeout to less than our simulated delay
+        task.setTimeout(10)
+      }
+    }, 100, {
+      timeout: 500
+    })
+    task.start()
+
+    await delay(1000)
+
+    task.stop()
+
+    expect(count).to.equal(1)
+  })
 })