refactor(mediabunny): [PKG-MB-06] own audio clocks, buffers and context lifecycle

packages/artplayer-proxy-mediabunny/src/audio-task.ts

@@ -0,0 +1,50 @@
+export const CANCELLED = Symbol('cancelled')
+
+export default class AudioTask {
+  cancelled = false
+  private waits = new Set<() => void>()
+  private timers = new Map<ReturnType<typeof setTimeout>, (active: boolean) => void>()
+
+  wait<T>(pending: Promise<T>): Promise<T | typeof CANCELLED> {
+    return new Promise((resolve, reject) => {
+      const cancel = () => resolve(CANCELLED)
+      if (this.cancelled)
+        cancel()
+      else
+        this.waits.add(cancel)
+      pending.then((value) => {
+        this.waits.delete(cancel)
+        resolve(value)
+      }, (error) => {
+        this.waits.delete(cancel)
+        reject(error)
+      })
+    })
+  }
+
+  delay(ms: number): Promise<boolean> {
+    if (this.cancelled)
+      return Promise.resolve(false)
+    return new Promise((resolve) => {
+      const timer = setTimeout(() => {
+        this.timers.delete(timer)
+        resolve(!this.cancelled)
+      }, ms)
+      this.timers.set(timer, resolve)
+    })
+  }
+
+  cancel(): void {
+    if (this.cancelled)
+      return
+    this.cancelled = true
+    for (const cancel of this.waits)
+      cancel()
+    this.waits.clear()
+    for (const [timer, resolve] of this.timers) {
+      clearTimeout(timer)
+      resolve(false)
+    }
+    this.timers.clear()
+  }
+}