refactor(mediabunny): [PKG-MB-03] type inputs and cancel owned loads

packages/artplayer-proxy-mediabunny/src/load-session.ts

@@ -0,0 +1,77 @@
+import type { Input } from 'mediabunny'
+
+export default class LoadSession {
+  private active = true
+  private input: Input | null = null
+  private timers = new Set<ReturnType<typeof setTimeout>>()
+  private deadline: ReturnType<typeof setTimeout> | undefined
+  private controller = typeof AbortController === 'undefined' ? undefined : new AbortController()
+  private resolveCancellation!: () => void
+  private cancellation = new Promise<void>((resolve) => {
+    this.resolveCancellation = resolve
+  })
+
+  get signal(): AbortSignal | undefined {
+    return this.controller?.signal
+  }
+
+  own(input: Input): void {
+    if (this.active)
+      this.input = input
+    else input.dispose()
+  }
+
+  defer(callback: () => void): void {
+    if (!this.active)
+      return
+    const timer = setTimeout(() => {
+      this.timers.delete(timer)
+      if (this.active)
+        callback()
+    }, 0)
+    this.timers.add(timer)
+  }
+
+  async wait(operation: Promise<void>, milliseconds: number): Promise<void> {
+    try {
+      await Promise.race([
+        operation,
+        this.cancellation,
+        milliseconds > 0 ? this.timeout(milliseconds) : new Promise<void>(() => {}),
+      ])
+    }
+    finally {
+      if (this.deadline !== undefined) {
+        clearTimeout(this.deadline)
+        this.deadline = undefined
+      }
+    }
+  }
+
+  timeout(milliseconds: number): Promise<never> {
+    return new Promise((_, reject) => {
+      this.deadline = setTimeout(() => reject(new Error('Load timeout')), milliseconds)
+    })
+  }
+
+  disposeInput(): void {
+    const input = this.input
+    this.input = null
+    input?.dispose()
+  }
+
+  cancel(): void {
+    if (!this.active)
+      return
+    this.active = false
+    for (const timer of this.timers) clearTimeout(timer)
+    this.timers.clear()
+    if (this.deadline !== undefined) {
+      clearTimeout(this.deadline)
+      this.deadline = undefined
+    }
+    this.resolveCancellation()
+    this.controller?.abort()
+    this.disposeInput()
+  }
+}