refactor(core): CORE-15 type subtitles and own request and track lifetimes

packages/artplayer/src/subtitle/request.ts

@@ -0,0 +1,38 @@
+import type ResourceScope from '../lifecycle/scope'
+import { requestController } from '../lifecycle/resources'
+
+// Cancellation settles callers even when a fetch adapter ignores AbortSignal.
+export default class SubtitleRequest {
+  readonly scope: ResourceScope
+  readonly signal?: AbortSignal
+  private readonly cancelled: Promise<undefined>
+
+  constructor(parent: ResourceScope) {
+    this.scope = parent.child()
+    this.cancelled = new Promise((resolve) => {
+      this.scope.add(() => {
+        resolve(undefined)
+      })
+    })
+    this.signal = requestController(this.scope)?.signal
+  }
+
+  get active(): boolean {
+    return !this.scope.closed
+  }
+
+  cancel(): void {
+    this.scope.dispose()
+  }
+
+  async run<Result>(work: () => Promise<Result>): Promise<Result | undefined> {
+    if (!this.active)
+      return undefined
+    try {
+      return await Promise.race([work(), this.cancelled])
+    }
+    finally {
+      this.cancel()
+    }
+  }
+}