合并资源流式响应

async function sequentialCombine(urls, destination) {
  try {
    // 按顺序处理每个URL
    for (let i = 0; i < urls.length; i++) {
      const url = urls[i];

      // 获取当前片段
      const response = await fetch(url);

      if (!response.ok) {
        console.error(`获取视频片段失败: ${url}, 状态码: ${response.status}`);
        continue;
      }

      // 获取可读流
      const readable = response.body;

      // 立即执行pipeTo，将当前片段写入目标流
      try {
        await readable.pipeTo(destination, {
          preventClose: true // 保持流开放以便后续写入
        });
      } catch (e) {
        console.error(`流处理错误 (${url}): ${e.message}`);
      }
    }
  } catch (err) {
    console.error(`合并视频流错误: ${err.message}`);
  } finally {
    // 完成所有片段处理后关闭流
    const writer = destination.getWriter();
    writer.close();
    writer.releaseLock();
  }
}

async function handleRequest(request) {
  // 视频片段地址
  const urls = [
    'https://vod.example.com/stream-01.mov',
    'https://vod.example.comm/stream-02.mov',
    'https://vod.example.com/stream-03.mov',
  ];

  // 创建转换流
  const { readable, writable } = new TransformStream();

  // 按顺序获取并合并视频片段
  sequentialCombine(urls, writable);

  // 返回合并后的视频流响应
  return new Response(readable, {
    headers: {
      'content-type': 'video/mp4',
    }
  });
}

// 监听fetch事件
addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request));
});