优化IO问题，使用异步方案进行视频下载等操作。

utils/media_downloader.py

@@ -1,5 +1,7 @@
+import asyncio
 import os
-import requests
+import aiohttp
+import aiofiles
 import uuid
 from typing import Optional
 from urllib.parse import urlparse
@@ -24,7 +26,7 @@ class MediaDownloader:
         os.makedirs(self.download_dir, exist_ok=True)
         self.LOG.info(f"媒体下载目录: {self.download_dir}")
 
-    def download_media(self, url: str, file_type: str = None) -> Optional[str]:
+    async def download_media(self, url: str, file_type: str = None) -> Optional[str]:
         """
         下载媒体文件
         
@@ -42,7 +44,7 @@ class MediaDownloader:
             
             # 如果没有文件名或扩展名，则生成一个随机文件名
             if not filename or '.' not in filename:
-                ext = file_type if file_type else self._guess_file_type(url)
+                ext = file_type if file_type else await self._guess_file_type(url)
                 filename = f"{uuid.uuid4().hex}.{ext}" if ext else f"{uuid.uuid4().hex}"
             
             local_path = os.path.join(self.download_dir, filename)
@@ -50,18 +52,19 @@ class MediaDownloader:
             self.LOG.info(f"开始下载媒体文件: {url} -> {local_path}")
             
             # 下载文件
-            response = requests.get(url, stream=True, timeout=30)
-            response.raise_for_status()
-            
-            with open(local_path, 'wb') as f:
-                for chunk in response.iter_content(chunk_size=8192):
-                    if chunk:
-                        f.write(chunk)
+            async with aiohttp.ClientSession() as session:
+                async with session.get(url, timeout=30) as response:
+                    response.raise_for_status()
+                    
+                    async with aiofiles.open(local_path, 'wb') as f:
+                        async for chunk in response.content.iter_chunked(8192):
+                            if chunk:
+                                await f.write(chunk)
             
             self.LOG.info(f"媒体文件下载成功: {local_path}")
             
             # 下载成功后清理旧文件
-            self.clear_downloads()
+            await self.clear_downloads()
             
             return os.path.abspath(local_path)
             
@@ -69,7 +72,7 @@ class MediaDownloader:
             self.LOG.error(f"下载媒体文件失败: {url}, 错误: {str(e)}")
             return None
 
-    def _guess_file_type(self, url: str) -> Optional[str]:
+    async def _guess_file_type(self, url: str) -> Optional[str]:
         """
         从URL推断文件类型
         
@@ -97,21 +100,22 @@ class MediaDownloader:
                 return 'pdf'
             else:
                 # 检查Content-Type
-                response = requests.head(url, timeout=5)
-                content_type = response.headers.get('Content-Type', '')
-                
-                if 'image/jpeg' in content_type:
-                    return 'jpg'
-                elif 'image/png' in content_type:
-                    return 'png'
-                elif 'image/gif' in content_type:
-                    return 'gif'
+                async with aiohttp.ClientSession() as session:
+                    async with session.head(url, timeout=5) as response:
+                        content_type = response.headers.get('Content-Type', '')
+                        
+                        if 'image/jpeg' in content_type:
+                            return 'jpg'
+                        elif 'image/png' in content_type:
+                            return 'png'
+                        elif 'image/gif' in content_type:
+                            return 'gif'
                 
             return None
         except:
             return None
 
-    def clear_downloads(self, max_age_days: int = 3) -> None:
+    async def clear_downloads(self, max_age_days: int = 3) -> None:
         """
         清理超过指定天数的下载文件
         
@@ -136,7 +140,7 @@ class MediaDownloader:
                     # 如果文件超过最大保留时间，则删除
                     if file_age > max_age_seconds:
                         try:
-                            os.remove(file_path)
+                            await asyncio.to_thread(os.remove, file_path)
                             cleared_count += 1
                             self.LOG.debug(f"已删除过期文件: {file_path}")
                         except Exception as e: