✨ 添加后端内部轮询

src-tauri/src/utils/download_manager.rs

@@ -17,6 +17,7 @@ pub struct DownloadManager {
     aria2_port: Arc<Mutex<u16>>,
     aria2_pid: Arc<Mutex<Option<u32>>>,
     installing: Arc<AtomicBool>,
+    last_get_downloads: Arc<Mutex<Option<std::time::Instant>>>,
 }
 
 impl DownloadManager {
@@ -28,11 +29,40 @@ impl DownloadManager {
             aria2_port: Arc::new(Mutex::new(5144)),
             aria2_pid: Arc::new(Mutex::new(None)),
             installing: Arc::new(AtomicBool::new(false)),  // 初始化为 false
+            last_get_downloads: Arc::new(Mutex::new(None)),
         }
     }
 
-    // 获取所有下载任务
     pub async fn get_downloads(&self) -> Result<Vec<DownloadTaskResponse>, String> {
+        // 检查是否需要更新最后调用时间，并在作用域内立即释放锁
+        let should_skip_update = {
+            if let Ok(last_call) = self.last_get_downloads.lock() {
+                if let Some(last_time) = *last_call {
+                    last_time.elapsed().as_secs_f32() < 1.0
+                } else {
+                    false
+                }
+            } else {
+                false
+            }
+        };
+
+        if should_skip_update {
+            return self.get_downloads_internal().await;
+        }
+
+        // 更新最后调用时间，并在作用域内立即释放锁
+        {
+            if let Ok(mut last_call) = self.last_get_downloads.lock() {
+                *last_call = Some(std::time::Instant::now());
+            }
+        }
+
+        self.get_downloads_internal().await
+    }
+
+    // 获取所有下载任务
+    async fn get_downloads_internal(&self) -> Result<Vec<DownloadTaskResponse>, String> {
         // 获取队列中的任务信息并立即克隆所需数据，然后释放锁
         let tasks_clone: Vec<DownloadTask>;
         let aria2_started;
@@ -502,4 +532,13 @@ impl DownloadManager {
             Err(error_msg)
         }
     }
+
+    // 检查是否有下载任务
+    pub fn has_downloads(&self) -> bool {
+        if let Ok(downloads) = self.download_queue.lock() {
+            !downloads.is_empty()
+        } else {
+            false
+        }
+    }
 }