✨ 添加下载功能

src-tauri/src/utils/format.rs

@@ -0,0 +1,21 @@
+// 格式化文件大小
+pub fn format_size(size: u64) -> String {
+    const KB: u64 = 1024;
+    const MB: u64 = KB * 1024;
+    const GB: u64 = MB * 1024;
+    
+    if size >= GB {
+        format!("{:.2} GB", size as f64 / GB as f64)
+    } else if size >= MB {
+        format!("{:.2} MB", size as f64 / MB as f64)
+    } else if size >= KB {
+        format!("{:.2} KB", size as f64 / KB as f64)
+    } else {
+        format!("{} B", size)
+    }
+}
+
+// 格式化下载速度
+pub fn format_speed(speed: u64) -> String {
+    format!("{}/s", format_size(speed))
+}