Fix issue causing high CPU usage when opening large images

Author: hbl917070

Tiefsee/Adapter.cs

@@ -1,4 +1,4 @@
-namespace Tiefsee;
+namespace Tiefsee;
 
 public static class Adapter {
 
@@ -102,4 +102,18 @@ private static void ThreadSleep(int interval) {
         }
     }
 
+    /// <summary>
+    /// 超時就強制結束
+    /// </summary>
+    /// <param name="timeoutSeconds"> 最長秒數 </param>
+    /// <param name="func"></param>
+    public static void RunWithTimeout(double timeoutSeconds, Action func) {
+        CancellationTokenSource cts = new();
+        cts.CancelAfter(TimeSpan.FromSeconds(timeoutSeconds)); // 設定超時時間
+
+        Task task = Task.Run(func, cts.Token); // 將 CancellationToken 傳遞給 Task.Run
+
+        task.Wait(cts.Token); // 等待任務完成或超時
+    }
+
 }

Tiefsee/Lib/ImgLib.cs

@@ -26,15 +26,10 @@ public static Bitmap GetFileIcon(string path, int size) {
 
         Bitmap icon = null;
 
-        CancellationTokenSource cts = new();
-        cts.CancelAfter(TimeSpan.FromSeconds(1)); // 設定超時時間為一秒
-
-        Task task = Task.Run(() => {
+        Adapter.RunWithTimeout(1, () => {
             // 取得圖片在Windows系統的縮圖
             icon = WindowsThumbnailProvider.GetThumbnail(path, size, size, ThumbnailOptions.ScaleUp);
-        }, cts.Token); // 將 CancellationToken 傳遞給 Task.Run
-
-        task.Wait(cts.Token); // 等待任務完成或超時
+        });
 
         return icon;
     }
@@ -801,9 +796,17 @@ public static string VipsResize(string path, double scale, string fileType, stri
         }
 
         NetVips.Image im = GetNetVips(img100, fileType);
-        using (NetVips.Image imR = im.Resize(scale: scale, kernel: Enums.Kernel.Lanczos3, gap: 4)) {
-            VipsSave(imR, filePath, "auto");
+
+        Enums.Kernel? kernel = Enums.Kernel.Lanczos3;
+        double? gap = 4;
+        // 如果圖片太大，就使用計算成本較低的 最近鄰法
+        if (im.Width > 30000 || im.Height > 30000) {
+            kernel = Enums.Kernel.Nearest;
+            gap = null;
         }
+        using NetVips.Image imR = im.Resize(scale: scale, kernel: kernel, gap: gap);
+        VipsSave(imR, filePath, "auto");
+
         StartWindow.isRunGC = true; // 定時執行GC
 
         return filePath;

Tiefsee/Server/WebServerController.cs

@@ -108,18 +108,20 @@ void ImgVipsInit(RequestData d) {
         //bool is304 = HeadersAdd304(d, path); //回傳檔案時加入快取的Headers
         //if (is304 == true) { return; }
 
-        for (int i = 0; i < arType.Length; i++) {
-            string type = arType[i];
+        Adapter.RunWithTimeout(60, () => {
+            for (int i = 0; i < arType.Length; i++) {
+                string type = arType[i];
 
-            try {
-                imgInfo = ImgLib.GetImgInitInfo(path, type, type);
-            }
-            catch { }
+                try {
+                    imgInfo = ImgLib.GetImgInitInfo(path, type, type);
+                }
+                catch { }
 
-            if (imgInfo.width != 0) {
-                break;
+                if (imgInfo.width != 0) {
+                    break;
+                }
             }
-        }
+        });
 
         json = JsonSerializer.Serialize(imgInfo);
         WriteString(d, json); // 回傳輸出的檔案路徑
@@ -139,8 +141,11 @@ void ImgVipsResize(RequestData d) {
         bool is304 = HeadersAdd304(d, path); // 回傳檔案時加入快取的Headers
         if (is304) { return; }
 
-        string imgPath = ImgLib.VipsResize(path, scale, fileType, vipsType);
-        WriteFile(d, imgPath); // 回傳檔案
+        Adapter.RunWithTimeout(60, () => {
+            string imgPath = ImgLib.VipsResize(path, scale, fileType, vipsType);
+            WriteFile(d, imgPath); // 回傳檔案
+        });
+
     }
 
     /// <summary>
@@ -374,27 +379,46 @@ private void GetFileIcon(RequestData d) {
         bool is304 = HeadersAdd304(d, path); // 回傳檔案時加入快取的 Headers
         if (is304) { return; }
 
+        Bitmap icon = null;
+
         try {
-            using Bitmap icon = ImgLib.GetFileIcon(path, size);
-            if (icon == null) { return; }
+            icon = ImgLib.GetFileIcon(path, size);
+        }
+        catch { }
+
+        // 如果取得失敗，就等待 1 秒後再試一次
+        if (icon == null) {
+            Thread.Sleep(1000);
+            try {
+                icon = ImgLib.GetFileIcon(path, size);
+            }
+            catch { }
+        }
+
+        // 如果 2 次都取得失敗，就返回 500 錯誤
+        if (icon == null) {
+            d.context.Response.StatusCode = 500;
+            WriteString(d, "500");
+            return;
+        }
 
-            using (Stream input = new MemoryStream()) {
+        try {
+            using Stream input = new MemoryStream();
 
-                icon.Save(input, System.Drawing.Imaging.ImageFormat.Png);
-                input.Position = 0;
+            icon.Save(input, System.Drawing.Imaging.ImageFormat.Png);
+            input.Position = 0;
 
-                d.context.Response.ContentLength64 = input.Length;
+            d.context.Response.ContentLength64 = input.Length;
 
-                if (d.context.Request.HttpMethod != "HEAD") {
-                    byte[] buffer = new byte[1024 * 16];
-                    int nbytes;
-                    while ((nbytes = input.Read(buffer, 0, buffer.Length)) > 0) {
-                        // context.Response.SendChunked = input.Length > 1024 * 16;
-                        d.context.Response.OutputStream.Write(buffer, 0, nbytes);
-                    }
+            if (d.context.Request.HttpMethod != "HEAD") {
+                byte[] buffer = new byte[1024 * 16];
+                int nbytes;
+                while ((nbytes = input.Read(buffer, 0, buffer.Length)) > 0) {
+                    // context.Response.SendChunked = input.Length > 1024 * 16;
+                    d.context.Response.OutputStream.Write(buffer, 0, nbytes);
                 }
             }
-
+            icon.Dispose();
         }
         catch {
             d.context.Response.StatusCode = 500;

Www/ts/Tiefseeview.ts

@@ -2627,6 +2627,7 @@ class Tiefseeview {
 
             let _w = toNumber(dom_data.style.width); // 原始圖片大小(旋轉前的大小)
             let _h = toNumber(dom_data.style.height);
+            if (_w === 0 || _h === 0) { return; }
             let _margin = 35; // 多繪製的區域
             let _scale = _w / getOriginalWidth(); // 目前的 圖片縮放比例
             let radio_can = 1;
@@ -2726,6 +2727,18 @@ class Tiefseeview {
                     dWidth: dWidth, dHeight: dHeight
                 }
 
+                // 如果圖片大於 canvas 的最大限制，就改用 <img> 來渲染
+                let nowWidth = can.width;
+                let nowHeight = can.height;
+                if (nowWidth > 65535 || nowHeight > 65535 || nowWidth * nowHeight > 265690000) {
+                    console.log("圖片過大，無法渲染", url);
+                    setDataType("img");
+                    await loadImg(url);
+                    // 載入圖片後必須重新設定大小
+                    setDataSize(dom_data.offsetWidth);
+                    return;
+                }
+
                 // if (sx < 0) { sx = 0 }
                 // if (sy < 0) { sy = 0 }
                 // if (sWidth > getOriginalWidth()) { sWidth = getOriginalWidth() }