Fix 100% CPU on startup with large clipboard history

libdiodon/image-clipboard-item.vala

@@ -29,6 +29,7 @@ namespace Diodon
         private ClipboardType _clipboard_type;
         private string _checksum; // checksum to identify pic content
         private Gdk.Pixbuf _pixbuf;
+        private ByteArray? _raw_payload; // kept for lazy pixbuf loading
         private string _label;
         private string? _origin;
         private DateTime _date_copied;
@@ -61,11 +62,17 @@ namespace Diodon
             _origin = origin;
             _date_copied = date_copied;
 
+            // Extract dimensions and checksum without keeping full pixbuf
+            // in memory. Store raw payload for lazy decoding when needed.
             Gdk.PixbufLoader loader = new Gdk.PixbufLoader();
             loader.write(payload.data);
             loader.close();
             Gdk.Pixbuf pixbuf = loader.get_pixbuf();
             extract_pixbuf_info(pixbuf);
+
+            // Keep payload for lazy reload, release full pixbuf
+            _raw_payload = payload;
+            _pixbuf = null;
         }
 
         /**
@@ -123,7 +130,7 @@ namespace Diodon
         public Icon get_icon()
         {
             try {
-                File file = save_tmp_pixbuf(_pixbuf);
+                File file = save_tmp_pixbuf(ensure_pixbuf());
                 FileIcon icon = new FileIcon(file);
                 return icon;
             } catch(Error e) {
@@ -146,7 +153,7 @@ namespace Diodon
 	     */
         public Gtk.Image? get_image()
         {
-            Gdk.Pixbuf pixbuf_preview = create_scaled_pixbuf(_pixbuf);
+            Gdk.Pixbuf pixbuf_preview = create_scaled_pixbuf(ensure_pixbuf());
             return new Gtk.Image.from_pixbuf(pixbuf_preview);
         }
 
@@ -155,8 +162,11 @@ namespace Diodon
 	     */
         public ByteArray? get_payload() throws GLib.Error
         {
+            if (_raw_payload != null) {
+                return _raw_payload;
+            }
             uint8[] buffer;
-            _pixbuf.save_to_buffer(out buffer, "png");
+            ensure_pixbuf().save_to_buffer(out buffer, "png");
             return new ByteArray.take(buffer);
         }
 
@@ -173,7 +183,7 @@ namespace Diodon
 	     */
         public void to_clipboard(Gtk.Clipboard clipboard)
         {
-             clipboard.set_image(_pixbuf);
+             clipboard.set_image(ensure_pixbuf());
              clipboard.store();
         }
 
@@ -219,6 +229,31 @@ namespace Diodon
             _pixbuf = pixbuf;
         }
 
+        /**
+         * Lazily loads the full pixbuf from raw payload when needed.
+         * Items loaded from Zeitgeist only keep the raw payload until
+         * the pixbuf is actually required (e.g. paste or icon display).
+         *
+         * @return decoded pixbuf
+         */
+        private Gdk.Pixbuf ensure_pixbuf()
+        {
+            if (_pixbuf != null) {
+                return _pixbuf;
+            }
+
+            try {
+                Gdk.PixbufLoader loader = new Gdk.PixbufLoader();
+                loader.write(_raw_payload.data);
+                loader.close();
+                _pixbuf = loader.get_pixbuf();
+            } catch (Error e) {
+                warning("Failed to decode image payload: %s", e.message);
+                _pixbuf = new Gdk.Pixbuf(Gdk.Colorspace.RGB, false, 8, 1, 1);
+            }
+            return _pixbuf;
+        }
+
         /**
          * Create a menu icon size scaled pix buf
          *

libdiodon/text-clipboard-item.vala

@@ -48,12 +48,20 @@ namespace Diodon
             _date_copied = date_copied;
             _checksum = Checksum.compute_for_string(ChecksumType.SHA1, _text);
 
-            // label should not be longer than 50 letters
-            _label = _text;
+            // Truncate early to avoid processing large strings.
+            // Vala's string.replace() uses g_regex_replace_literal() internally
+            // which runs the entire string through PCRE2. For large clipboard
+            // items (e.g. 74KB of text), this causes excessive CPU usage.
+            // 200 bytes is enough to contain 50 UTF-8 chars (max 4 bytes each).
+            string label_text = _text;
+            if (label_text.length > 200) {
+                label_text = label_text.substring(0, 200);
+            }
+            _label = string.joinv(" ", label_text.split("\n"));
             if (_label.char_count() > 50) {
-                _label = _label.substring(0, 50) + "...";
+                long index_char = _label.index_of_nth_char(50);
+                _label = _label.substring(0, index_char) + "...";
             }
-            _label = _label.replace("\n", " ");
         }
 
         /**