chromium

public/s/js/f0ckm.js

@@ -184,61 +184,69 @@ window.cancelAnimFrame = (function () {
         return;
     }
 
-    if (!lazyObserver) {
+    // Chromium fix: always disconnect the old observer before creating a new one.
-        lazyObserver = new IntersectionObserver((entries) => {
+    // Chromium holds detached DOM nodes in an IntersectionObserver alive much longer
-            entries.forEach(entry => {
+    // than Firefox does. If we reuse a stale observer after an AJAX content swap,
-                if (entry.isIntersecting) {
+    // Chromium can fire callbacks for old detached nodes, causing duplicate image
-                    const thumb = entry.target;
+    // fetches and flooding the network. Disconnecting releases those references.
-                    let bg = thumb.dataset.bg;
+    if (lazyObserver) {
-                    if (bg && !thumb.classList.contains('loaded')) {
+        lazyObserver.disconnect();
-                        const mode = thumb.getAttribute('data-mode');
+        lazyObserver = null;
-                        const blurNsfw = localStorage.getItem('blurNsfw') === 'true';
-                        const blurNsfl = localStorage.getItem('blurNsfl') === 'true';
-                        const blurSfw = localStorage.getItem('blurSfw') === 'true';
-                        const blurUntagged = localStorage.getItem('blurUntagged') === 'true';
-                        
-                        let shouldBlurThis = false;
-                        if (mode === 'nsfw') shouldBlurThis = blurNsfw;
-                        else if (mode === 'nsfl') shouldBlurThis = blurNsfl;
-                        else if (mode === 'sfw') shouldBlurThis = blurSfw;
-                        else if (mode === 'null' || !mode) shouldBlurThis = blurUntagged;
-                        
-                        if (shouldBlurThis && !thumb.classList.contains('revealed')) {
-                            bg = bg.replace('.webp', '_blur.webp');
-                        }
-
-                        bg = window.applyThumbCacheBust(bg);
-                        const img = new Image();
-                        img.onload = () => {
-                            thumb.style.backgroundImage = `url('${bg}')`;
-                            thumb.classList.add('loaded');
-                            thumb.classList.remove('lazy-thumb');
-                        };
-                        img.onerror = () => {
-                            const retries = parseInt(thumb.dataset.retries || '0');
-                            if (retries < 3) {
-                                thumb.dataset.retries = retries + 1;
-                                setTimeout(() => {
-                                    img.src = bg + '?r=' + Date.now();
-                                }, 1000);
-                            } else {
-                                // All retries exhausted — show fallback for audio items
-                                const mime = thumb.dataset.mime || '';
-                                if (mime.startsWith('audio/')) {
-                                    thumb.style.backgroundImage = `url('/s/img/audio.webp')`;
-                                    thumb.classList.add('thumb-fallback');
-                                }
-                                thumb.classList.remove('lazy-thumb');
-                            }
-                        };
-                        img.src = bg;
-                    }
-                    lazyObserver.unobserve(thumb);
-                }
-            });
-        }, { rootMargin: '300px 0px', threshold: 0.01 });
     }
 
+    lazyObserver = new IntersectionObserver((entries) => {
+        entries.forEach(entry => {
+            if (entry.isIntersecting) {
+                const thumb = entry.target;
+                let bg = thumb.dataset.bg;
+                if (bg && !thumb.classList.contains('loaded')) {
+                    const mode = thumb.getAttribute('data-mode');
+                    const blurNsfw = localStorage.getItem('blurNsfw') === 'true';
+                    const blurNsfl = localStorage.getItem('blurNsfl') === 'true';
+                    const blurSfw = localStorage.getItem('blurSfw') === 'true';
+                    const blurUntagged = localStorage.getItem('blurUntagged') === 'true';
+                    
+                    let shouldBlurThis = false;
+                    if (mode === 'nsfw') shouldBlurThis = blurNsfw;
+                    else if (mode === 'nsfl') shouldBlurThis = blurNsfl;
+                    else if (mode === 'sfw') shouldBlurThis = blurSfw;
+                    else if (mode === 'null' || !mode) shouldBlurThis = blurUntagged;
+                    
+                    if (shouldBlurThis && !thumb.classList.contains('revealed')) {
+                        bg = bg.replace('.webp', '_blur.webp');
+                    }
+
+                    bg = window.applyThumbCacheBust(bg);
+                    const img = new Image();
+                    img.onload = () => {
+                        thumb.style.backgroundImage = `url('${bg}')`;
+                        thumb.classList.add('loaded');
+                        thumb.classList.remove('lazy-thumb');
+                    };
+                    img.onerror = () => {
+                        const retries = parseInt(thumb.dataset.retries || '0');
+                        if (retries < 3) {
+                            thumb.dataset.retries = retries + 1;
+                            setTimeout(() => {
+                                img.src = bg + '?r=' + Date.now();
+                            }, 1000);
+                        } else {
+                            // All retries exhausted — show fallback for audio items
+                            const mime = thumb.dataset.mime || '';
+                            if (mime.startsWith('audio/')) {
+                                thumb.style.backgroundImage = `url('/s/img/audio.webp')`;
+                                thumb.classList.add('thumb-fallback');
+                            }
+                            thumb.classList.remove('lazy-thumb');
+                        }
+                    };
+                    img.src = bg;
+                }
+                lazyObserver.unobserve(thumb);
+            }
+        });
+    }, { rootMargin: '300px 0px', threshold: 0.01 });
+
     // Nudge lazy loading on tab switch to prevent stuck skeletons in inactive tabs
     if (!window._lazyVisibilityBound) {
         window._lazyVisibilityBound = true;
@@ -254,7 +262,10 @@ window.cancelAnimFrame = (function () {
     }
 
     document.querySelectorAll('.lazy-thumb').forEach(thumb => {
-        if (!thumb.dataset.lazyObserved) {
+        // Reset lazyObserved on every initLazyLoading call so the fresh observer
+        // picks up all unloaded thumbs regardless of previous observation state.
+        delete thumb.dataset.lazyObserved;
+        if (!thumb.classList.contains('loaded')) {
             thumb.dataset.lazyObserved = 'true';
             lazyObserver.observe(thumb);
         }

src/index.mjs

@@ -535,6 +535,17 @@ process.on('uncaughtException', err => {
         }
         return;
       }
+      // Thumbnails (/t/) and covers (/ca/) are static WebP files that never change at a
+      // given URL — the client appends a ?t= cache-bust param when a thumb is regenerated.
+      // Without an explicit Cache-Control header, Chromium treats these as uncacheable and
+      // re-fetches every visible thumbnail on every AJAX navigation, causing severe lag.
+      // Firefox uses a more lenient heuristic and caches them anyway — hence the difference.
+      if (req.url.pathname.match(/^\/(t|ca)\//)) {
+        res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
+      } else if (req.url.pathname.match(/^\/(b|a|memes)\//)) {
+        // Full-size images and avatars: cache for 1 hour, re-validate after
+        res.setHeader('Cache-Control', 'public, max-age=3600');
+      }
       return;
     }
     const availableThemes = cfg.websrv.themes || ['amoled', 'atmos', 'f0ck', 'f0ck95d', 'iced', 'orange', 'p1nk', '4d'];