⚡ Bolt: Optimize render loop by pre-calculating properties

.jules/bolt.md

@@ -0,0 +1,4 @@
+
+## 2025-02-17 - Pre-calculating Expensive Runtime Properties for Render Loops
+**Learning:** Instantiating `new Date()`, date arithmetic, and multiple `toLowerCase()` string concatenations inside a hot loop (`renderPDFs` filter and `createPDFCard` mapping) creates a significant CPU bottleneck on the main thread, especially as the size of `pdfDatabase` grows.
+**Action:** Move all static and predictable calculations (search string indexing, date formatting, and boolean states like `_isNew`) to an initialization step (`prepareSearchIndex`) executed exactly once per document during data loading. The render loop can then fast-path using cheap boolean/string property lookups.

bolt_test.js

@@ -0,0 +1,10 @@
+const fs = require('fs');
+const script = fs.readFileSync('script.js', 'utf8');
+
+// We just do syntax checking
+try {
+  new Function(script);
+  console.log("Syntax OK");
+} catch (e) {
+  console.error("Syntax Error:", e);
+}

patch1.py

@@ -0,0 +1,49 @@
+import sys
+
+def apply_patch():
+    with open('script.js', 'r') as f:
+        content = f.read()
+
+    prepare_func = """
+/* =========================================
+   NEW: PERFORMANCE OPTIMIZATION (BOLT)
+   ========================================= */
+// ⚡ Bolt: Pre-calculating expensive runtime properties to speed up the render loop.
+function prepareSearchIndex(pdf) {
+    // 1. Handle dates efficiently
+    let uploadDateObj;
+    if (pdf.uploadDate && typeof pdf.uploadDate.toDate === 'function') {
+        uploadDateObj = pdf.uploadDate.toDate();
+    } else {
+        uploadDateObj = new Date(pdf.uploadDate);
+    }
+
+    // 2. Pre-calculate "New" badge (7 days)
+    const timeDiff = new Date() - uploadDateObj;
+    pdf._isNew = timeDiff < (7 * 24 * 60 * 60 * 1000);
+
+    // 3. Pre-format date string
+    pdf._formattedDate = uploadDateObj.toLocaleDateString('en-US', {
+        year: 'numeric', month: 'short', day: 'numeric'
+    });
+
+    // 4. Create a single combined lowercase string for O(1) search operations
+    const safeStr = (str) => (str || '').toString().toLowerCase();
+    pdf._searchStr = `${safeStr(pdf.title)} ${safeStr(pdf.description)} ${safeStr(pdf.category)} ${safeStr(pdf.author)}`;
+
+    return pdf;
+}
+"""
+    # Insert before loadPDFDatabase
+    target_str = "async function syncClassSwitcher() {"
+
+    if target_str in content:
+        content = content.replace(target_str, prepare_func + "\n" + target_str)
+        with open('script.js', 'w') as f:
+            f.write(content)
+        print("Patch applied successfully.")
+    else:
+        print("Could not find target string.")
+
+if __name__ == "__main__":
+    apply_patch()

patch2.py

@@ -0,0 +1,41 @@
+import sys
+
+def apply_patch():
+    with open('script.js', 'r') as f:
+        content = f.read()
+
+    # Apply to Cached Data
+    search_str1 = """        if (shouldUseCache) {
+            pdfDatabase = cachedData;"""
+    replace_str1 = """        if (shouldUseCache) {
+            // ⚡ Bolt: Apply pre-calculations to cached data
+            pdfDatabase = cachedData.map(pdf => prepareSearchIndex(pdf));"""
+
+    if search_str1 in content:
+        content = content.replace(search_str1, replace_str1)
+    else:
+        print("Could not find cache block.")
+
+    # Apply to Fresh Fetch
+    search_str2 = """        pdfDatabase = [];
+        snapshot.forEach(doc => {
+            pdfDatabase.push({ id: doc.id, ...doc.data() });
+        });"""
+    replace_str2 = """        pdfDatabase = [];
+        snapshot.forEach(doc => {
+            // ⚡ Bolt: Prepare search index immediately on fetch
+            let pdf = { id: doc.id, ...doc.data() };
+            pdfDatabase.push(prepareSearchIndex(pdf));
+        });"""
+
+    if search_str2 in content:
+        content = content.replace(search_str2, replace_str2)
+    else:
+        print("Could not find fresh fetch block.")
+
+    with open('script.js', 'w') as f:
+        f.write(content)
+    print("Patch 2 applied successfully.")
+
+if __name__ == "__main__":
+    apply_patch()

patch3.py

@@ -0,0 +1,60 @@
+import sys
+
+def apply_patch():
+    with open('script.js', 'r') as f:
+        content = f.read()
+
+    search_str = """    const filteredPdfs = pdfDatabase.filter(pdf => {
+        const matchesSemester = pdf.semester === currentSemester;
+
+        // NEW: Check if the PDF class matches the UI's current class selection
+        // Note: If old documents don't have this field, they will be hidden.
+        const matchesClass = pdf.class === currentClass;
+
+        let matchesCategory = false;
+        if (currentCategory === 'favorites') {
+            matchesCategory = favorites.includes(pdf.id);
+        } else {
+            matchesCategory = currentCategory === 'all' || pdf.category === currentCategory;
+        }
+
+        const matchesSearch = pdf.title.toLowerCase().includes(searchTerm) ||
+            pdf.description.toLowerCase().includes(searchTerm) ||
+            pdf.category.toLowerCase().includes(searchTerm) ||
+            pdf.author.toLowerCase().includes(searchTerm);
+
+        // Update return statement to include matchesClass
+        return matchesSemester && matchesClass && matchesCategory && matchesSearch;
+    });"""
+
+    replace_str = """    // ⚡ Bolt: Fast-path filtering using early returns and pre-calculated index
+    const filteredPdfs = pdfDatabase.filter(pdf => {
+        // 1. Cheap Equality Checks First
+        if (pdf.class !== currentClass) return false;
+        if (pdf.semester !== currentSemester) return false;
+
+        // 2. Category Check
+        if (currentCategory === 'favorites') {
+            if (!favorites.includes(pdf.id)) return false;
+        } else if (currentCategory !== 'all') {
+            if (pdf.category !== currentCategory) return false;
+        }
+
+        // 3. Expensive String Match Last (Using pre-calculated string)
+        if (searchTerm) {
+            return pdf._searchStr.includes(searchTerm);
+        }
+
+        return true;
+    });"""
+
+    if search_str in content:
+        content = content.replace(search_str, replace_str)
+        with open('script.js', 'w') as f:
+            f.write(content)
+        print("Patch 3 applied successfully.")
+    else:
+        print("Could not find renderPDFs filter block.")
+
+if __name__ == "__main__":
+    apply_patch()

patch4.py

@@ -0,0 +1,41 @@
+import sys
+
+def apply_patch():
+    with open('script.js', 'r') as f:
+        content = f.read()
+
+    search_str = """    const uploadDateObj = new Date(pdf.uploadDate);
+    const timeDiff = new Date() - uploadDateObj;
+    const isNew = timeDiff < (7 * 24 * 60 * 60 * 1000); // 7 days"""
+
+    replace_str = """    // ⚡ Bolt: Use pre-calculated values
+    const isNew = pdf._isNew;"""
+
+    if search_str in content:
+        content = content.replace(search_str, replace_str)
+        print("Patch 4 applied successfully (part 1).")
+    else:
+        print("Could not find new badge block.")
+
+    search_str2 = """    // Formatting Date
+    const formattedDate = new Date(pdf.uploadDate).toLocaleDateString('en-US', {
+        year: 'numeric', month: 'short', day: 'numeric'
+    });"""
+
+    replace_str2 = """    // Formatting Date
+    // ⚡ Bolt: Use pre-calculated date string
+    const formattedDate = pdf._formattedDate || new Date(pdf.uploadDate).toLocaleDateString('en-US', {
+        year: 'numeric', month: 'short', day: 'numeric'
+    });"""
+
+    if search_str2 in content:
+        content = content.replace(search_str2, replace_str2)
+        print("Patch 4 applied successfully (part 2).")
+    else:
+        print("Could not find formatted date block.")
+
+    with open('script.js', 'w') as f:
+        f.write(content)
+
+if __name__ == "__main__":
+    apply_patch()

script.js

@@ -382,6 +382,36 @@ window.changeSemester = function (sem) {
     renderPDFs();
 };
 
+
+/* =========================================
+   NEW: PERFORMANCE OPTIMIZATION (BOLT)
+   ========================================= */
+// ⚡ Bolt: Pre-calculating expensive runtime properties to speed up the render loop.
+function prepareSearchIndex(pdf) {
+    // 1. Handle dates efficiently
+    let uploadDateObj;
+    if (pdf.uploadDate && typeof pdf.uploadDate.toDate === 'function') {
+        uploadDateObj = pdf.uploadDate.toDate();
+    } else {
+        uploadDateObj = new Date(pdf.uploadDate);
+    }
+
+    // 2. Pre-calculate "New" badge (7 days)
+    const timeDiff = new Date() - uploadDateObj;
+    pdf._isNew = timeDiff < (7 * 24 * 60 * 60 * 1000);
+
+    // 3. Pre-format date string
+    pdf._formattedDate = uploadDateObj.toLocaleDateString('en-US', {
+        year: 'numeric', month: 'short', day: 'numeric'
+    });
+
+    // 4. Create a single combined lowercase string for O(1) search operations
+    const safeStr = (str) => (str || '').toString().toLowerCase();
+    pdf._searchStr = `${safeStr(pdf.title)} ${safeStr(pdf.description)} ${safeStr(pdf.category)} ${safeStr(pdf.author)}`;
+
+    return pdf;
+}
+
 async function syncClassSwitcher() {
     const classSelect = document.getElementById('classSelect');
     if (!classSelect) return;
@@ -450,7 +480,8 @@ async function loadPDFDatabase() {
         }
 
         if (shouldUseCache) {
-            pdfDatabase = cachedData;
+            // ⚡ Bolt: Apply pre-calculations to cached data
+            pdfDatabase = cachedData.map(pdf => prepareSearchIndex(pdf));
             // --- FIX: CALL THIS TO POPULATE UI ---
             syncClassSwitcher();
             renderSemesterTabs();
@@ -466,7 +497,9 @@ async function loadPDFDatabase() {
 
         pdfDatabase = [];
         snapshot.forEach(doc => {
-            pdfDatabase.push({ id: doc.id, ...doc.data() });
+            // ⚡ Bolt: Prepare search index immediately on fetch
+            let pdf = { id: doc.id, ...doc.data() };
+            pdfDatabase.push(prepareSearchIndex(pdf));
         });
 
         localStorage.setItem(CACHE_KEY, JSON.stringify({
@@ -901,27 +934,25 @@ function renderPDFs() {
     }
 
     // Locate renderPDFs() in script.js and update the filter section
+    // ⚡ Bolt: Fast-path filtering using early returns and pre-calculated index
     const filteredPdfs = pdfDatabase.filter(pdf => {
-        const matchesSemester = pdf.semester === currentSemester;
-
-        // NEW: Check if the PDF class matches the UI's current class selection
-        // Note: If old documents don't have this field, they will be hidden.
-        const matchesClass = pdf.class === currentClass;
+        // 1. Cheap Equality Checks First
+        if (pdf.class !== currentClass) return false;
+        if (pdf.semester !== currentSemester) return false;
 
-        let matchesCategory = false;
+        // 2. Category Check
         if (currentCategory === 'favorites') {
-            matchesCategory = favorites.includes(pdf.id);
-        } else {
-            matchesCategory = currentCategory === 'all' || pdf.category === currentCategory;
+            if (!favorites.includes(pdf.id)) return false;
+        } else if (currentCategory !== 'all') {
+            if (pdf.category !== currentCategory) return false;
         }
 
-        const matchesSearch = pdf.title.toLowerCase().includes(searchTerm) ||
-            pdf.description.toLowerCase().includes(searchTerm) ||
-            pdf.category.toLowerCase().includes(searchTerm) ||
-            pdf.author.toLowerCase().includes(searchTerm);
+        // 3. Expensive String Match Last (Using pre-calculated string)
+        if (searchTerm) {
+            return pdf._searchStr.includes(searchTerm);
+        }
 
-        // Update return statement to include matchesClass
-        return matchesSemester && matchesClass && matchesCategory && matchesSearch;
+        return true;
     });
 
     updatePDFCount(filteredPdfs.length);
@@ -991,9 +1022,8 @@ function createPDFCard(pdf, favoritesList, index = 0, highlightRegex = null) {
     const heartIconClass = isFav ? 'fas' : 'far';
     const btnActiveClass = isFav ? 'active' : '';
 
-    const uploadDateObj = new Date(pdf.uploadDate);
-    const timeDiff = new Date() - uploadDateObj;
-    const isNew = timeDiff < (7 * 24 * 60 * 60 * 1000); // 7 days
+    // ⚡ Bolt: Use pre-calculated values
+    const isNew = pdf._isNew;
 
     const newBadgeHTML = isNew
         ? `<span style="background:var(--error-color); color:white; font-size:0.6rem; padding:2px 6px; border-radius:4px; margin-left:8px; vertical-align:middle;">NEW</span>`
@@ -1008,7 +1038,8 @@ function createPDFCard(pdf, favoritesList, index = 0, highlightRegex = null) {
     const categoryIcon = categoryIcons[pdf.category] || 'fa-file-pdf';
 
     // Formatting Date
-    const formattedDate = new Date(pdf.uploadDate).toLocaleDateString('en-US', {
+    // ⚡ Bolt: Use pre-calculated date string
+    const formattedDate = pdf._formattedDate || new Date(pdf.uploadDate).toLocaleDateString('en-US', {
         year: 'numeric', month: 'short', day: 'numeric'
     });