Speed up search index loading

src/front-end/searcher/searcher.js

@@ -3,7 +3,7 @@
 /* global Mark, elasticlunr, path_to_root */
 
 window.search = window.search || {};
-(function search(search) {
+(function search() {
     // Search functionality
     //
     // You can use !hasFocus() to prevent keyhandling in your key
@@ -288,6 +288,9 @@ window.search = window.search || {};
 
         // If reloaded, do the search or mark again, depending on the current url parameters
         doSearchOrMarkFromUrl();
+
+        // Exported functions
+        config.hasFocus = hasFocus;
     }
 
     function unfocusSearchbar() {
@@ -521,6 +524,4 @@ window.search = window.search || {};
 
     loadScript(path_to_root + '{{ resource "searchindex.js" }}', 'search-index');
 
-    // Exported functions
-    search.hasFocus = hasFocus;
 })(window.search);

src/renderer/html_handlebars/search.rs

@@ -66,7 +66,13 @@ pub fn create_files(
     if search_config.copy_js {
         static_files.add_builtin(
             "searchindex.js",
-            format!("Object.assign(window.search, {});", index).as_bytes(),
+            // To reduce the size of the generated JSON by preventing all `"` characters to be
+            // escaped, we instead surround the string with much less common `'` character.
+            format!(
+                "window.search = JSON.parse('{}');",
+                index.replace("\\", "\\\\").replace("'", "\\'")
+            )
+            .as_bytes(),
         );
         static_files.add_builtin("searcher.js", searcher::JS);
         static_files.add_builtin("mark.min.js", searcher::MARK_JS);

tests/rendered_output.rs

@@ -773,9 +773,10 @@ mod search {
     fn read_book_index(root: &Path) -> serde_json::Value {
         let index = root.join("book/searchindex.js");
         let index = fs::read_to_string(index).unwrap();
-        let index = index.trim_start_matches("Object.assign(window.search, ");
-        let index = index.trim_end_matches(");");
-        serde_json::from_str(index).unwrap()
+        let index = index.trim_start_matches("window.search = JSON.parse('");
+        let index = index.trim_end_matches("');");
+        // We need unescape the string as it's supposed to be an escaped JS string.
+        serde_json::from_str(&index.replace("\\'", "'").replace("\\\\", "\\")).unwrap()
     }
 
     #[test]