Improve local filetree view state and sidebar performance

rust/crates/mnote-web/src/routes/local_search_index.rs

@@ -56,7 +56,7 @@ pub(crate) fn query_local_search_index(
     title_only: bool,
     exact: bool,
 ) -> Result<Value, WebError> {
-    let index = rebuild_local_search_index(root_path, root_uri, workspace_id)?;
+    let index = load_or_rebuild_local_search_index(root_path, root_uri, workspace_id)?;
     let normalized_query = normalize_search_text(query);
     let page_id = page_id.map(str::trim).filter(|value| !value.is_empty());
     let recent_changes = local_recent_changes_projection(&index.documents, root_uri);
@@ -294,6 +294,23 @@ fn rebuild_local_search_index(
     Ok(index)
 }
 
+fn load_or_rebuild_local_search_index(
+    root_path: &Path,
+    root_uri: &str,
+    workspace_id: &str,
+) -> Result<LocalSearchIndex, WebError> {
+    match read_local_search_index(root_path) {
+        Ok(Some(index))
+            if index.version == LOCAL_SEARCH_INDEX_VERSION
+                && index.root_uri == root_uri
+                && index.workspace_id == workspace_id =>
+        {
+            Ok(index)
+        }
+        Ok(_) | Err(_) => rebuild_local_search_index(root_path, root_uri, workspace_id),
+    }
+}
+
 fn read_local_search_index(root_path: &Path) -> Result<Option<LocalSearchIndex>, WebError> {
     let index_path = root_path
         .join(".mnote")
@@ -999,4 +1016,74 @@ mod tests {
             .any(|document| document.path == "README.md"));
         let _ = fs::remove_dir_all(&root);
     }
+
+    #[test]
+    fn local_search_query_reads_existing_index_without_rebuilding() {
+        let root = temp_root("mnote-local-search-query-cache");
+        let root_uri = format!("file://{}", root.display());
+        let workspace_id = "local-ws-query-cache";
+        let child_path = root.join("docs").join("child.md");
+        fs::write(
+            &child_path,
+            "---\ntitle: Child\n---\n# Child\nOriginalToken body.\n",
+        )
+        .expect("write child");
+
+        let first_projection = query_local_search_index(
+            &root,
+            &root_uri,
+            workspace_id,
+            "OriginalToken",
+            None,
+            10,
+            false,
+            false,
+        )
+        .expect("first query");
+        assert_eq!(
+            first_projection["results"].as_array().map(Vec::len),
+            Some(1)
+        );
+
+        fs::write(
+            &child_path,
+            "---\ntitle: Child\n---\n# Child\nUnindexedToken body.\n",
+        )
+        .expect("update child without refresh");
+
+        let stale_projection = query_local_search_index(
+            &root,
+            &root_uri,
+            workspace_id,
+            "UnindexedToken",
+            None,
+            10,
+            false,
+            false,
+        )
+        .expect("query existing index");
+        assert_eq!(
+            stale_projection["results"].as_array().map(Vec::len),
+            Some(0)
+        );
+
+        refresh_local_search_index_for_path(&root, &root_uri, workspace_id, "docs/child.md")
+            .expect("incremental refresh");
+        let refreshed_projection = query_local_search_index(
+            &root,
+            &root_uri,
+            workspace_id,
+            "UnindexedToken",
+            None,
+            10,
+            false,
+            false,
+        )
+        .expect("query refreshed index");
+        assert_eq!(
+            refreshed_projection["results"].as_array().map(Vec::len),
+            Some(1)
+        );
+        let _ = fs::remove_dir_all(&root);
+    }
 }