#3587 note: try to prevent typing lag on slow network shared, by improving backlink scans

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - Added an optional editor setting to show character, word and line counts in the
   status bar (for [#536](https://github.com/pbek/QOwnNotes/issues/536))
+- Try to fix typing lag with Notes on a network share by avoiding repeated backlink
+  scans while typing when the backlink inputs did not change, and by computing
+  backlink-relative note paths without touching every note file on disk
+  (for [#3587](https://github.com/pbek/QOwnNotes/issues/3587))
 
 ## 26.6.3
 

src/entities/note.cpp

@@ -2768,12 +2768,18 @@ QString Note::getFullFilePathForFile(const QString &fileName) {
     return canonicalFilePath;
 }
 
-QString Note::getFilePathRelativeToNote(const Note &note, const QString &connectionName) const {
-    const QDir dir(fullNoteFilePath(connectionName));
+QString Note::getFilePathRelativeToNote(const Note &note, const QString &connectionName,
+                                        bool resolveFileSystemPaths) const {
+    const QDir dir(resolveFileSystemPaths
+                       ? fullNoteFilePath(connectionName)
+                       : relativeNoteFilePath(QStringLiteral("/"), connectionName));
 
     // for some reason there is a leading "../" too much
     static const QRegularExpression re(QStringLiteral(R"(^\.\.\/)"));
-    QString path = dir.relativeFilePath(note.fullNoteFilePath(connectionName)).remove(re);
+    const QString notePath = resolveFileSystemPaths
+                                 ? note.fullNoteFilePath(connectionName)
+                                 : note.relativeNoteFilePath(QStringLiteral("/"), connectionName);
+    QString path = dir.relativeFilePath(notePath).remove(re);
 
     // if "note" is the current note we want to use the real filename
     if (path == QChar('.')) {
@@ -4737,7 +4743,8 @@ QVector<int> Note::findBacklinkedNoteIds(const QString &connectionName) const {
             continue;
         }
 
-        const QString relativePathToNote = note.getFilePathRelativeToNote(*this, connectionName);
+        const QString relativePathToNote =
+            note.getFilePathRelativeToNote(*this, connectionName, false);
 
         // We now don't escape slashes in the relative file path, but previously we did,
         // so we need to search for both
@@ -5054,7 +5061,8 @@ QHash<Note, QSet<LinkHit>> Note::findReverseLinkNotes(const QString &connectionN
             continue;
         }
 
-        const QString relativePathToNote = note.getFilePathRelativeToNote(*this, connectionName);
+        const QString relativePathToNote =
+            note.getFilePathRelativeToNote(*this, connectionName, false);
 
         // Search legacy note:// protocol links
         addTextToBacklinkNoteHashIfFound(note, QStringLiteral("<") + noteUrl + QStringLiteral(">"));

src/entities/note.h

@@ -134,8 +134,9 @@ class Note {
 
     static QString getFullFilePathForFile(const QString &fileName);
 
-    QString getFilePathRelativeToNote(
-        const Note &note, const QString &connectionName = QStringLiteral("memory")) const;
+    QString getFilePathRelativeToNote(const Note &note,
+                                      const QString &connectionName = QStringLiteral("memory"),
+                                      bool resolveFileSystemPaths = true) const;
 
     static int storeDirtyNotesToDisk(Note &currentNote, bool *currentNoteChanged = nullptr,
                                      bool *noteWasRenamed = nullptr,

src/managers/navigationmanager.cpp

@@ -30,6 +30,8 @@
 #include <QRegularExpression>
 #include <QScrollBar>
 #include <QSqlDatabase>
+#include <QSqlQuery>
+#include <QStringList>
 #include <QTabWidget>
 #include <QTextCursor>
 #include <QUrl>
@@ -108,6 +110,14 @@ void NavigationManager::updateFileNavigationTab() {
 
 void NavigationManager::updateBacklinkNavigationTab() {
     const Note note = _mainWindow->currentNote;
+    const QString cacheKey = backlinkNavigationCacheKey();
+    const bool backlinkTabVisible = _ui->navigationTabWidget->indexOf(_ui->backlinkTab) >= 0;
+    if (!backlinkTabVisible && !_lastBacklinkNavigationCacheKey.isEmpty() &&
+        (_lastBacklinkNavigationCacheKey == cacheKey)) {
+        return;
+    }
+
+    _lastBacklinkNavigationCacheKey = cacheKey;
     Note noteCopy(note);
     const quint64 requestId = ++_mainWindow->_backlinkNavigationUpdateRequestId;
     QPointer<MainWindow> window(_mainWindow);
@@ -151,6 +161,29 @@ void NavigationManager::updateBacklinkNavigationTab() {
     Q_UNUSED(future)
 }
 
+QString NavigationManager::backlinkNavigationCacheKey() const {
+    const Note note = _mainWindow->currentNote;
+    QStringList keyParts{QString::number(note.getId()), QString::number(note.getNoteSubFolderId()),
+                         note.getFileName(), note.getName()};
+
+    const QSqlDatabase db = QSqlDatabase::database(QStringLiteral("memory"), false);
+    if (!db.isValid() || !db.isOpen()) {
+        return keyParts.join(QLatin1Char('|'));
+    }
+
+    QSqlQuery query(db);
+    query.prepare(QStringLiteral(
+        "SELECT COUNT(*), MAX(modified), MAX(file_last_modified) FROM note WHERE id != :id"));
+    query.bindValue(QStringLiteral(":id"), note.getId());
+
+    if (query.exec() && query.first()) {
+        keyParts << query.value(0).toString() << query.value(1).toString()
+                 << query.value(2).toString();
+    }
+
+    return keyParts.join(QLatin1Char('|'));
+}
+
 void NavigationManager::selectNavigationItemAtPosition(int position) {
     if (_ui->navigationWidget->isVisible()) {
         _ui->navigationWidget->selectItemForCursorPosition(position);

src/managers/navigationmanager.h

@@ -51,10 +51,12 @@ class NavigationManager : public QObject {
     void on_actionJump_to_navigation_panel_triggered();
 
    private:
+    QString backlinkNavigationCacheKey() const;
     void updateNoteTextStatistics(QOwnNotesMarkdownTextEdit *textEdit);
 
     MainWindow *_mainWindow;
     Ui::MainWindow *_ui;
+    QString _lastBacklinkNavigationCacheKey;
     QOwnNotesMarkdownTextEdit *_lastStatisticsTextEdit = nullptr;
     int _lastStatisticsNoteId = 0;
     int _lastStatisticsRevision = -1;