Make searching more responsive on large libraries (Jamendo)

src/library/libraryfilterwidget.cpp

@@ -23,20 +23,26 @@
 #include "ui/settingsdialog.h"
 #include "widgets/maclineedit.h"
 
+#include <QActionGroup>
 #include <QKeyEvent>
 #include <QMenu>
-#include <QActionGroup>
-#include <QSignalMapper>
 #include <QSettings>
+#include <QSignalMapper>
+#include <QTimer>
 
 LibraryFilterWidget::LibraryFilterWidget(QWidget *parent)
   : QWidget(parent),
     ui_(new Ui_LibraryFilterWidget),
     model_(NULL),
-    group_by_dialog_(new GroupByDialog)
+    group_by_dialog_(new GroupByDialog),
+    filter_delay_(new QTimer(this))
 {
   ui_->setupUi(this);
   connect(ui_->filter, SIGNAL(returnPressed()), SIGNAL(ReturnPressed()));
+  connect(filter_delay_, SIGNAL(timeout()), SLOT(FilterDelayTimeout()));
+
+  filter_delay_->setInterval(kFilterDelay);
+  filter_delay_->setSingleShot(true);
 
   // Icons
   ui_->clear->setIcon(IconLoader::Load("edit-clear-locationbar-ltr"));
@@ -114,6 +120,8 @@ LibraryFilterWidget::LibraryFilterWidget(QWidget *parent)
 #else
   filter_ = ui_->filter;
 #endif
+
+  connect(filter_->object(), SIGNAL(textChanged(QString)), SLOT(FilterTextChanged(QString)));
 }
 
 LibraryFilterWidget::~LibraryFilterWidget() {
@@ -125,7 +133,6 @@ void LibraryFilterWidget::SetLibraryModel(LibraryModel *model) {
     disconnect(model_, 0, this, 0);
     disconnect(model_, 0, group_by_dialog_.get(), 0);
     disconnect(group_by_dialog_.get(), 0, model_, 0);
-    disconnect(filter_->object(), 0, model_, 0);
     disconnect(filter_age_mapper_, 0, model_, 0);
   }
 
@@ -138,7 +145,6 @@ void LibraryFilterWidget::SetLibraryModel(LibraryModel *model) {
           SLOT(GroupingChanged(LibraryModel::Grouping)));
   connect(group_by_dialog_.get(), SIGNAL(Accepted(LibraryModel::Grouping)),
           model_, SLOT(SetGroupBy(LibraryModel::Grouping)));
-  connect(filter_->object(), SIGNAL(textChanged(QString)), model_, SLOT(SetFilterText(QString)));
   connect(filter_age_mapper_, SIGNAL(mapped(int)), model_, SLOT(SetFilterAge(int)));
 
   // Load settings
@@ -226,3 +232,20 @@ void LibraryFilterWidget::keyReleaseEvent(QKeyEvent* e) {
 
   QWidget::keyReleaseEvent(e);
 }
+
+void LibraryFilterWidget::FilterTextChanged(const QString& text) {
+  // Searching with one or two characters can be very expensive on the database
+  // even with FTS, so if there are a large number of songs in the database
+  // introduce a small delay before actually filtering the model, so if the
+  // user is typing the first few characters of something it will be quicker.
+  if (!text.isEmpty() && text.length() < 3 && model_->total_song_count() >= 100000) {
+    filter_delay_->start();
+  } else {
+    filter_delay_->stop();
+    model_->SetFilterText(text);
+  }
+}
+
+void LibraryFilterWidget::FilterDelayTimeout() {
+  model_->SetFilterText(filter_->text());
+}

src/library/libraryfilterwidget.h

@@ -40,6 +40,8 @@ class LibraryFilterWidget : public QWidget {
   LibraryFilterWidget(QWidget* parent = 0);
   ~LibraryFilterWidget();
 
+  static const int kFilterDelay = 500; // msec
+
   void SetFilterHint(const QString& hint);
   void SetAgeFilterEnabled(bool enabled);
   void SetGroupByEnabled(bool enabled);
@@ -64,6 +66,9 @@ class LibraryFilterWidget : public QWidget {
   void GroupByClicked(QAction* action);
   void ClearFilter();
 
+  void FilterTextChanged(const QString& text);
+  void FilterDelayTimeout();
+
  private:
   Ui_LibraryFilterWidget* ui_;
   LibraryModel* model_;
@@ -77,6 +82,8 @@ class LibraryFilterWidget : public QWidget {
   QActionGroup* group_by_group_;
   QSignalMapper* filter_age_mapper_;
 
+  QTimer* filter_delay_;
+
   QString settings_group_;
 
   LineEditInterface* filter_;

src/library/librarymodel.cpp

@@ -55,6 +55,7 @@ LibraryModel::LibraryModel(LibraryBackend* backend, QObject* parent)
     dir_model_(new LibraryDirectoryModel(backend, this)),
     show_smart_playlists_(false),
     show_various_artists_(true),
+    total_song_count_(0),
     artist_icon_(":/icons/22x22/x-clementine-artist.png"),
     album_icon_(":/icons/22x22/x-clementine-album.png"),
     no_cover_icon_(":nocover.png"),
@@ -77,7 +78,7 @@ void LibraryModel::Init() {
   connect(backend_, SIGNAL(SongsDeleted(SongList)), SLOT(SongsDeleted(SongList)));
   connect(backend_, SIGNAL(SongsStatisticsChanged(SongList)), SLOT(SongsStatisticsChanged(SongList)));
   connect(backend_, SIGNAL(DatabaseReset()), SLOT(Reset()));
-  connect(backend_, SIGNAL(TotalSongCountUpdated(int)), SIGNAL(TotalSongCountUpdated(int)));
+  connect(backend_, SIGNAL(TotalSongCountUpdated(int)), SLOT(TotalSongCountUpdatedSlot(int)));
 
   backend_->UpdateTotalSongCountAsync();
 
@@ -1107,3 +1108,8 @@ GeneratorPtr LibraryModel::CreateGenerator(const QModelIndex& index) const {
   ret->Load(item->smart_playlist_data);
   return ret;
 }
+
+void LibraryModel::TotalSongCountUpdatedSlot(int count) {
+  total_song_count_ = count;
+  emit TotalSongCountUpdated(count);
+}

src/library/librarymodel.h

@@ -112,6 +112,9 @@ class LibraryModel : public SimpleTreeModel<LibraryItem> {
   SongList GetChildSongs(const QModelIndex& index) const;
   SongList GetChildSongs(const QModelIndexList& indexes) const;
 
+  // Might be accurate
+  int total_song_count() const { return total_song_count_; }
+
   // Smart playlists
   smart_playlists::GeneratorPtr CreateGenerator(const QModelIndex& index) const;
   void AddGenerator(smart_playlists::GeneratorPtr gen);
@@ -146,6 +149,7 @@ class LibraryModel : public SimpleTreeModel<LibraryItem> {
   void SongsDiscovered(const SongList& songs);
   void SongsDeleted(const SongList& songs);
   void SongsStatisticsChanged(const SongList& songs);
+  void TotalSongCountUpdatedSlot(int count);
 
   // Called after ResetAsync
   void ResetAsyncQueryFinished();
@@ -215,6 +219,8 @@ class LibraryModel : public SimpleTreeModel<LibraryItem> {
   DefaultGenerators default_smart_playlists_;
   bool show_various_artists_;
 
+  int total_song_count_;
+
   QueryOptions query_options_;
   Grouping group_by_;