Analyze and improve search in File Browser (again)

data/themes/classic/style.css

@@ -7,6 +7,11 @@ QLabel, QTreeWidget, QListWidget, QGroupBox, QMenuBar {
 	color: #e0e0e0;
 }
 
+QProgressBar::chunk {
+	background-color: #e0e0e0;
+	border-radius: 5px;
+}
+
 QMdiArea {
 	background-image: url("resources:background_artwork.png");
 }

data/themes/default/style.css

@@ -7,6 +7,11 @@ QLabel, QTreeWidget, QListWidget, QGroupBox, QMenuBar, QCheckBox {
 	color: #d1d8e4;
 }
 
+QProgressBar::chunk {
+	background-color: #d1d8e4;
+	border-radius: 5px;
+}
+
 QTreeView {
 	outline: none;
 	alternate-background-color: #111314;

include/FileBrowser.h

@@ -29,15 +29,8 @@
 #include <QDir>
 #include <QMutex>
 
-#ifdef __MINGW32__
-#include <mingw.condition_variable.h>
-#include <mingw.mutex.h>
-#include <mingw.thread.h>
-#else
-#include <condition_variable>
-#include <mutex>
-#include <thread>
-#endif
+#include "FileBrowserSearcher.h"
+#include <QProgressBar>
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5,14,0))
 	#include <QRecursiveMutex>
@@ -83,12 +76,12 @@ class FileBrowser : public SideBarWidget
 
 	~FileBrowser() override = default;
 
-	static QDir::Filters dirFilters();
+	static QDir::Filters dirFilters() { return QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot; }
+	static QDir::SortFlags sortFlags() { return QDir::LocaleAware | QDir::DirsFirst | QDir::Name | QDir::IgnoreCase; }
 
 private slots:
 	void reloadTree();
 	void expandItems( QTreeWidgetItem * item=nullptr, QList<QString> expandedDirs = QList<QString>() );
-	bool filterAndExpandItems(const QString & filter, QTreeWidgetItem * item = nullptr);
 	void giveFocusToFilter();
 
 private:
@@ -99,7 +92,7 @@ private slots:
 	void saveDirectoriesStates();
 	void restoreDirectoriesStates();
 
-	void buildSearchTree(QStringList matches, QString id);
+	void buildSearchTree();
 	void onSearch(const QString& filter);
 	void toggleSearch(bool on);
 
@@ -108,6 +101,9 @@ private slots:
 
 	QLineEdit * m_filterEdit;
 
+	std::shared_ptr<FileBrowserSearcher::SearchFuture> m_currentSearch;
+	QProgressBar* m_searchIndicator = nullptr;
+
 	QString m_directories; //!< Directories to search, split with '*'
 	QString m_filter; //!< Filter as used in QDir::match()
 
@@ -183,54 +179,12 @@ private slots:
 
 } ;
 
-class FileBrowserSearcher : public QObject
-{
-	Q_OBJECT
-public:
-	struct SearchTask
-	{
-		QString directories;
-		QString userFilter;
-		QDir::Filters dirFilters;
-		QStringList nameFilters;
-		QString id;
-	};
-
-	FileBrowserSearcher();
-	~FileBrowserSearcher() noexcept override;
-
-	void search(SearchTask task);
-	void cancel();
-
-	bool inHiddenDirectory(const QString& path);
-
-	static FileBrowserSearcher* instance();
-
-signals:
-	void searchComplete(QStringList matches, QString id);
-
-private:
-	void run();
-	void filter();
-	SearchTask m_currentTask;
-	std::thread m_worker;
-	std::mutex m_runMutex;
-	std::mutex m_cancelMutex;
-	std::condition_variable m_runCond;
-	std::atomic<bool> m_cancel = false;
-	bool m_stopped = false;
-	bool m_run = false;
-	inline static std::unique_ptr<FileBrowserSearcher> s_instance = nullptr;
-};
-
-
 
 
 class Directory : public QTreeWidgetItem
 {
 public:
-	Directory( const QString & filename, const QString & path,
-						const QString & filter );
+	Directory(const QString& filename, const QString& path, const QString& filter, bool disableEntryPopulation = false);
 
 	void update();
 
@@ -275,7 +229,7 @@ class Directory : public QTreeWidgetItem
 	QString m_filter;
 
 	int m_dirCount;
-
+	bool m_disableEntryPopulation = false;
 } ;
 
 

include/FileBrowserSearcher.h

@@ -0,0 +1,134 @@
+/*
+ * FileBrowserSearcher.h - Batch processor for searching the filesystem
+ *
+ * Copyright (c) 2023 saker <[email protected]>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LMMS_FILE_BROWSER_SEARCHER_H
+#define LMMS_FILE_BROWSER_SEARCHER_H
+
+#include <QHash>
+#include <QString>
+#include <QStringList>
+#include <optional>
+#include <queue>
+
+#ifdef __MINGW32__
+#include <mingw.condition_variable.h>
+#include <mingw.mutex.h>
+#include <mingw.thread.h>
+#else
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+#endif
+
+namespace lmms::gui {
+class FileBrowserSearcher
+{
+public:
+	static constexpr int s_batchSize = 16;
+	static constexpr int s_millisecondsPerBatch = 500;
+
+	//! The future that will be returned to the requester, as well as read and modified by both the requester and
+	//! worker thread. Acessing the filter, paths to search, and valid file extensions can be done concurrently since
+	//! they do not change after construction. Access to the batch queue is protected under a mutex, while the state
+	//! variable is atomic.
+	class SearchFuture
+	{
+	public:
+		//! The state for this future. The state of this object can be read/written atomically. In a cancelled
+		//! state, the requester doesn't need to continue using this future and can abort any operations made using it.
+		//! Once in a completed or cancelled state, the worker thread no longer has shared ownership of this future
+		//! (i.e., all ownership will go to the requester).
+		enum class State
+		{
+			Idle,
+			Running,
+			Cancelled,
+			Completed
+		};
+
+		SearchFuture(const QString& filter, const QStringList& paths, const QStringList& extensions)
+			: m_filter(filter)
+			, m_paths(paths)
+			, m_extensions(extensions)
+		{
+		}
+
+		//! Read the current state of the future object. This function can run concurrently with the worker thread.
+		auto state() -> State { return m_state; }
+
+		//! Read a batch of search results. This function can run concurrently with the worker thread. Returns a empty
+		//! list if no batches are available.
+		auto batch() -> QStringList;
+
+		auto filter() -> const QString& { return m_filter; }
+		auto paths() -> const QStringList& { return m_paths; }
+		auto extensions() -> const QStringList& { return m_extensions; }
+
+	private:
+		auto addBatch(QStringList& matches) -> void;
+
+		QString m_filter;
+		QStringList m_paths;
+		QStringList m_extensions;
+
+		std::list<QStringList> m_batchQueue;
+		std::mutex m_batchQueueMutex;
+
+		std::atomic<State> m_state = State::Idle;
+
+		friend FileBrowserSearcher;
+	};
+
+	~FileBrowserSearcher();
+
+	//! Enqueues a search to be ran by the worker thread.
+	//! Returns a future that the caller can use to track state and results of the operation.
+	auto search(const QString& filter, const QStringList& paths, const QStringList& extensions)
+		-> std::shared_ptr<SearchFuture>;
+
+	//! Sends a signal to cancel a running search.
+	auto cancel() -> void { m_cancelRunningSearch = true; }
+
+	//! Returns the global instance of the searcher object.
+	static auto instance() -> FileBrowserSearcher*
+	{
+		static auto s_instance = FileBrowserSearcher{};
+		return &s_instance;
+	}
+
+private:
+	auto run() -> void;
+	auto process(std::shared_ptr<SearchFuture> searchFuture) -> void;
+
+	std::queue<std::shared_ptr<SearchFuture>> m_searchQueue;
+	std::atomic<bool> m_cancelRunningSearch = false;
+
+	bool m_workerStopped = false;
+	std::mutex m_workerMutex;
+	std::condition_variable m_workerCond;
+	std::thread m_worker{[this] { run(); }};
+};
+} // namespace lmms::gui
+
+#endif // LMMS_FILE_BROWSER_SEARCHER_H

src/gui/CMakeLists.txt

@@ -14,6 +14,7 @@ SET(LMMS_SRCS
 	gui/EffectView.cpp
 	gui/embed.cpp
 	gui/FileBrowser.cpp
+	gui/FileBrowserSearcher.cpp
 	gui/GuiApplication.cpp
 	gui/LadspaControlView.cpp
 	gui/LfoControllerDialog.cpp