Redesign file browser searching (LMMS#7130)

include/FileBrowser.h

@@ -28,10 +28,11 @@
 #include <QCheckBox>
 #include <QDir>
 #include <QMutex>
-#include "embed.h"
-
-#include "FileBrowserSearcher.h"
 #include <QProgressBar>
+#include <memory>
+
+#include "FileSearch.h"
+#include "embed.h"
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5,14,0))
 	#include <QRecursiveMutex>
@@ -76,9 +77,9 @@ class FileBrowser : public SideBarWidget
 
 	~FileBrowser() override = default;
 
-	static QStringList directoryBlacklist()
+	static QStringList excludedPaths()
 	{
-		static auto s_blacklist = QStringList{
+		static auto s_excludedPaths = QStringList{
 #ifdef LMMS_BUILD_LINUX
 			"/bin", "/boot", "/dev", "/etc", "/proc", "/run", "/sbin",
 			"/sys"
@@ -87,7 +88,7 @@ class FileBrowser : public SideBarWidget
 			"C:\\Windows"
 #endif
 		};
-		return s_blacklist;
+		return s_excludedPaths;
 	}
 	static QDir::Filters dirFilters() { return QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot; }
 	static QDir::SortFlags sortFlags() { return QDir::LocaleAware | QDir::DirsFirst | QDir::Name | QDir::IgnoreCase; }
@@ -105,16 +106,17 @@ private slots:
 	void saveDirectoriesStates();
 	void restoreDirectoriesStates();
 
-	void buildSearchTree();
+	void foundSearchMatch(FileSearch* search, const QString& match);
+	void searchCompleted(FileSearch* search);
 	void onSearch(const QString& filter);
-	void toggleSearch(bool on);
+	void displaySearch(bool on);
 
 	FileBrowserTreeWidget * m_fileBrowserTreeWidget;
 	FileBrowserTreeWidget * m_searchTreeWidget;
 
 	QLineEdit * m_filterEdit;
 
-	std::shared_ptr<FileBrowserSearcher::SearchFuture> m_currentSearch;
+	std::shared_ptr<FileSearch> m_currentSearch;
 	QProgressBar* m_searchIndicator = nullptr;
 
 	QString m_directories; //!< Directories to search, split with '*'

include/FileSearch.h

@@ -0,0 +1,73 @@
+/*
+ * FileSearch.h - File system search task
+ *
+ * Copyright (c) 2024 saker
+ *
+ * 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_SEARCH_H
+#define LMMS_FILE_SEARCH_H
+
+#include <QDir>
+#include <QObject>
+#include <atomic>
+
+namespace lmms {
+//! A Qt object that encapsulates the operation of searching the file system.
+class FileSearch : public QObject
+{
+	Q_OBJECT
+public:
+	//! Number of milliseconds the search waits before signaling a matching result.
+	static constexpr int MillisecondsBetweenResults = 1;
+
+	//! Create a `FileSearch` object that uses the specified string filter `filter` and extension filters in
+	//! `extensions` to search within the given `paths`.
+	//! `excludedPaths`, `dirFilters`, and `sortFlags` can optionally be specified to exclude certain directories, filter
+	//! out certain types of entries, and sort the matches.
+	FileSearch(const QString& filter, const QStringList& paths, const QStringList& extensions,
+		const QStringList& excludedPaths = {}, QDir::Filters dirFilters = QDir::Filters{},
+		QDir::SortFlags sortFlags = QDir::SortFlags{});
+
+	//! Execute the search, emitting the `foundResult` signal when matches are found.
+	void operator()();
+
+	//! Cancel the search.
+	void cancel();
+
+signals:
+	//! Emitted when a result is found when searching the file system.
+	void foundMatch(FileSearch* search, const QString& match);
+
+	//! Emitted when the search completes.
+	void searchCompleted(FileSearch* search);
+
+private:
+	static auto isPathExcluded(const QString& path) -> bool;
+	QString m_filter;
+	QStringList m_paths;
+	QStringList m_extensions;
+	QStringList m_excludedPaths;
+	QDir::Filters m_dirFilters;
+	QDir::SortFlags m_sortFlags;
+	std::atomic<bool> m_cancel = false;
+};
+} // namespace lmms
+#endif // LMMS_FILE_SEARCH_H

include/ThreadPool.h

@@ -0,0 +1,100 @@
+/*
+ * ThreadPool.h
+ *
+ * Copyright (c) 2024 saker
+ *
+ * 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_THREAD_POOL_H
+#define LMMS_THREAD_POOL_H
+
+#include <atomic>
+#include <queue>
+#include <tuple>
+#include <type_traits>
+#include <vector>
+
+#ifdef __MINGW32__
+#include <mingw.condition_variable.h>
+#include <mingw.future.h>
+#include <mingw.mutex.h>
+#include <mingw.thread.h>
+#else
+#include <condition_variable>
+#include <future>
+#include <mutex>
+#include <thread>
+#endif
+
+namespace lmms {
+//! A thread pool that can be used for asynchronous processing.
+class ThreadPool
+{
+public:
+	//! Destroys the `ThreadPool` object.
+	//! This blocks until all workers have finished executing.
+	~ThreadPool();
+
+	//! Enqueue function `fn` with arguments `args` to be ran asynchronously.
+	template <typename Fn, typename... Args>
+	auto enqueue(Fn&& fn, Args&&... args) -> std::future<std::invoke_result_t<Fn, Args...>>
+	{
+		using ReturnType = std::invoke_result_t<Fn, Args...>;
+
+		auto promise = std::make_shared<std::promise<ReturnType>>();
+		auto task = [promise, fn = std::forward<Fn>(fn), args = std::make_tuple(std::forward<Args>(args)...)] 
+		{
+			if constexpr (!std::is_same_v<ReturnType, void>)
+			{
+				promise->set_value(std::apply(fn, args));
+				return;
+			}
+			std::apply(fn, args);
+			promise->set_value();
+		};
+
+		{
+			const auto lock = std::unique_lock{m_runMutex};
+			m_queue.push(std::move(task));
+		}
+
+		m_runCond.notify_one();
+		return promise->get_future();
+	}
+
+	//! Return the number of worker threads used.
+	auto numWorkers() const -> size_t;
+
+	//! Return the global `ThreadPool` instance.
+	static auto instance() -> ThreadPool&;
+
+private:
+	ThreadPool(size_t numWorkers);
+	void run();
+	std::vector<std::thread> m_workers;
+	std::queue<std::function<void()>> m_queue;
+	std::atomic<bool> m_done = false;
+	std::condition_variable m_runCond;
+	std::mutex m_runMutex;
+	inline static size_t s_numWorkers = std::thread::hardware_concurrency();
+};
+} // namespace lmms
+
+#endif // LMMS_THREAD_POOL_H

src/core/CMakeLists.txt

@@ -23,6 +23,7 @@ set(LMMS_SRCS
 	core/Engine.cpp
 	core/EnvelopeAndLfoParameters.cpp
 	core/fft_helpers.cpp
+	core/FileSearch.cpp
 	core/Mixer.cpp
 	core/ImportFilter.cpp
 	core/InlineAutomation.cpp
@@ -76,6 +77,7 @@ set(LMMS_SRCS
 	core/SerializingObject.cpp
 	core/Song.cpp
 	core/TempoSyncKnobModel.cpp
+	core/ThreadPool.cpp
 	core/Timeline.cpp
 	core/TimePos.cpp
 	core/ToolPlugin.cpp