Unnecessary and wasteful uses of std::map removed (performance optimization)

Author: VioletGiraffe

file-commander-core/src/cpanel.h

@@ -16,6 +16,8 @@ using FileSystemWatcher = CFileSystemWatcherWindows;
 using FileSystemWatcher = CFileSystemWatcherTimerBased;
 #endif
 
+#include <QHash>
+
 #include <mutex>
 #include <vector>
 #include <utility>
@@ -124,12 +126,20 @@ class CPanel final : public QObject
 		_uiThreadQueue.enqueue(std::forward<Functor>(f), tag);
 	}
 
+private:
+	struct QStringHash {
+		using is_avalanching = void;
+		[[nodiscard]] inline size_t operator()(const QString& s) const noexcept {
+			return qHash(s);
+		}
+	};
+
 private:
 	CFileSystemObject                          _currentDirObject;
 	FileSystemWatcher                          _watcher;
 	FileListHashMap                            _items;
 	CHistoryList<QString>                      _history;
-	std::map<QString, qulonglong /*hash*/>     _cursorPosForFolder;
+	ankerl::unordered_dense::map<QString, qulonglong /*hash*/, QStringHash> _cursorPosForFolder;
 	CallbackCaller<PanelContentsChangedListener> _panelContentsChangedListeners;
 	CallbackCaller<CursorPositionListener>    _currentItemChangeListener;
 	const Panel                                _panelPosition;

file-commander-core/src/detail/file_list_hashmap.h

@@ -7,7 +7,7 @@
 struct NullHash {
 	using is_avalanching = void;
 
-	qulonglong operator()(qulonglong hashValue) const noexcept {
+	[[nodiscard]] inline constexpr qulonglong operator()(qulonglong hashValue) const noexcept {
 		return hashValue;
 	}
 };

file-commander-core/src/fileoperations/coperationperformer.cpp

@@ -583,9 +583,9 @@ std::vector<QDir> COperationPerformer::enumerateSourcesAndCalcDest(uint64_t &tot
 
 UserResponse COperationPerformer::getUserResponse(HaltReason hr, const CFileSystemObject& src, const CFileSystemObject& dst, const QString& message)
 {
-	auto globalResponse = _globalResponses.find(hr);
-	if (globalResponse != _globalResponses.end())
-		return globalResponse->second;
+	const auto globalResponse = _globalResponses[hr];
+	if (globalResponse)
+		return globalResponse.value();
 
 	if (_observer) _observer->onProcessHaltedCallback(hr, src, dst, message);
 	waitForResponse();

file-commander-core/src/fileoperations/coperationperformer.h

@@ -4,10 +4,14 @@
 #include "cfilesystemobject.h"
 #include "system/ctimeelapsed.h"
 
+#include "3rdparty/magic_enum/magic_enum.hpp"
+
+#include <array>
 #include <atomic>
 #include <condition_variable>
 #include <functional>
 #include <mutex>
+#include <optional>
 #include <thread>
 #include <vector>
 
@@ -104,7 +108,8 @@ class COperationPerformer
 
 private:
 	std::vector<ObjectToProcess> _source;
-	std::map<HaltReason, UserResponse> _globalResponses;
+	// Essentially a map<HaltReason, UserResponse>
+	std::array<std::optional<UserResponse>, magic_enum::enum_count<HaltReason>()> _globalResponses;
 	CFileSystemObject              _destFileSystemObject;
 	QString                        _newName;
 	Operation                      _op;

file-commander-core/src/plugininterface/cpluginproxy.cpp

@@ -65,46 +65,30 @@ PanelPosition CPluginProxy::otherPanel() const
 PanelState& CPluginProxy::panelState(const PanelPosition panel)
 {
 	static PanelState empty;
-	if (panel == PluginUnknownPanel)
+	if (panel == PluginUnknownPanel) [[unlikely]]
 	{
 		assert_unconditional_r("Unknown panel");
 		empty = PanelState();
 		return empty;
 	}
 
-	const auto state = _panelState.find(panel);
-	if (state == _panelState.end())
-	{
-		assert_unconditional_r("Unknown panel");
-		empty = PanelState();
-		return empty;
-	}
-	else
-		return state->second;
+	return _panelState[panel];
 }
 
 const PanelState & CPluginProxy::panelState(const PanelPosition panel) const
 {
-	static const PanelState empty {};
-	if (panel == PluginUnknownPanel)
-	{
+	static const PanelState empty;
+	if (panel == PluginUnknownPanel) [[unlikely]]
 		return empty;
-	}
 
-	const auto state = _panelState.find(panel);
-	assert_and_return_r(state != _panelState.end(), empty);
-
-	return state->second;
+	return _panelState[panel];
 }
 
 QString CPluginProxy::currentFolderPathForPanel(const PanelPosition panel) const
 {
 	assert_and_return_r(panel != PluginUnknownPanel, QString());
 
-	const auto state = _panelState.find(panel);
-	assert_and_return_r(state != _panelState.end(), QString());
-
-	return state->second.currentFolder;
+	return _panelState[panel].currentFolder;
 }
 
 QString CPluginProxy::currentItemPathForPanel(const PanelPosition panel) const

file-commander-core/src/plugininterface/cpluginproxy.h

@@ -6,6 +6,7 @@ DISABLE_COMPILER_WARNINGS
 #include <QIcon>
 RESTORE_COMPILER_WARNINGS
 
+#include <array>
 #include <functional>
 #include <vector>
 
@@ -68,7 +69,7 @@ class CPluginProxy
 
 private:
 	CreateToolMenuEntryImplementationType _createToolMenuEntryImplementation;
-	std::map<PanelPosition, PanelState> _panelState;
+	std::array<PanelState, 2> _panelState;
 	std::function<void(std::function<void()>)> _execOnUiThreadImplementation;
 	PanelPosition                       _currentPanel = PluginUnknownPanel;
 };