Only watch the desktop folders

- Create less fs watchers
- Just re-scan when a directory containing .desktop files changes

Author: bbedward

src/core/desktopentry.cpp

@@ -384,67 +384,33 @@ DesktopEntry* DesktopEntryManager::byId(const QString& id) {
 ObjectModel<DesktopEntry>* DesktopEntryManager::applications() { return &this->mApplications; }
 
 void DesktopEntryManager::handleFileChanges(
-    const QHash<QString, DesktopEntryMonitor::ChangeEvent>& changes
+    const QHash<QString, DesktopEntryMonitor::ChangeEvent>&
 ) {
+	qCDebug(logDesktopEntry) << "Directory change detected, performing full rescan";
 
-	qCDebug(logDesktopEntry) << "Handling file changes:" << changes.size() << "changes";
-
-	bool needsUpdate = false;
-
-	for (auto it = changes.begin(); it != changes.end(); ++it) {
-		const QString& path = it.key();
-		DesktopEntryMonitor::ChangeEvent event = it.value();
-
-		switch (event) {
-		case DesktopEntryMonitor::ChangeEvent::Added:
-		case DesktopEntryMonitor::ChangeEvent::Modified: {
-			// Parse the desktop file
-			QFile file(path);
-			if (file.open(QFile::ReadOnly)) {
-				QString id = this->extractIdFromPath(path);
-				auto* entry = new DesktopEntry(id, this);
-				entry->parseEntry(QString::fromUtf8(file.readAll()));
-
-				if (entry->isValid()) {
-					// Remove old entry if exists
-					if (this->desktopEntries.contains(id)) {
-						auto* oldEntry = this->desktopEntries.value(id);
-						this->desktopEntries.remove(id);
-						this->lowercaseDesktopEntries.remove(id.toLower());
-						oldEntry->deleteLater();
-					}
-
-					this->desktopEntries.insert(id, entry);
-					this->lowercaseDesktopEntries.insert(id.toLower(), entry);
-					needsUpdate = true;
-
-					qCDebug(logDesktopEntry) << "Updated desktop entry:" << id;
-				} else {
-					delete entry;
-				}
-			}
-			break;
-		}
+	auto oldEntries = this->desktopEntries;
 
-		case DesktopEntryMonitor::ChangeEvent::Removed: {
-			QString id = this->extractIdFromPath(path);
-			if (this->desktopEntries.contains(id)) {
-				auto* entry = this->desktopEntries.take(id);
-				this->lowercaseDesktopEntries.remove(id.toLower());
-				entry->deleteLater();
-				needsUpdate = true;
+	this->desktopEntries.clear();
+	this->lowercaseDesktopEntries.clear();
 
-				qCDebug(logDesktopEntry) << "Removed desktop entry:" << id;
-			}
-			break;
-		}
+	this->scanDesktopEntries();
+
+	QVector<DesktopEntry*> newApplications;
+	for (auto& entry: this->desktopEntries.values()) {
+		if (!entry->noDisplay()) {
+			newApplications.append(entry);
 		}
 	}
 
-	if (needsUpdate) {
-		this->updateApplicationModel();
-		emit applicationsChanged();
+	this->mApplications.diffUpdate(newApplications);
+
+	for (auto* e: oldEntries) {
+		if (!this->desktopEntries.contains(e->mId)) {
+			e->deleteLater();
+		}
 	}
+
+	emit applicationsChanged();
 }
 
 QString DesktopEntryManager::extractIdFromPath(const QString& path) {

src/core/desktopentrymonitor.cpp

@@ -30,12 +30,6 @@ DesktopEntryMonitor::DesktopEntryMonitor(QObject* parent): QObject(parent) {
 	    this,
 	    &DesktopEntryMonitor::onDirectoryChanged
 	);
-	connect(
-	    this->watcher,
-	    &QFileSystemWatcher::fileChanged,
-	    this,
-	    &DesktopEntryMonitor::onFileChanged
-	);
 	connect(this->debounceTimer, &QTimer::timeout, this, &DesktopEntryMonitor::processChanges);
 
 	// Start monitoring
@@ -68,18 +62,6 @@ void DesktopEntryMonitor::scanAndWatch(const QString& dirPath) {
 		qCDebug(logDesktopMonitor) << "Added directory to watcher:" << dirPath;
 	}
 
-	// Add .desktop files
-	for (const auto& entry: dir.entryInfoList({"*.desktop"}, QDir::Files)) {
-		auto path = entry.absoluteFilePath();
-		if (!this->watchedFiles.contains(path)) {
-			if (this->watcher->addPath(path)) {
-				this->fileTimestamps[path] = entry.lastModified();
-				this->watchedFiles.insert(path);
-				qCDebug(logDesktopMonitor) << "Monitoring file:" << path;
-			}
-		}
-	}
-
 	// Recurse into subdirs
 	for (const auto& sub: dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot)) {
 		this->scanAndWatch(dir.absoluteFilePath(sub));
@@ -94,52 +76,11 @@ void DesktopEntryMonitor::onDirectoryChanged(const QString& path) {
 	if (!dir.exists()) {
 		qCDebug(logDesktopMonitor) << "Directory no longer exists, cleaning up:" << path;
 		this->watcher->removePath(path);
-
-		// Remove all watched files from this directory and its subdirectories
-		for (auto it = this->watchedFiles.begin(); it != this->watchedFiles.end();) {
-			const QString& watchedFile = *it;
-			if (watchedFile.startsWith(path + "/") || watchedFile == path) {
-				this->watcher->removePath(watchedFile);
-				this->fileTimestamps.remove(watchedFile);
-				this->queueChange(ChangeEvent::Removed, watchedFile);
-				qCDebug(logDesktopMonitor) << "Removed file due to directory deletion:" << watchedFile;
-				it = this->watchedFiles.erase(it);
-			} else {
-				++it;
-			}
-		}
+		// Directory removal will be handled by full rescan
+		this->queueChange(ChangeEvent::Modified, path); // Trigger full rescan
 		return;
 	}
 
-	QList<QString> currentFiles = dir.entryList({"*.desktop"}, QDir::Files);
-
-	// Check for new files
-	for (const QString& file: currentFiles) {
-		QString fullPath = dir.absoluteFilePath(file);
-		if (!this->watchedFiles.contains(fullPath)) {
-			if (this->watcher->addPath(fullPath)) {
-				this->fileTimestamps[fullPath] = QFileInfo(fullPath).lastModified();
-				this->watchedFiles.insert(fullPath);
-				this->queueChange(ChangeEvent::Added, fullPath);
-				qCDebug(logDesktopMonitor) << "New desktop file detected:" << fullPath;
-			}
-		}
-	}
-
-	// Check for deleted files
-	for (auto it = this->watchedFiles.begin(); it != this->watchedFiles.end();) {
-		const QString& watchedFile = *it;
-		if (QFileInfo(watchedFile).dir().absolutePath() == path && !QFile::exists(watchedFile)) {
-			this->watcher->removePath(watchedFile);
-			this->fileTimestamps.remove(watchedFile);
-			this->queueChange(ChangeEvent::Removed, watchedFile);
-			qCDebug(logDesktopMonitor) << "Desktop file removed:" << watchedFile;
-			it = this->watchedFiles.erase(it);
-		} else {
-			++it;
-		}
-	}
-
 	// Check for new subdirectories
 	QList<QString> subdirs = dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot);
 	for (const QString& subdir: subdirs) {
@@ -148,27 +89,9 @@ void DesktopEntryMonitor::onDirectoryChanged(const QString& path) {
 			this->scanAndWatch(subdirPath);
 		}
 	}
-}
-
-void DesktopEntryMonitor::onFileChanged(const QString& path) {
-	if (QFileInfo(path).suffix().toLower() != "desktop") return;
 
-	QFileInfo info(path);
-	if (info.exists()) {
-		QDateTime currentModified = info.lastModified();
-		if (this->fileTimestamps.value(path) != currentModified) {
-			this->fileTimestamps[path] = currentModified;
-			this->queueChange(ChangeEvent::Modified, path);
-			qCDebug(logDesktopMonitor) << "Desktop file modified:" << path;
-		}
-	} else {
-		// File was deleted
-		this->watcher->removePath(path);
-		this->fileTimestamps.remove(path);
-		this->watchedFiles.remove(path);
-		this->queueChange(ChangeEvent::Removed, path);
-		qCDebug(logDesktopMonitor) << "Desktop file removed:" << path;
-	}
+	// Queue a change to trigger full rescan of all desktop paths
+	this->queueChange(ChangeEvent::Modified, path);
 }
 
 void DesktopEntryMonitor::queueChange(ChangeEvent event, const QString& path) {
@@ -179,10 +102,12 @@ void DesktopEntryMonitor::queueChange(ChangeEvent event, const QString& path) {
 void DesktopEntryMonitor::processChanges() {
 	if (this->pendingChanges.isEmpty()) return;
 
-	qCDebug(logDesktopMonitor) << "Processing" << this->pendingChanges.size() << "pending changes";
+	qCDebug(logDesktopMonitor) << "Processing directory changes, triggering full rescan";
 
-	QHash<QString, ChangeEvent> changes = this->pendingChanges;
+	// Clear pending changes since we're doing a full rescan
 	this->pendingChanges.clear();
 
-	emit desktopEntriesChanged(changes);
+	// Emit with empty hash to signal full rescan needed
+	QHash<QString, ChangeEvent> emptyChanges;
+	emit desktopEntriesChanged(emptyChanges);
 }

src/core/desktopentrymonitor.hpp

@@ -1,10 +1,8 @@
 #pragma once
 
-#include <qdatetime.h>
 #include <qfilesystemwatcher.h>
 #include <qhash.h>
 #include <qobject.h>
-#include <qset.h>
 #include <qstringlist.h>
 #include <qtimer.h>
 
@@ -22,7 +20,6 @@ class DesktopEntryMonitor: public QObject {
 
 private slots:
 	void onDirectoryChanged(const QString& path);
-	void onFileChanged(const QString& path);
 	void processChanges();
 
 private:
@@ -34,8 +31,6 @@ private slots:
 
 	QFileSystemWatcher* watcher;
 	QStringList desktopPaths;
-	QHash<QString, QDateTime> fileTimestamps;
-	QSet<QString> watchedFiles;
 	QTimer* debounceTimer;
 	QHash<QString, ChangeEvent> pendingChanges;
 };