refactor: Add logging category to debug log.

This is useful to distinguish log sources. In the future, we can use
this to e.g. make more verbose logging optional or allow
category-filtering in the debug log view.

src/appmanager.cpp

@@ -105,11 +105,14 @@ void logMessageHandler(QtMsgType type, const QMessageLogContext& ctxt, const QSt
     }
 
     const QString file = canonicalLogFilePath(ctxt.file);
+    const QString category =
+        ctxt.category ? QString::fromUtf8(ctxt.category) : QStringLiteral("default");
 
     // Time should be in UTC to save user privacy on log sharing
     QTime time = QDateTime::currentDateTime().toUTC().time();
     QString logPrefix =
-        QStringLiteral("[%1 UTC] %2:%3 : ").arg(time.toString("HH:mm:ss.zzz")).arg(file).arg(ctxt.line);
+        QStringLiteral("[%1 UTC] (%2) %3:%4 : ")
+            .arg(time.toString("HH:mm:ss.zzz"), category, file, QString::number(ctxt.line));
     switch (type) {
     case QtDebugMsg:
         logPrefix += "Debug";

src/model/debug/debuglogmodel.cpp

@@ -49,13 +49,15 @@ QString renderMsgType(QtMsgType type)
 
 QList<DebugLogModel::LogEntry> parse(const QStringList& logs)
 {
+    // Regex extraction of log entry
+    // [12:35:16.634 UTC] (default) src/core/core.cpp:370 : Debug: Connected to a TCP relay
+    //  ^                  ^        ^                 ^     ^      ^
+    //  time              category  file              line  type   message
+    static const QRegularExpression re(
+        R"(\[([0-9:.]*) UTC\](?: \(([^)]*)\))? (.*?):(\d+) : ([^:]+): (.*))");
+
     QList<DebugLogModel::LogEntry> result;
     for (const QString& log : logs) {
-        // Regex extraction of log entry
-        // [12:35:16.634 UTC] src/core/core.cpp:370 : Debug: Connected to a TCP relay
-        //  ^                 ^                 ^     ^      ^
-        //  time              file              line  type   message
-        const QRegularExpression re(R"(\[(.*) UTC\] (.*):(\d+) : ([^:]+): (.*))");
         const auto match = re.match(log);
         if (!match.hasMatch()) {
             qWarning() << "Failed to parse log entry:" << log;
@@ -65,23 +67,24 @@ QList<DebugLogModel::LogEntry> parse(const QStringList& logs)
         DebugLogModel::LogEntry entry;
         entry.index = result.size();
         entry.time = match.captured(1);
-        entry.file = match.captured(2);
-        entry.line = match.captured(3).toInt();
-        entry.type = parseMsgType(match.captured(4));
-        entry.message = match.captured(5);
+        entry.category = match.captured(2);
+        if (entry.category.isEmpty()) {
+            entry.category = QStringLiteral("default");
+        }
+        entry.file = match.captured(3);
+        entry.line = match.captured(4).toInt();
+        entry.type = parseMsgType(match.captured(5));
+        entry.message = match.captured(6);
         result.append(entry);
     }
     return result;
 }
 
 QString render(const DebugLogModel::LogEntry& entry)
 {
-    return QStringLiteral("[%1] %2:%3 : %4: %5")
-        .arg(entry.time)
-        .arg(entry.file)
-        .arg(entry.line)
-        .arg(renderMsgType(entry.type))
-        .arg(entry.message);
+    return QStringLiteral("[%1 UTC] (%2) %3:%4 : %5: %6")
+        .arg(entry.time, entry.category, entry.file, QString::number(entry.line),
+             renderMsgType(entry.type), entry.message);
 }
 
 bool filterAccepts(DebugLogModel::Filter filter, QtMsgType type)

src/model/debug/debuglogmodel.h

@@ -30,6 +30,7 @@ class DebugLogModel : public QAbstractListModel
         int index;
 
         QString time;
+        QString category;
         QString file;
         int line;
         QtMsgType type;