File indexing completed on 2024-04-28 05:30:16

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2021 David Edmundson <davidedmundson@kde.org>
     SPDX-FileCopyrightText: 2020 Roman Gilg <subdiff@gmail.com>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "ftrace.h"
 
 #include <QDBusConnection>
 #include <QDebug>
 #include <QDir>
 #include <QFile>
 #include <QFileInfo>
 #include <QScopeGuard>
 #include <QTextStream>
 
 namespace KWin
 {
 KWIN_SINGLETON_FACTORY(KWin::FTraceLogger)
 
 FTraceLogger::FTraceLogger(QObject *parent)
     : QObject(parent)
 {
     if (qEnvironmentVariableIsSet("KWIN_PERF_FTRACE")) {
         setEnabled(true);
     } else {
         QDBusConnection::sessionBus().registerObject(QStringLiteral("/FTrace"), this, QDBusConnection::ExportScriptableContents);
     }
 }
 
 bool FTraceLogger::isEnabled() const
 {
     return m_file.isOpen();
 }
 
 void FTraceLogger::setEnabled(bool enabled)
 {
     QMutexLocker lock(&m_mutex);
     if (enabled == isEnabled()) {
         return;
     }
 
     if (enabled) {
         open();
     } else {
         m_file.close();
     }
     Q_EMIT enabledChanged();
 }
 
 bool FTraceLogger::open()
 {
     const QString path = filePath();
     if (path.isEmpty()) {
         return false;
     }
 
     m_file.setFileName(path);
     if (!m_file.open(QIODevice::WriteOnly)) {
         qWarning() << "No access to trace marker file at:" << path;
     }
     return true;
 }
 
 QString FTraceLogger::filePath()
 {
     if (qEnvironmentVariableIsSet("KWIN_PERF_FTRACE_FILE")) {
         return qgetenv("KWIN_PERF_FTRACE_FILE");
     }
 
     QFile mountsFile("/proc/mounts");
     if (!mountsFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
         qWarning() << "No access to mounts file. Can not determine trace marker file location.";
         return QString();
     }
 
     auto lineInfo = [](const QString &line) {
         const int start = line.indexOf(' ') + 1;
         const int end = line.indexOf(' ', start);
         const QString dirPath(line.mid(start, end - start));
         if (dirPath.isEmpty() || !QFileInfo::exists(dirPath)) {
             return QFileInfo();
         }
         return QFileInfo(QDir(dirPath), QStringLiteral("trace_marker"));
     };
     QFileInfo markerFileInfo;
     QTextStream mountsIn(&mountsFile);
     QString mountsLine = mountsIn.readLine();
 
     while (!mountsLine.isNull()) {
         if (mountsLine.startsWith("tracefs")) {
             const auto info = lineInfo(mountsLine);
             if (info.exists()) {
                 markerFileInfo = info;
                 break;
             }
         }
         if (mountsLine.startsWith("debugfs")) {
             markerFileInfo = lineInfo(mountsLine);
         }
         mountsLine = mountsIn.readLine();
     }
     mountsFile.close();
     if (!markerFileInfo.exists()) {
         qWarning() << "Could not determine trace marker file location from mounts.";
         return QString();
     }
 
     return markerFileInfo.absoluteFilePath();
 }
 
 FTraceDuration::~FTraceDuration()
 {
     FTraceLogger::self()->trace(m_message, " end_ctx=", m_context);
 }
 
 }
 
 #include "moc_ftrace.cpp"