kdelibs/kded/kded.cpp

// vim: expandtab sw=4 ts=4
/*  This file is part of the KDE libraries
 *  Copyright (C) 1999 David Faure <faure@kde.org>
 *  Copyright (C) 2000 Waldo Bastian <bastian@kde.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License version 2 as published by the Free Software Foundation;
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 **/

#include "kded.h"
#include "kdedadaptor.h"
#include "kdedmodule.h"

#include <kdeversion.h>
#include <kapplication.h>
#include <kcmdlineargs.h>
#include <kaboutdata.h>
#include <klocale.h>
#include <kglobal.h>
#include <kconfig.h>
#include <kconfiggroup.h>
#include <kdebug.h>
#include <kdirwatch.h>
#include <kstandarddirs.h>
#include <kservicetypetrader.h>

#include <QFile>
#include <QProcess>
#include <QHostInfo>
#include <QDBusReply>
#include <QDBusConnectionInterface>

#include <unistd.h>

#define KDED_EXENAME "kded4"

#define MODULES_PATH "/modules/"
#define MODULES_PATH_SIZE 9

Kded *Kded::_self = 0;

static bool bCheckSycoca = true;
static bool bCheckStamps = true;
static bool bCheckHostname = true;
static int iHostnamePollInterval = 5000;

QT_BEGIN_NAMESPACE
extern Q_DBUS_EXPORT void qDBusAddSpyHook(void (*)(const QDBusMessage&));
QT_END_NAMESPACE

static void runBuildSycoca()
{
    const QString exe = KStandardDirs::findExe(KBUILDSYCOCA_EXENAME);
    Q_ASSERT(!exe.isEmpty());
    QStringList args;
    if (bCheckStamps) {
        args.append("--checkstamps");
    }
    if (QProcess::execute(exe, args) != 0) {
        kWarning() << "a problem occured while running" << exe;
    }
}

static void runDontChangeHostname(const QByteArray &oldName, const QByteArray &newName)
{
    const QString exe = KStandardDirs::findExe(QString::fromLatin1("kdontchangethehostname"));
    Q_ASSERT(!exe.isEmpty());
    QStringList args;
    args.append(QFile::decodeName(oldName));
    args.append(QFile::decodeName(newName));
    if (QProcess::execute(exe, args) != 0) {
        kWarning() << "a problem occured while running" << exe;
    }
}

Kded::Kded(QObject *parent)
    : QObject(parent),
    m_pDirWatch(nullptr),
    m_pTimer(nullptr),
    m_hTimer(nullptr)
{
    _self = this;

    new KBuildsycocaAdaptor(this);
    new KdedAdaptor(this);

    QDBusConnection session = QDBusConnection::sessionBus();
    session.registerObject("/kbuildsycoca", this);
    session.registerObject("/kded", this);
    session.registerService("org.kde.kded");

    updateResourceList();
    updateDirWatch();
    initModules();

    qDBusAddSpyHook(messageFilter);

    m_pTimer = new QTimer(this);
    m_pTimer->setSingleShot(true);
    connect(m_pTimer, SIGNAL(timeout()), this, SLOT(recreate()));

    if (bCheckHostname) {
        // Watch for hostname changes
        m_hTimer = new QTimer(this);
        m_hTimer->start(iHostnamePollInterval); // repetitive timer (not single-shot)
        connect(m_hTimer, SIGNAL(timeout()), this, SLOT(checkHostname()));
        checkHostname();
    }
}

Kded::~Kded()
{
    _self = 0;

    QDBusConnection session = QDBusConnection::sessionBus();
    session.unregisterObject("/kbuildsycoca");
    session.unregisterObject("/kded");
    session.unregisterService("org.kde.kded");

    m_pTimer->stop();
    delete m_pTimer;
    delete m_pDirWatch;

    if (m_hTimer) {
        m_hTimer->stop();
        delete m_hTimer;
    }

    QHashIterator<QString,KDEDModule*> it(m_modules);
    while (it.hasNext()) {
        it.next();
        KDEDModule* module(it.value());

        // first disconnect otherwise slotKDEDModuleRemoved() is called
        // and changes m_modules while we're iterating over it
        disconnect(module, SIGNAL(moduleDeleted(KDEDModule*)),
                   this, SLOT(slotKDEDModuleRemoved(KDEDModule*)));

        delete module;
    }
}

// on-demand module loading
// this function is called by the D-Bus message processing function before
// calls are delivered to objects
void Kded::messageFilter(const QDBusMessage &message)
{
    // This happens when kded goes down and some modules try to clean up.
    if (!self()) {
        return;
    }

    if (message.type() != QDBusMessage::MethodCallMessage) {
        return;
    }

    QString obj = message.path();
    if (!obj.startsWith(QLatin1String(MODULES_PATH))) {
        return;
    }

    // Remove the <MODULES_PATH> part
    obj = obj.mid(MODULES_PATH_SIZE);

    // Remove the part after the modules name
    int index = obj.indexOf('/');
    if (index != -1) {
        obj = obj.left(index);
    }

    if (self()->m_dontLoad.value(obj, 0)) {
        return;
    }

    KDEDModule *module = self()->loadModule(obj, true);
    if (!module) {
        kDebug(7020) << "Failed to load module for " << obj;
    }
    Q_UNUSED(module);
}

static int phaseForModule(const KService::Ptr &service)
{
    const QVariant phasev = service->property("X-KDE-Kded-phase", QVariant::Int);
    return (phasev.isValid() ? phasev.toInt() : 2);
}

static bool allowedForDesktop(const KService::Ptr &service, const QString &desktop)
{
    const QString only_show_in = service->property("OnlyShowIn", QVariant::String).toString();
    kDebug(7020) << "only_show_in" << service->entryPath() << only_show_in;
    if (only_show_in.isEmpty()) {
        return true;
    }
    const QStringList only_show_in_list = only_show_in.split(QLatin1Char(';'));
    return only_show_in_list.contains(desktop);
}

static bool excludedForDesktop(const KService::Ptr &service, const QString &desktop)
{
    const QString not_show_in = service->property("NotShowIn", QVariant::String).toString();
    kDebug(7020) << "not_show_in" << service->entryPath() << not_show_in;
    if (not_show_in.isEmpty()) {
        return false;
    }
    const QStringList not_show_in_list = not_show_in.split(QLatin1Char(';'));
    return !not_show_in_list.contains(desktop);
}

void Kded::initModules()
{
    m_dontLoad.clear();
    const QString current_desktop = QString::fromLocal8Bit(qgetenv("XDG_CURRENT_DESKTOP"));
    kDebug(7020) << "current_desktop" << current_desktop;

    // Preload kded modules.
    const KService::List kdedModules = KServiceTypeTrader::self()->query("KDEDModule");
    for (int phase = 0; phase < 2; phase++) {
        foreach (const KService::Ptr service, kdedModules) {
            const int module_phase = phaseForModule(service);
            // Should the service be loaded in this phase or later?
            if (module_phase != phase) {
                continue;
            }

            // Should the service load on startup?
            const bool autoload = isModuleAutoloaded(service);
            bool prevent_autoload = false;
            switch( module_phase ) {
                case 0: {
                    // always autoload
                    break;
                }
                case 1: {
                    // autoload only in the current desktop?
                    if (current_desktop.isEmpty()) {
                        prevent_autoload = true;
                        break;
                    }

                    if (!prevent_autoload && !allowedForDesktop(service, current_desktop)) {
                        prevent_autoload = true;
                    }

                    if (!prevent_autoload && excludedForDesktop(service, current_desktop)) {
                        prevent_autoload = true;
                    }
                    break;
                }
                default: {
                    Q_ASSERT(false);
                    break;
                }
            }

            // Load the module if necessary and allowed
            if (autoload && !prevent_autoload) {
                if (!loadModule(service, false)) {
                    continue;
                }
            }

            // Remember if the module is allowed to load on demand
            bool loadOnDemand = isModuleLoadedOnDemand(service);
            if (!loadOnDemand) {
                noDemandLoad(service->desktopEntryName());
            }

            // In case of reloading the configuration it is possible for a module
            // to run even if it is now allowed to. Stop it then.
            if (!loadOnDemand && !autoload) {
                unloadModule(service->desktopEntryName().toLatin1());
            }
        }
    }
}

void Kded::loadSecondPhase()
{
    kDebug(7020) << "Loading second phase autoload";
    KSharedConfig::Ptr config = KGlobal::config();
    KService::List kdedModules = KServiceTypeTrader::self()->query("KDEDModule");
    foreach (const KService::Ptr service, kdedModules) {
        const bool autoload = isModuleAutoloaded(service);
        if (autoload && phaseForModule(service) == 2) {
            // kDebug(7020) << "2nd phase: loading" << service->desktopEntryName();
            loadModule(service, false);
        }
    }
}

void Kded::noDemandLoad(const QString &obj)
{
    m_dontLoad.insert(obj.toLatin1(), this);
}

void Kded::setModuleAutoloading(const QString &obj, bool autoload)
{
    KSharedConfig::Ptr config = KGlobal::config();
    // Ensure the service exists.
    KService::Ptr service = KService::serviceByDesktopPath("kded/" + obj + ".desktop");
    if (!service) {
        return;
    }
    KConfigGroup cg(config, QString("Module-%1").arg(service->desktopEntryName()));
    cg.writeEntry("autoload", autoload);
    cg.sync();
}

bool Kded::isModuleAutoloaded(const QString &obj) const
{
    KService::Ptr s = KService::serviceByDesktopPath("kded/" + obj + ".desktop");
    if (!s) {
        return false;
    }
    return isModuleAutoloaded(s);
}

bool Kded::isModuleAutoloaded(const KService::Ptr &module) const
{
    KSharedConfig::Ptr config = KGlobal::config();
    bool autoload = module->property("X-KDE-Kded-autoload", QVariant::Bool).toBool();
    KConfigGroup cg(config, QString("Module-%1").arg(module->desktopEntryName()));
    autoload = cg.readEntry("autoload", autoload);
    return autoload;
}

bool Kded::isModuleLoadedOnDemand(const QString &obj) const
{
    KService::Ptr s = KService::serviceByDesktopPath("kded/" + obj + ".desktop");
    if (!s) {
        return false;
    }
    return isModuleLoadedOnDemand(s);
}

bool Kded::isModuleLoadedOnDemand(const KService::Ptr &module) const
{
    KSharedConfig::Ptr config = KGlobal::config();
    bool loadOnDemand = true;
    QVariant p = module->property("X-KDE-Kded-load-on-demand", QVariant::Bool);
    if (p.isValid() && (p.toBool() == false)) {
        loadOnDemand = false;
    }
    return loadOnDemand;
}

KDEDModule *Kded::loadModule(const QString &obj, bool onDemand)
{
    // Make sure this method is only called with valid module names.
    Q_ASSERT(obj.indexOf('/') == -1);

    KDEDModule *module = m_modules.value(obj, 0);
    if (module) {
        return module;
    }
    KService::Ptr s = KService::serviceByDesktopPath("kded/" + obj + ".desktop");
    return loadModule(s, onDemand);
}

KDEDModule *Kded::loadModule(const KService::Ptr& s, bool onDemand)
{
    if (s && !s->library().isEmpty()) {
        QString obj = s->desktopEntryName();
        KDEDModule *oldModule = m_modules.value(obj, 0);
        if (oldModule) {
            return oldModule;
        }

        if (onDemand) {
            QVariant p = s->property("X-KDE-Kded-load-on-demand", QVariant::Bool);
            if (p.isValid() && (p.toBool() == false)) {
                noDemandLoad(s->desktopEntryName());
                return 0;
            }
        }

        QString libname = "kded_" + s->library();
        KPluginLoader loader(libname);

        KPluginFactory *factory = loader.factory();
        KDEDModule *module = 0;
        if (factory) {
            module = factory->create<KDEDModule>(this);
        }
        if (module) {
            module->setModuleName(obj);
            m_modules.insert(obj, module);
            // m_libs.insert(obj, lib);
            connect(module, SIGNAL(moduleDeleted(KDEDModule*)), SLOT(slotKDEDModuleRemoved(KDEDModule*)));
            kDebug(7020) << "Successfully loaded module" << obj;
            return module;
        } else {
            kDebug(7020) << "Could not load module" << obj << loader.errorString();
            // loader.unload();
        }
    }
    return 0;
}

bool Kded::unloadModule(const QString &obj)
{
    KDEDModule *module = m_modules.value(obj, 0);
    if (!module) {
        return false;
    }
    kDebug(7020) << "Unloading module" << obj;
    m_modules.remove(obj);
    delete module;
    return true;
}

QStringList Kded::loadedModules()
{
    return m_modules.keys();
}

void Kded::slotKDEDModuleRemoved(KDEDModule *module)
{
    m_modules.remove(module->moduleName());
    // QLibrary *lib = m_libs.take(module->moduleName());
    // if (lib) {
    //     lib->unload();
    // }
}

void Kded::updateDirWatch()
{
    if (!bCheckSycoca) {
        return;
    }

    delete m_pDirWatch;
    m_pDirWatch = new KDirWatch(this);
    connect(m_pDirWatch, SIGNAL(dirty(QString)), this, SLOT(update(QString)));

    foreach(const QString &it, m_allResourceDirs) {
        m_pDirWatch->addDir(it, true);
    }
}

void Kded::updateResourceList()
{
    KSycoca::clearCaches();

    foreach(const QString &it, KSycoca::self()->allResourceDirs()) {
        if (!m_allResourceDirs.contains(it)) {
            m_allResourceDirs.append(it);
        }
    }
}

void Kded::recreate()
{
    runBuildSycoca();
    updateResourceList();
    updateDirWatch();

    // NOTE: phase 2 is done by ksmserver, i.e. it will be redone on the next session
    initModules();
}

void Kded::update(const QString& path)
{
    Q_UNUSED(path);
    if (!m_pTimer->isActive()) {
        m_pTimer->start(5000);
    }
}

void Kded::checkHostname()
{
    const QByteArray newHostname = QHostInfo::localHostName().toUtf8();
    if (newHostname.isEmpty()) {
        return;
    }

    if (m_hostname.isEmpty()) {
       m_hostname = newHostname;
       return;
    }

    if (m_hostname == newHostname) {
       return;
    }

    runDontChangeHostname(m_hostname, newHostname);
    m_hostname = newHostname;
}

KBuildsycocaAdaptor::KBuildsycocaAdaptor(QObject *parent)
    : QDBusAbstractAdaptor(parent)
{
}

void KBuildsycocaAdaptor::recreate()
{
    Kded::self()->recreate();
}

int main(int argc, char *argv[])
{
    KAboutData aboutData("kded" /*don't change this one to kded4! dbus registration should be org.kde.kded etc.*/,
        "kdelibs4", ki18n("KDE Daemon"),
        KDE_VERSION_STRING,
        ki18n("KDE Daemon - triggers Sycoca database updates when needed"));

    KCmdLineArgs::init(argc, argv, &aboutData);

    KComponentData componentData(&aboutData);
    KSharedConfig::Ptr config = componentData.config(); // Enable translations.

    KApplication app;
    app.setQuitOnLastWindowClosed(false);

    QDBusConnection session = QDBusConnection::sessionBus();
    if (!session.isConnected()) {
        kWarning() << "No DBUS session-bus found. Check if you have started the DBUS server.";
        return 1;
    }
    QDBusReply<bool> sessionReply = session.interface()->isServiceRegistered("org.kde.kded");
    if (sessionReply.isValid() && sessionReply.value() == true) {
        kWarning() << "Another instance of kded4 is already running!";
        return 2;
    }

    KConfigGroup cg(config, "General");
    bCheckSycoca = cg.readEntry("CheckSycoca", true);
    bCheckStamps = cg.readEntry("CheckFileStamps", true);
    bCheckHostname = cg.readEntry("CheckHostname", true);
    iHostnamePollInterval = cg.readEntry("HostnamePollInterval", 5000);

    Kded kded(&app);

    return app.exec(); // keep running
}

#include "moc_kded.cpp"