perf: optimize XSettings1 startup — remove Before constraint, skip redundant init, clean up debug code

Remove Before=org.dde.session.Daemon1.service so XSettings1 and dde-session-daemon
start in parallel. On subsequent boots where scale factor is already persisted in
DConfig, skip RandR monitor enumeration, Plymouth scaling, and Greeter Qt theme
update (~100-350ms saved). Remove leftover debug code in getXcbAtomProperty that
queried atom type names and hex-dumped binary property values on every call.
Remove unnecessary isServiceRegistered guard in DSMRegister. Add startup timing
logs (qWarning level) for future profiling.

移除对 dde-session-daemon 的 Before 排序约束，使 XSettings1 和 dde-session-daemon
可以并行启动。后续登录时跳过 RandR 枚举、Plymouth 缩放和 Greeter 更新
（节省约 100-350ms）。清理 getXcbAtomProperty 中的调试遗留代码（每次读取属性
都查询原子类型名称并 hex 转储二进制值）。移除 DSMRegister 中不必要的
isServiceRegistered 检查。添加启动计时日志用于性能分析。

Log: perf: optimize XSettings1 startup — remove Before constraint, skip redundant init, clean up debug code
Change-Id: I2b5f4e9404bc2af10e077d936698a2b2569d2a8e

Author: yixinshark

src/plugin-qt/xsettings/impl/xsettingsmanager.cpp

@@ -11,6 +11,7 @@
 #include <QDebug>
 #include <QDir>
 #include <QDirIterator>
+#include <QElapsedTimer>
 #include <QProcessEnvironment>
 #include <QStandardPaths>
 #include <QThreadPool>
@@ -29,16 +30,50 @@ XSettingsManager::XSettingsManager(QObject *parent)
     , m_sysDaemonInterface(new QDBusInterface("com.deepin.daemon.Daemon", "/com/deepin/daemon/Daemon", "com.deepin.daemon.Daemon", QDBusConnection::systemBus()))
     , m_xcbUtils(XcbUtils::getInstance())
 {
+    QElapsedTimer timer;
+    timer.start();
+    qWarning() << "[xsettings] ctor start";
+
     connect(m_settingDconfig, &DTK_CORE_NAMESPACE::DConfig::valueChanged, this, &XSettingsManager::handleDConfigChangedCb);
-    setScreenScaleFactors(getScreenScaleFactors(), false);
-    adjustScaleFactor(getRecommendedScaleFactor());
-    setSettings(getSettingsInSchema());
 
+    double scale = 0;
+    if (m_settingDconfig->isValid()) {
+        scale = m_settingDconfig->value("scale-factor").toDouble();
+    }
+    qWarning() << "[xsettings] after scale check" << timer.elapsed() << "ms" << "scale=" << scale;
+
+    // scale <= 0 is invalid, use recommended scale factor
+    if (scale <= 0) {
+        setScreenScaleFactors(getScreenScaleFactors(), false);
+        adjustScaleFactor(getRecommendedScaleFactor());
+        qWarning() << "[xsettings] after first-boot scale init" << timer.elapsed() << "ms";
+    }
+
+    QElapsedTimer stageTimer;
+    stageTimer.start();
+    QVector<XsSetting> schemaSettings = getSettingsInSchema();
+    qWarning() << "[xsettings] getSettingsInSchema" << stageTimer.elapsed() << "ms" << "count=" << schemaSettings.size();
+
+    stageTimer.restart();
+    setSettings(schemaSettings);
+    qWarning() << "[xsettings] setSettings(schema)" << stageTimer.elapsed() << "ms";
+
+    stageTimer.restart();
     updateDPI();
+    qWarning() << "[xsettings] updateDPI" << stageTimer.elapsed() << "ms";
+
+    stageTimer.restart();
     updateXResources();
+    qWarning() << "[xsettings] updateXResources" << stageTimer.elapsed() << "ms";
+
     QThreadPool::globalInstance()->start([this]() {
+        QElapsedTimer firefoxTimer;
+        firefoxTimer.start();
         updateFirefoxDPI();
+        qWarning() << "[xsettings] updateFirefoxDPI" << firefoxTimer.elapsed() << "ms";
     });
+
+    qWarning() << "[xsettings] ctor done" << timer.elapsed() << "ms";
 }
 
 ArrayOfColor XSettingsManager::getColor(const QString &prop)
@@ -290,7 +325,10 @@ double calcRecommendedScaleFactor(double widthPx, double heightPx, double widthM
 
 double XSettingsManager::getRecommendedScaleFactor()
 {
+    QElapsedTimer t;
+    t.start();
     QList<XcbUtils::MonitorSizeInfo> monitors = XcbUtils::getInstance().getMonitorSizeInfos();
+    qWarning() << "[xsettings] getMonitorSizeInfos" << t.elapsed() << "ms" << "count=" << monitors.size();
     if (monitors.isEmpty()) {
         return 1.0;
     }

src/plugin-qt/xsettings/misc/org.deepin.dde.XSettings1.service

@@ -7,8 +7,6 @@ CollectMode=inactive-or-failed
 PartOf=dde-session-pre.target
 Before=dde-session-pre.target
 
-Before=org.dde.session.Daemon1.service
-
 [Service]
 Type=dbus
 BusName=org.deepin.dde.XSettings1

src/plugin-qt/xsettings/modules/api/xcbutils.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2025 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2025 - 2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: LGPL-3.0-or-later
 #include "xcbutils.h"
@@ -9,12 +9,17 @@
 #include <xcb/randr.h>
 #include <xcb/xcb.h>
 
+#include <QElapsedTimer>
+#include <QLoggingCategory>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 bool xcb_debug = 1;
 
+Q_LOGGING_CATEGORY(xsettingsTimingLog, "dde.xsettings.timing")
+
 XcbUtils &XcbUtils::getInstance()
 {
     static XcbUtils xcbUtils;
@@ -251,6 +256,8 @@ QList<XcbUtils::MonitorSizeInfo> XcbUtils::getMonitorSizeInfos()
 // 获取 _XSETTINGS_SETTINGS 属性
 QByteArray XcbUtils::getXcbAtomProperty(xcb_atom_t atom)
 {
+    QElapsedTimer t;
+    t.start();
     bool more = true;
     int offset = 0;
     xcb_get_property_cookie_t cookie;
@@ -271,34 +278,17 @@ QByteArray XcbUtils::getXcbAtomProperty(xcb_atom_t atom)
         reply = xcb_get_property_reply(connection, cookie, &error);
         // 在窗口无效时，应当认为此native settings未初始化完成
         if (error && error->error_code == 3) {
+            qCWarning(xsettingsTimingLog) << "getXcbAtomProperty" << t.elapsed() << "ms" << "error=" << error->error_code;
             return settings;
         }
 
-        // 查询这个原子类型的名称
-        xcb_get_atom_name_cookie_t type_name_cookie = xcb_get_atom_name(connection, reply->type);
-        xcb_get_atom_name_reply_t *type_name_reply = xcb_get_atom_name_reply(connection, type_name_cookie, NULL);
-
-        if (type_name_reply) {
-            int name_len = xcb_get_atom_name_name_length(type_name_reply);
-            char *name = xcb_get_atom_name_name(type_name_reply);
-            qWarning("属性类型名称: %.*s", name_len, name);
-            free(type_name_reply);
-        }
-        void *value = xcb_get_property_value(reply);
-        int value_len = xcb_get_property_value_length(reply);
-        qWarning("属性值(字符串): %d |%s\n", value_len, (char *)value);
-
         const auto property_value_length = xcb_get_property_value_length(reply);
         settings.append(static_cast<const char *>(xcb_get_property_value(reply)), property_value_length);
-        QStringList hex;
-        for (int i = 0; i < property_value_length; ++i) {
-            hex.append(QString::number((uint8_t)settings[i]));
-            // hex<<(uint8_t)array.at(i);
-        }
         offset += property_value_length;
         more = reply->bytes_after != 0;
         free(reply);
     }
+    qCWarning(xsettingsTimingLog) << "getXcbAtomProperty" << t.elapsed() << "ms" << "size=" << settings.size();
     return settings;
 }
 
@@ -321,7 +311,10 @@ bool XcbUtils::changeSettingProp(QByteArray data)
 
 void XcbUtils::updateXResources(QVector<QPair<QString, QString>> xresourceInfos)
 {
+    QElapsedTimer t;
+    t.start();
     QString datas = getXResources();
+    qint64 getMs = t.elapsed();
 
     if (datas.isEmpty()) {
         xresourceInfos.push_back(qMakePair(QString("*customization"), QString("-color")));
@@ -343,9 +336,11 @@ void XcbUtils::updateXResources(QVector<QPair<QString, QString>> xresourceInfos)
         }
     }
 
+    qint64 mergeMs = t.elapsed();
     datas = XcbUtils::marshalXResources(xresourceInfos);
 
     XcbUtils::setXResources(const_cast<char *>(datas.toStdString().c_str()), datas.length());
+    qCWarning(xsettingsTimingLog) << "updateXResources get=" << getMs << "ms" << "merge=" << (mergeMs - getMs) << "ms" << "set=" << (t.elapsed() - mergeMs) << "ms" << "total=" << t.elapsed() << "ms";
 }
 
 char *XcbUtils::getXResources()

src/plugin-qt/xsettings/plugin.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2025 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2025 - 2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: LGPL-3.0-or-later
 
@@ -13,10 +13,6 @@ extern "C" int DSMRegister(const char *name, void *data)
 {
 
     auto connection = reinterpret_cast<QDBusConnection *>(data);
-    if (connection->interface()->isServiceRegistered(name)) {
-        qWarning() << "DBus service already exists:" << name;
-        return 1;
-    }
     xSettings = new XSettings1();
 
     QDBusConnection::RegisterOptions opts = QDBusConnection::ExportAllSlots | QDBusConnection::ExportAllSignals | QDBusConnection::ExportAllProperties;