refact: optimize regular expression initialization

add profiling test.

Signed-off-by: ComixHe <heyuming@deepin.org>

CMakeLists.txt

@@ -15,6 +15,7 @@ set(THREADS_PREFER_PTHREAD_FLAG ON)
 
 set(BUILD_EXAMPLES ON CACHE BOOL "Whether to build examples or not.")
 set(DEBUG_MODE ON CACHE BOOL "start a dde-applicatiom-manager service for debug")
+set(PROFILING_MODE OFF CACHE BOOL "run a valgrind performance profiling.")
 
 find_package(Qt6 REQUIRED COMPONENTS Core DBus Concurrent)
 find_package(Threads REQUIRED)
@@ -25,6 +26,10 @@ if(DEBUG_MODE)
     add_compile_definitions(-DDEBUG_MODE)
 endif()
 
+if(PROFILING_MODE)
+    add_compile_definitions(-DDPROFILING_MODE)
+endif()
+
 add_subdirectory(src)
 add_subdirectory(plugins)
 add_subdirectory(apps)

apps/dde-application-manager/src/main.cpp

@@ -8,6 +8,10 @@
 #include <QDir>
 #include "dbus/applicationmanager1service.h"
 #include "cgroupsidentifier.h"
+#include <chrono>
+#include <iostream>
+
+Q_LOGGING_CATEGORY(DDEAMProf, "dde.am.prof", QtInfoMsg)
 
 namespace {
 void registerComplexDbusType()
@@ -21,6 +25,7 @@ void registerComplexDbusType()
 
 int main(int argc, char *argv[])
 {
+    auto start = std::chrono::high_resolution_clock::now();
     QCoreApplication app{argc, argv};
 
     auto &bus = ApplicationManager1DBus::instance();
@@ -43,6 +48,12 @@ int main(int argc, char *argv[])
         AMService.addApplication(std::move(ret).value());
         return false;  // means to apply this function to the rest of the files
     });
-
+    auto end = std::chrono::high_resolution_clock::now();
-    return QCoreApplication::exec();
+    qCInfo(DDEAMProf) << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count() << "ms";
+    return
+#ifdef PROFILING_MODE
+        QCoreApplication::exec();
+#else
+        0;
+#endif
 }

src/desktopentry.cpp

@@ -59,8 +59,12 @@ DesktopErrorCode DesktopEntry::parseEntry(const QString &str, decltype(m_entryMa
     const static auto validKey =
         QString("^%1(?:\\[(?<LOCALE>%2%3?%4?%5?)\\])?$").arg(MainKey).arg(Language).arg(Country).arg(Encoding).arg(Modifier);
     // example: https://regex101.com/r/hylOay/1
-    QRegularExpression re{validKey};
+    static QRegularExpression re = []() -> QRegularExpression {
-    re.optimize();
+        QRegularExpression tmp{validKey};
+        tmp.optimize();
+        return tmp;
+    }();
+
     auto matcher = re.match(keyStr);
     if (!matcher.hasMatch()) {
 #ifdef DEBUG_MODE
@@ -216,8 +220,8 @@ DesktopErrorCode DesktopEntry::parse(QTextStream &stream) noexcept
             continue;
         }
 
-        if (line.startsWith("[")) {
+        if (line[0] == '[') {
-            if (!line.endsWith("]")) {
+            if (!(line[line.size() - 1] == ']')) {
                 return DesktopErrorCode::GroupHeaderInvalid;
             }
             currentGroup = parserGroupHeader(line);

src/global.h

@@ -19,10 +19,13 @@
 #include <QDBusObjectPath>
 #include <unistd.h>
 #include <QUuid>
+#include <QLoggingCategory>
 #include <sys/stat.h>
 #include "constant.h"
 #include "config.h"
 
+Q_DECLARE_LOGGING_CATEGORY(DDEAMProf)
+
 using IconMap = QMap<QString, QMap<uint, QMap<QString, QDBusUnixFileDescriptor>>>;
 using ObjectMap = QMap<QDBusObjectPath, QStringList>;
 

tools/profiling.sh

@@ -0,0 +1,20 @@
+#!/bin/env bash
+
+# SPDX-FileCopyrightText: 2023 UnionTech Software Technology Co., Ltd.
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+cd "$(git rev-parse --show-toplevel)" || exit 255
+
+BUILD_DIR=${BUILD_DIR:="build-prof"}
+
+cmake -B "$BUILD_DIR" \
+    -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+    -DDEBUG_MODE=OFF \
+    -DPROFILING_MODE=ON
+
+cmake --build "$BUILD_DIR" -j$(nproc)
+
+QT_LOGGING_RULES="*.debug=false;*.info=false;*.warning=false" valgrind --tool=cachegrind --cachegrind-out-file="$BUILD_DIR/profiling.out" "$BUILD_DIR/apps/dde-application-manager/src/dde-application-manager"
+
+echo "you can use Kcachegrind to check this profiling result."

tools/test-coverage.sh

@@ -21,4 +21,4 @@ cmake --build "$BUILD_DIR" -j$(nproc)
 
 cmake --build "$BUILD_DIR" -j$(nproc) -t test
 
-gcovr -f "src/*" --html-details "$BUILD_DIR"/coverage.html
+gcovr -f "src/*" --html-details "$HTML_DIR"/coverage.html