modularize logging code and redo runtime logging method switching

src/logging.cc

@@ -0,0 +1,75 @@
+#include "config.hh"
+#include "logging.hh"
+#include <QGlobalStatic>
+#include <QMutexLocker>
+#include <QDateTime>
+
+Q_GLOBAL_STATIC(Logger, gd_logger)
+
+QMutex logMutex;
+
+void logToFileMessageHander( QtMsgType type, const QMessageLogContext & context, const QString & mess )
+{
+  QString strTime = QDateTime::currentDateTime().toString( "MM-dd hh:mm:ss" );
+  QString message = QString( "%1 %2\r\n" ).arg( strTime, mess );
+
+  if ( gd_logger -> logFile.isOpen() ) {
+    //without the lock ,on multithread,there would be assert error.
+    QMutexLocker _( &logMutex );
+    switch ( type ) {
+      case QtDebugMsg:
+        message.prepend( "Debug: " );
+      break;
+      case QtWarningMsg:
+        message.prepend("Warning: " );
+      break;
+      case QtCriticalMsg:
+        message.prepend( "Critical: " );
+      break;
+      case QtFatalMsg:
+        message.prepend( "Fatal: " );
+      gd_logger -> logFile.write( message.toUtf8() );
+      gd_logger -> logFile.flush();
+      abort();
+      case QtInfoMsg:
+        message.insert( 0, "Info: " );
+      break;
+    }
+
+    gd_logger -> logFile.write( message.toUtf8() );
+    gd_logger -> logFile.flush();
+
+    return;
+  } else {
+    throw std::runtime_error( "logToFileMessageHandler fatal error!" );
+  }
+}
+
+void Logger::retainDefaultMessageHandler(QtMessageHandler handler){
+  gd_logger->defaultMessageHandler=handler;
+}
+
+void Logger::switchLoggingMethod(bool logToFile){
+  if(logToFile){
+    if(!gd_logger -> logFile.isOpen()){
+      gd_logger -> logFile.setFileName( Config::getConfigDir() + "gd_log.txt" );
+      if(!gd_logger -> logFile.open( QFile::WriteOnly )){
+         qDebug()<<"Failed to open log file!";
+        return;
+      };
+    }
+    qInstallMessageHandler(logToFileMessageHander);
+  } else {
+    if(gd_logger -> logFile.isOpen()){
+      gd_logger -> logFile.flush();
+    }
+    qInstallMessageHandler(gd_logger->defaultMessageHandler);
+  }
+}
+
+void Logger::closeLogFile(){
+  if(gd_logger -> logFile.isOpen()){
+    gd_logger -> logFile.flush();
+    gd_logger -> logFile.close();
+  }
+}

src/logging.hh

@@ -0,0 +1,12 @@
+#pragma once
+#include <QFile>
+#include <QMutex>
+
+/// Manage Logging, mainly for switching to log-to-file because of Windows
+struct Logging {
+    static void retainDefaultMessageHandler(QtMessageHandler);
+    static void switchLoggingMethod( bool logToFile );
+    static void closeLogFile();
+    QFile logFile;
+    QtMessageHandler defaultMessageHandler;
+};

src/main.cc

@@ -2,7 +2,7 @@
  * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
 
 #include "config.hh"
-#include "logfileptr.hh"
+#include "logging.hh"
 #include "mainwindow.hh"
 #include "termination.hh"
 #include "version.hh"
@@ -14,11 +14,9 @@
 #include <QMutex>
 #include <QSessionManager>
 #include <QString>
-#include <QStringBuilder>
 #include <QtWebEngineCore/QWebEngineUrlScheme>
 #include <stdio.h>
 #include <QStyleFactory>
-
 #if defined( Q_OS_UNIX )
   #include <clocale>
   #include "unix/ksignalhandler.hh"
@@ -82,66 +80,6 @@ bool callback( const char * dump_dir, const char * minidump_id, void * context,
   #endif
 #endif
 
-QMutex logMutex;
-
-void gdMessageHandler( QtMsgType type, const QMessageLogContext & context, const QString & mess )
-{
-  if ( GlobalBroadcaster::instance()->getPreference() == nullptr
-       || !GlobalBroadcaster::instance()->getPreference()->enableApplicationLog ) {
-    return;
-  }
-  QString strTime = QDateTime::currentDateTime().toString( "MM-dd hh:mm:ss" );
-  QString message = QString( "%1 %2\r\n" ).arg( strTime, mess );
-
-  if ( ( logFilePtr != nullptr ) && logFilePtr->isOpen() ) {
-    //without the lock ,on multithread,there would be assert error.
-    QMutexLocker _( &logMutex );
-    switch ( type ) {
-      case QtDebugMsg:
-        message.insert( 0, "Debug: " );
-        break;
-      case QtWarningMsg:
-        message.insert( 0, "Warning: " );
-        break;
-      case QtCriticalMsg:
-        message.insert( 0, "Critical: " );
-        break;
-      case QtFatalMsg:
-        message.insert( 0, "Fatal: " );
-        logFilePtr->write( message.toUtf8() );
-        logFilePtr->flush();
-        abort();
-      case QtInfoMsg:
-        message.insert( 0, "Info: " );
-        break;
-    }
-
-    logFilePtr->write( message.toUtf8() );
-    logFilePtr->flush();
-
-    return;
-  }
-
-  //the following code lines actually will have no chance to run, schedule to remove in the future.
-  QByteArray msg = mess.toUtf8().constData();
-  switch ( type ) {
-    case QtDebugMsg:
-      fprintf( stderr, "Debug: %s\n", msg.constData() );
-      break;
-    case QtWarningMsg:
-      fprintf( stderr, "Warning: %s\n", msg.constData() );
-      break;
-    case QtCriticalMsg:
-      fprintf( stderr, "Critical: %s\n", msg.constData() );
-      break;
-    case QtFatalMsg:
-      fprintf( stderr, "Fatal: %s\n", msg.constData() );
-      abort();
-    case QtInfoMsg:
-      fprintf( stderr, "Info: %s\n", msg.constData() );
-      break;
-  }
-}
 
 struct GDOptions
 {
@@ -426,15 +364,6 @@ int main( int argc, char ** argv )
     QWebEngineUrlScheme::registerScheme( webUiScheme );
   }
 
-  QFile file;
-  logFilePtr = &file;
-  auto guard = qScopeGuard( [ &file ]() {
-    logFilePtr = nullptr;
-    file.close();
-  } );
-
-  Q_UNUSED( guard )
-
   QFont f = QApplication::font();
   f.setStyleStrategy( QFont::PreferAntialias );
   QApplication::setFont( f );
@@ -518,12 +447,10 @@ int main( int argc, char ** argv )
 
   cfg.resetState = gdcl.resetState;
 
+  Logging::retainDefaultMessageHandler( qInstallMessageHandler( nullptr ) );
+
   // Log to file enabled through command line or preference
-  if ( gdcl.logFile || cfg.preferences.enableApplicationLog ) {
-    logFilePtr->setFileName( Config::getConfigDir() + "gd_log.txt" );
-    logFilePtr->open( QFile::WriteOnly );
-    qInstallMessageHandler( gdMessageHandler );
-  }
+  Logging::switchLoggingMethod( gdcl.logFile || cfg.preferences.enableApplicationLog );
 
   // Reload translations for user selected locale is nesessary
   QTranslator qtTranslator;
@@ -622,9 +549,5 @@ int main( int argc, char ** argv )
 #endif
   int r = app.exec();
 
-  if ( logFilePtr->isOpen() ) {
-    logFilePtr->close();
-  }
-
   return r;
 }

src/termination.cc

@@ -2,19 +2,15 @@
 /* This file is (c) 2008-2012 Konstantin Isakov <[email protected]>
  * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
 
-#include "logfileptr.hh"
+#include "log_to_file.hh"
 #include "termination.hh"
 #include <QDebug>
 #include <exception>
 
 static void termHandler()
 {
   qDebug() << "GoldenDict has crashed unexpectedly.\n\n";
-
-  if ( logFilePtr && logFilePtr->isOpen() ) {
-    logFilePtr->close();
-  }
-
+  Logger::closeLogFile();
   abort();
 }
 

src/ui/mainwindow.cc

@@ -8,6 +8,7 @@
 #endif
 
 #include "mainwindow.hh"
+#include "logging.hh"
 #include <QWebEngineProfile>
 #include "edit_dictionaries.hh"
 #include "dict/loaddictionaries.hh"
@@ -2366,6 +2367,8 @@ void MainWindow::editPreferences()
 
     ui.fullTextSearchAction->setEnabled( cfg.preferences.fts.enabled );
 
+    Logging::switchLoggingMethod( cfg.preferences.enableApplicationLog );
+
     Config::save( cfg );
   }