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#include "TraceFile.hpp"
#include <stdexcept>
#include <QDebug>
#include <QString>
#include <QFile>
#include <QTextStream>
#include <QMessageLogContext>
#include <QDateTime>
#include <QMutex>
#include <QMutexLocker>
#include "pimpl_impl.hpp"
namespace
{
QMutex lock;
}
class TraceFile::impl
{
public:
impl (QString const& trace_file_path);
~impl ();
// no copying
impl (impl const&) = delete;
impl& operator = (impl const&) = delete;
private:
// write Qt messages to the diagnostic log file
static void message_handler (QtMsgType type, QMessageLogContext const& context, QString const& msg);
QFile file_;
QTextStream stream_;
QTextStream * original_stream_;
QtMessageHandler original_handler_;
static QTextStream * current_stream_;
};
QTextStream * TraceFile::impl::current_stream_;
// delegate to implementation class
TraceFile::TraceFile (QString const& trace_file_path)
: m_ {trace_file_path}
{
}
TraceFile::~TraceFile ()
{
}
TraceFile::impl::impl (QString const& trace_file_path)
: file_ {trace_file_path}
, original_stream_ {current_stream_}
, original_handler_ {nullptr}
{
// if the log file is writeable; initialise diagnostic logging to it
// for append and hook up the Qt global message handler
if (file_.open (QFile::WriteOnly | QFile::Append | QFile::Text))
{
stream_.setDevice (&file_);
current_stream_ = &stream_;
original_handler_ = qInstallMessageHandler (message_handler);
}
}
TraceFile::impl::~impl ()
{
// unhook our message handler before the stream and file are destroyed
if (original_handler_)
{
qInstallMessageHandler (original_handler_);
}
current_stream_ = original_stream_; // revert to prior stream
}
// write Qt messages to the diagnostic log file
void TraceFile::impl::message_handler (QtMsgType type, QMessageLogContext const& context, QString const& msg)
{
char const * severity;
switch (type)
{
case QtDebugMsg:
severity = "Debug";
break;
case QtWarningMsg:
severity = "Warning";
break;
case QtFatalMsg:
severity = "Fatal";
break;
default:
severity = "Critical";
break;
}
{
// guard against multiple threads with overlapping messages
QMutexLocker guard (&lock);
Q_ASSERT_X (current_stream_, "TraceFile:message_handler", "no stream to write to");
*current_stream_
<< QDateTime::currentDateTimeUtc ().toString ("yyyy-MM-ddTHH:mm:ss.zzzZ")
<< '(' << context.file << ':' << context.line /* << ", " << context.function */ << ')'
<< severity << ": " << msg.trimmed () <<
#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
endl;
#else
Qt::endl;
#endif
}
if (QtFatalMsg == type)
{
throw std::runtime_error {"Fatal Qt Error"};
}
}
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