New handling for debug and status information

Question

Issue by frickler24 Tuesday Apr 11, 2017 at 20:31 GMT Originally opened as https://github.com/mattanger/ckb-next/issues/149

This is follower of #147 as recommended

I did some experiments with qDebug. Since Qt 5.6 they implemented a verbosity-flag. Now you can - decide which function you use (qDebug, qWarning, qCritical, qFatal) - give a verbosity information with it:

qDebug().setVerbosity(7) << "This is a very critical issue and should be displayed in any case!";
qDebug().setVerbosity(0) << "If a user wants to read this stuff, he may select this.";

Standard Qt verbosity is 2. In the next days I will post a skeleton how I think we may use this. Like this article describes some aspects of it. Or has someone experience with it?

该提问来源于开源项目：ckb-next/ckb-next

Answer 1

Comment by frickler24 Wednesday Apr 12, 2017 at 09:00 GMT

Following the article mentioned above, I played a bit with QDebug class. Standard function is to decide between 5 modes: - qFatal() is used if you cannot do anything more than exiting. This method needs a special handler and I think we should not use it, because of handling notify-channels etc. - qCritical() is for really critical situations (eg unknown usb events, closed pipes, no more memory, SIGSEGV and so on). I Think we have some error-handling in the code (some handling may be anhanced :-)) to use this mode. - qWarning() is less than critical and may be used if we could not load new firmware etc. - qInfo() is less again and might be used for messages like our standard message "Downloaded new firmware list. 12 entries found." - qDebug() should be used for debugging only. Here we can produce lots of raw data for our purposes.

The handling of these modes is easy and brings a second option: More info about the source of the message. If we run "make" a Qt-Parameter QT_NO_DEBUG is set - if we run "make debug" it is not set. We can use this to generate shorter or longer debug info. As a first implementation I added filename, lineno and function-name in the long part. Then I added a CLI parameter -d / --debuglevel \<num> To be compatible with the value range of the verbosity in Qt in general, I created 8 debug-modes (0..7):

/// \brief debugLevel controls the amount of debug output.
///     0 = no debug output, just hard errors (Fatal) are displayed in a short form
///     1 = no debug output, just hard errors (Fatal) are displayed in a long form
///     2 = Error-handling and inconsistencies (Fatal + Critical = default value) in short form
///     3 = as 2 but in long form
///     4 = as 2 + Warnings (in short form)
///     5 = as 4 but in long form
///     6 = All info, but no debug data (eg logging from usb) in short form
///     7 = full debug output with complete logging runtime data (eg logging from usb) in long form

By adding one test-message per mode to main (), you get the following amount of information - depending on the debug level:

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d0
DebugLevel is set to 0

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d1
DebugLevel is set to 1

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d2
DebugLevel is set to 2
Critical: Critical messages are shown

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d3
DebugLevel is set to 3
Critical: Critical messages are shown (main.cpp:319, int main(int, char**))

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d4
DebugLevel is set to 4
Warning: Warnings are shown
Critical: Critical messages are shown

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d5
DebugLevel is set to 5
Warning: Warnings are shown (main.cpp:318, int main(int, char**))
Critical: Critical messages are shown (main.cpp:319, int main(int, char**))

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d6
DebugLevel is set to 6
Info: Info messages are shown
Warning: Warnings are shown
Critical: Critical messages are shown

lutz ~/Projekte/ckb-next/src/ckb $ ../../bin/ckb -d7
DebugLevel is set to 7
Debug: Debug messages are shown (main.cpp:316, int main(int, char**))
Info: Info messages are shown (main.cpp:317, int main(int, char**))
Warning: Warnings are shown (main.cpp:318, int main(int, char**))
Critical: Critical messages are shown (main.cpp:319, int main(int, char**))
Debug: Scanning  "/usr/lib/ckb-animations/ckb-gradient" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-heat" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-mviz" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-pinwheel" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-rain" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-random" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-ripple" (animscript.cpp:81, bool AnimScript::load())
Debug: Scanning  "/usr/lib/ckb-animations/ckb-wave" (animscript.cpp:81, bool AnimScript::load())
Debug: Starting  "/usr/lib/ckb-animations/ckb-gradient" (animscript.cpp:315, void AnimScript::begin(quint64))
Debug: Downloaded new firmware list. 12 entries found. (kbfirmware.cpp:141, void KbFirmware::processDownload(QNetworkReply*))

Any comments on this?