added local filtering of debug/high level messages

Author: sy-c

include/InfoLogger/InfoLogger.hxx

@@ -295,6 +295,26 @@ class InfoLogger
     return *this;
   }
 
+
+  /// Functions to define a local log filtering policy, to discard immediately any log message
+  /// matching criteria.
+  /// This allows an application to self-configure its verbosity.
+  /// Messages are dropped immediately in the process, they do not reach infoLoggerD.
+
+  /// Select discarding of messages with DEBUG severity.
+  /// parameter: 0 (default, debug messages kept) or 1 (debug messages discarded)
+  void filterDiscardDebug(bool enable);
+  
+  /// Select discarding of messages with higher levels.
+  /// parameter: level from which messages are discarded (bigger than or equal to this level).
+  /// Can be InfoLogger::undefinedMessageOption.level, to keep messages of all levels (default)
+  /// Messages with undefined level are never filtered out.
+  void filterDiscardLevel(int excludeLevel);
+
+  /// Reset defined filters.
+  /// All messages are then kept and handled normally.
+  void filterReset();
+  
   ///////////////////////
   /// internals
   ///////////////////////

src/InfoLogger.cxx

@@ -290,6 +290,9 @@ class InfoLogger::Impl
   int pipeStderr[2];                           // a pipe to redirect stderr to collecting thread
   std::unique_ptr<std::thread> redirectThread; // the thread handling the redirection
   bool redirectThreadShutdown;                 // flag to ask the thread to stop
+  
+  bool filterDiscardDebug = false;  // when set, messages with debug severity are dropped
+  int filterDiscardLevel = InfoLogger::undefinedMessageOption.level; // when set, messages with higher level (>=) are dropped
 };
 
 void InfoLogger::Impl::refreshDefaultMsg()
@@ -352,6 +355,16 @@ int InfoLogger::Impl::pushMessage(InfoLogger::Severity severity, const char* mes
 
 int InfoLogger::Impl::pushMessage(const InfoLoggerMessageOption& options, const InfoLoggerContext& context, const char* messageBody)
 {
+  // check if message passes local filter criteria, if any
+  if (filterDiscardDebug && (options.severity == InfoLogger::Severity::Debug)) {
+    return 1;
+  }
+  if ((filterDiscardLevel != undefinedMessageOption.level)
+       && (options.level != undefinedMessageOption.level)
+       && (options.level >= filterDiscardLevel)) {
+      return 1;
+  }
+  
   infoLog_msg_t msg = defaultMsg;
 
   struct timeval tv;
@@ -839,6 +852,21 @@ int InfoLogger::setStandardRedirection(bool state)
   return 0;
 }
 
+void InfoLogger::filterDiscardDebug(bool enable) {
+  mPimpl->filterDiscardDebug=enable;
+}
+
+void InfoLogger::filterDiscardLevel(int excludeLevel) {
+  mPimpl->filterDiscardLevel = excludeLevel;
+}
+
+void InfoLogger::filterReset() {
+  mPimpl->filterDiscardDebug = false;
+  mPimpl->filterDiscardLevel = InfoLogger::undefinedMessageOption.level;
+}
+
+
+
 // end of namespace
 } // namespace InfoLogger
 } // namespace AliceO2

test/testInfoLogger.cxx

@@ -58,5 +58,19 @@ int main()
 
   theLog.log(LogInfoDevel, "Test message with InfoLoggerMessageOption macro");
   theLog << LogInfoOps << "Test message with InfoLoggerMessageOption macro" << InfoLogger::endm;
+  
+  
+  // local filtering of messages  
+  theLog.log(LogInfoDevel, "Devel message without filter");
+  theLog.filterDiscardLevel(InfoLogger::Level::Devel);
+  theLog.log(LogInfoDevel, "Devel message with level filter - you should not see this");
+  theLog.filterReset();
+  theLog.log(LogInfoDevel, "Devel message with level filter reset - you should see this again");
+  theLog.log(LogDebugDevel, "Debug message without filter");
+  theLog.filterDiscardDebug(1);
+  theLog.log(LogDebugDevel, "Debug message with severity filter - you should not see this");
+  theLog.log(LogInfoDevel, "Info message with severity filter - you should see this");
+  theLog.filterReset();
+  theLog.log(LogDebugDevel, "Debug message with severity filter - you should see this again");
   return 0;
 }