Use common formatter for console and file sinks

The severity level of the file sink is now set to trace so that
it logs to file regardless of the severity level of the console.

This patch also adds an API to set the severity level of just the
console sink.

Signed-off-by: Addisu Z. Taddese <addisu@openrobotics.org>

log/include/gz/utils/log/Logger.hh

@@ -57,6 +57,10 @@ class GZ_UTILS_LOG_VISIBLE Logger
   /// \return The spdlog logger.
   public: [[nodiscard]] std::shared_ptr<spdlog::logger> RawLoggerPtr() const;
 
+  /// \brief Set the severity level of the Console sink
+  /// \param [in] _level Severity level
+  public: void SetConsoleSinkLevel(spdlog::level::level_enum _level);
+
   /// \brief Implementation Pointer.
   GZ_UTILS_UNIQUE_IMPL_PTR(dataPtr)
 };

log/src/Logger.cc

@@ -25,6 +25,11 @@
 
 namespace gz::utils::log
 {
+namespace {
+  /// \brief Default log format
+  /// Example output
+  constexpr std::string_view kDefaultLogFormat{"%^(%Y-%m-%d %T.%e) [%l] %v%$"};
+}
 /// \brief Private data for the Logger class.
 class Logger::Implementation
 {
@@ -33,6 +38,9 @@ class Logger::Implementation
   public: explicit Implementation(const std::string &_loggerName)
     : consoleSink(std::make_shared<SplitConsoleSink>()),
       sinks(std::make_shared<spdlog::sinks::dist_sink_mt>()),
+      formatter(std::make_unique<spdlog::pattern_formatter>(
+            kDefaultLogFormat.data(),
+            spdlog::pattern_time_type::local, std::string(""))),
       logger(std::make_shared<spdlog::logger>(_loggerName, sinks))
   {
   }
@@ -46,6 +54,9 @@ class Logger::Implementation
   /// \brief A sink distribution storing multiple sinks.
   std::shared_ptr<spdlog::sinks::dist_sink_mt> sinks {nullptr};
 
+  /// \brief Common formatter for both all sinks
+  std::unique_ptr<spdlog::pattern_formatter> formatter;
+
   /// \brief The underlying spdlog logger.
   std::shared_ptr<spdlog::logger> logger {nullptr};
 };
@@ -58,13 +69,10 @@ Logger::Logger(const std::string &_loggerName)
   this->dataPtr->sinks->add_sink(this->dataPtr->consoleSink);
 
   // Configure the logger.
-  this->dataPtr->logger->set_level(spdlog::level::err);
+  this->dataPtr->consoleSink->set_level(spdlog::level::err);
   this->dataPtr->logger->flush_on(spdlog::level::err);
 
-  // Disable eol.
-  auto f = std::make_unique<spdlog::pattern_formatter>(
-    "%+", spdlog::pattern_time_type::local, std::string(""));
-  this->dataPtr->logger->set_formatter(std::move(f));
+  this->dataPtr->logger->set_formatter(this->dataPtr->formatter->clone());
 }
 
 /////////////////////////////////////////////////
@@ -77,6 +85,8 @@ void Logger::SetLogDestination(const std::string &_filename)
   {
     this->dataPtr->fileSink =
       std::make_shared<spdlog::sinks::basic_file_sink_mt>(_filename, true);
+    this->dataPtr->fileSink->set_formatter(this->dataPtr->formatter->clone());
+    this->dataPtr->fileSink->set_level(spdlog::level::trace);
     this->dataPtr->sinks->add_sink(this->dataPtr->fileSink);
   }
 }
@@ -103,4 +113,13 @@ std::shared_ptr<spdlog::logger> Logger::RawLoggerPtr() const
   return this->dataPtr->logger;
 }
 
+/////////////////////////////////////////////////
+void Logger::SetConsoleSinkLevel(spdlog::level::level_enum _level)
+{
+  if (this->dataPtr->consoleSink)
+  {
+    this->dataPtr->consoleSink->set_level(_level);
+  }
+}
+
 }  // namespace gz::utils::log