Added a quill::get_handler(handler_name) function that allows easy lookup of an existing Handler by name. This function proves helpful when you want to retrieve a handler and pass it to a new logger.

Fix build failure of Intel Compiler Classic. (#332)

Introduced QUILL_BLOCKING_QUEUE_RETRY_INTERVAL_NS option for user-configurable retry interval in the blocking queue. Default value is 800 nanoseconds. (#330)

Improved backend thread handling. Now verifies that all producer SPSC queues are empty before entering sleep.

Fixed a race condition and potential crash in quill::remove_logger(Logger*) when called without prior quill::flush().

Added protection to prevent removal of the root logger with quill::remove_logger(Logger*).

Improved exception handling on the backend thread when calling fmt::format().

While compile-time checks ensure that the format string and arguments match, runtime errors can still occur. Previously, such exceptions would affect and drop subsequent log records. Now, exceptions are caught and logged in the log file and reported via the backend thread notification handler (default is cerr).

For example, if a dynamic precision is used (LOG_INFO(logger, "Support for floats {:.{}f}", 1.23456, 3.321312)), the log file will show the following error message:

LOG_INFO root [format: "Support for floats {:.{}f}", error: "precision is not integer"]

Additionally, an error message will be printed to cerr

Quill ERROR: [format: "Support for floats {:.{}f}", error: "precision is not integer"]

Fixed a bug in timestamp formatting that occasionally displayed an hour component of 0 as 24. (#329)

Added support for specifying a runtime log level, allowing dynamic log level configuration at runtime. The new runtime log level feature provides flexibility when needed, with a minor overhead cost. It is recommended to continue using the existing static log level macros for optimal performance. (#321)

For example

  std::array<quill::LogLevel, 4> const runtime_log_levels = {quill::LogLevel::Debug,
                                                             quill::LogLevel::Info,
                                                             quill::LogLevel::Warning,
                                                             quill::LogLevel::Error};

  for (auto const& log_level : runtime_log_levels)
  {
    LOG_DYNAMIC(logger, log_level, "Runtime {} {}", "log", "level");
  }

Added support for printf-style formatting with _CFORMAT macros. These macros use the printf format string syntax, simplifying the migration of legacy codebases using printf statements.

For example

  std::array<uint32_t, 4> arr = {1, 2, 3, 4};
  LOG_INFO(logger, "This is a log info example using fmt format {}", arr);

  LOG_INFO_CFORMAT(logger, "printf style %s supported %d %f", "also", 5, 2.32);

Added a metadata() member function to the TransitEvent class. It provides access to the Metadata object associated with the log record, simplifying syntax for retrieving log record metadata in custom Handlers.

For example

void CustomHandler::write(fmt_buffer_t const& formatted_log_message, quill::TransitEvent const& log_event)
{
  MacroMetadata const macro_metadata = log_event.metadata();
}

Simplified file handler configuration. Now, instead of passing multiple arguments to the constructor, you only need to provide a single FileHandlerConfig object. This change makes creating file handlers objects much easier and more flexible.

For example

quill::FileHandlerConfig file_handler_cfg;
file_handler_cfg.set_open_mode('w');
file_handler_cfg.set_append_to_filename(quill::FilenameAppend::StartDateTime);

std::shared_ptr<quill::Handler> file_handler = quill::file_handler("application.log", file_handler_cfg);
quill::Logger* logger_foo = quill::create_logger("my_logger", std::move(file_handler));

LOG_INFO(my_logger, "Hello from {}", "application");

Combined the functionalities of RotatingFileHandler (rotating based on file size) and TimeRotatingFileHandler (rotating on a time interval) into a single, more versatile RotatingFileHandler. Users can now conveniently rotate logs based on both file size and time intervals simultaneously. The updated RotatingFileHandler offers a variety of customization options for improved flexibility. For more information on available configurations, refer to the RotatingFileHandlerConfig documentation.

For example

  // Create a rotating file handler which rotates daily at 18:30 or when the file size reaches 2GB
std::shared_ptr<quill::Handler> file_handler =
  quill::rotating_file_handler(filename,
                               []()
                               {
                                 quill::RotatingFileHandlerConfig cfg;
                                 cfg.set_rotation_time_daily("18:30");
                                 cfg.set_rotation_max_file_size(2'000'000'000);
                                 return cfg;
                               }());

// Create a logger using this handler
quill::Logger* logger_bar = quill::create_logger("daily_logger", std::move(file_handler));

Improved compatibility with older versions of external libfmt. Quill now compiles for all versions of libfmt >= 8.0.0.