Class vart::Logger#

class Logger#

The logger module provides the logging support for VART modules.

Supports logging to console, file, syslog.

Public Functions

std::shared_ptr<struct log_context> mod_register(const char *modname, bool need_id)#

mod_register() - Registers a module with logger object

If the module is already registered with the logger, its instance id is incremented, else a default instance id = 0 is assigned. Module instance log level is assigned from logger object’s database or from global log level if per module log level is not provided by user. If need_id is set to false, module instance id is not appended to module’s instance name. Components such as ‘videoframe’, ‘memory’ need to set this flag to false as there can be too many instances of those components in a single pipeline use case and can be be distinguished by their pointers. Components representing IP blocks can set this to true to distinguish IP instances.

Parameters:

  • modname – Module name to register with logger

  • need_id – Flag describing the need for an id to be appended to module name during logging

Returns:

Returns logger context associated with a module instance.

void vart_logger_log_obj(LogLevel, std::shared_ptr<struct log_context> ctx, const char *filename, const char *func, uint32_t line, const char *fmt, ...)#

vart_logger_log_obj() - Logs a module’s message along with metadata like filename, function name, line number, process id, thread id.

Parameters:

  • LogLevel – Logging level with which module logs a message

  • ctx – Module’s logger context obtained with mod_register()

  • filename – Source code filename from which this logging is triggered

  • func – Source code function name

  • line – Source code line number

  • fmt – Format string passed for logging.

Public Static Functions

static inline Logger &get_instance()#

get_instance() - Creates a logger() instance if not created earlier, else return an existing instance.

Logger object when created reads the environment variable VART_CORE_DEBUG to get and store log levels of each module and global log level. Default module instance id is stored as -1. This id will be updated later when each module instance registers with logger. Apart from that, logger reads the environment variable VART_LOG_FILE_PATH and if:

  1. VART_LOG_FILE_PATH is set to CONSOLE, logs messages to on screen console.

  2. VART_LOG_FILE_PATH is set to SYSLOG, appends log messages to syslog.

  3. VART_LOG_FILE_PATH is set to a file on disk, log messages to that file. If the file cannot be opened to log, defaults to syslog logging.

Returns:

Returns a logger instance

Private Functions

Logger()#
~Logger()#
Logger(const Logger&) = delete#
void operator=(const Logger&) = delete#

Private Members

LogLevel global_log_level#
LogLevel level#
LogType type#
std::mutex reg_mutex#
std::mutex log_mutex#
std::map<std::string, std::tuple<int16_t, uint16_t>> vart_components#
std::chrono::high_resolution_clock::time_point logger_start_time#
std::FILE *log_file#