log_system.c

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/******************************************************************************
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/**
 * @file log_system.c
 * @ingroup log_system
 * @author Jason Duffy
 * @date 1st March 2022
 * @brief Driver file providing logging functionality over USART, to print
 * debug messages and values to a teminal program on your PC. 
 * @bug No known bugs. 
 */
 
#include <stdbool.h>
 
#include "usart.h"
#include "log_system.h"
 
 
/**
 * Instantiation of log system config object, pass it's address into logging
 * functions. 
 */
log_system_config_t log_system_log =
{
  .p_system_tag = "Log_System",
  .file_log_level = INFO,
};
 
 
/**
 * Flag to determine whether logging output is turned on or off globally. The
 * flag itself however is at file scope only. 
 */
static bool log_system_enabled = false;
 
 
/**
 * Variable to store the preferred maximum level of logging with global effect.
 * Maximum level available by default. Call log_set_global_max_output_level()
 * to change this value.  
 */
static log_type_t global_max_output_level = VERBOSE_DEBUG;
 
 
// Forward declaration - private helper functions. 
void print_tag_and_log_level(const char *p_tag, log_type_t level);
bool log_message_preference_check(log_system_config_t *p_config,
                                  log_type_t level);
 
 
/*
 * Initialisation routine - call this function once at startup before using
 * other functions. Log system will then be turned on by default - call
 * log_global_off() if you do not wish it to be.
 */
void init_log_system(void)
{
  init_usart();
  log_global_on();
  log_message(&log_system_log, INFO, "Log system initialised");
};
 
 
/*
 * Sends only the system tag, log level and message string.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the level status of the log message - see log_type_t for
 * available options.
 * @param msg is the message to be logged, enclose it in "" quotation marks.
 */
void log_message(log_system_config_t *p_config,
                 log_type_t level,
                 const char *msg)
{
  // If all test expressions evaluate true, log message.
  if (log_message_preference_check(p_config, level))
  {
    print_tag_and_log_level(p_config->p_system_tag, level);
    usart_print_string(msg);
   }
}
 
 
/*
 * Sends a string, followed by an 8 bit value in decimal format.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the level status of the log message - see log_type_t for
 * available options.
 * @param msg is the message to be logged, enclose it in "" quotation marks.
 * @param val is the numerical value to be logged - Acceptable values 0 - 255.
 */
void log_message_with_dec_val(log_system_config_t *p_config,
                                 log_type_t level,
                                 const char *msg,
                                 uint8_t val)
{
  // If all test expressions evaluate true, log message.
  if (log_message_preference_check(p_config, level))
  {
    print_tag_and_log_level(p_config->p_system_tag, level);
    usart_print_string(msg);
    usart_print_string(" ");
    usart_print_byte(val); 
  }
}
 
/*
 * Sends a string, followed by a 16 bit value in decimal format.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the level status of the log message - see log_type_t for
 * available options.
 * @param msg is the message to be logged, enclose it in "" quotation marks.
 * @param val is the numerical value to be logged - Acceptable values 0 - 255.
 */
void log_message_with_dec_val(log_system_config_t *p_config,
                                 log_type_t level,
                                 const char *msg,
                                 uint8_t val)
{
  // If all test expressions evaluate true, log message.
  if (log_message_preference_check(p_config, level))
  {
    print_tag_and_log_level(p_config->p_system_tag, level);
    usart_print_string(msg);
    usart_print_string(" ");
    usart_print_byte(val); 
  }
}
 
 
/*
 * Sends a string, followed by an 8 bit value in binary format.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the level status of the log message - see log_type_t for
 * available options.
 * @param msg is the message to be logged, enclose it in "" quotation marks.
 * @param val is the numerical value to be logged - Acceptable values 0 - 255.
 */
void log_message_with_bin_val(log_system_config_t *p_config,
                              log_type_t level,
                              const char *msg,
                              uint8_t val)
{
  // If all test expressions evaluate true, log message.
  if (log_message_preference_check(p_config, level))
  {
    print_tag_and_log_level(p_config->p_system_tag, level);
    usart_print_string(msg);
    usart_print_string(" ");
    usart_print_binary_byte(val);
  }
}
 
 
/*
 * Sends a string, followed by an 8 bit value in hexadecimal format.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the level status of the log message - see log_type_t for
 * available options.
 * @param msg is the message to be logged, enclose it in "" quotation marks.
 * @param val is the numerical value to be logged - Acceptable values 0 - 255.
 */
void log_message_with_hex_val(log_system_config_t *p_config,
                              log_type_t level,
                              const char *msg,
                              uint8_t val)
{
  // If all test expressions evaluate true, log message.
  if (log_message_preference_check(p_config, level))
  {
    print_tag_and_log_level(p_config->p_system_tag, level);
    usart_print_string(msg);
    usart_print_string(" ");
    usart_print_hex_byte(val);
  }
}
 
 
/*
 * Sets maximum output level of logging required, to be used at file scope.
 * @param p_config is a pointer to the log_system config object. Instantiate
 * the config object at the head of each file where logging is required and
 * pass it's address into this function.
 * @param level is the maximum level required - see log_type_t for available
 * options.
 */
void log_set_file_max_output_level(log_system_config_t *p_config,
                                   log_type_t level)
{
  p_config->file_log_level = level;
}
 
 
/*
 * Sets maximum output level of logging required, has global effect.
 * @param level is the maximum level required - see log_type_t for available
 * options.
 */
void log_set_global_max_output_level(log_type_t level)
{
  global_max_output_level = level;
}
 
 
/*
 * Turns logging system on globally.
 */
void log_global_on(void)
{
  log_system_enabled = true;
}
 
 
/*
 * Turns logging system off globally.
 */
void log_global_off(void)
{
  log_system_enabled = false;
}
 
 
// ------------------------------------------------------------------------- //
// ------------------------ Private Helper Functions ----------------------- //
// ------------------------------------------------------------------------- //
 
/**
 * Utility function to print labels over serial.
 */
void print_tag_and_log_level(const char *p_tag, log_type_t level)
{
  if (level == NONE)
  {
 
  }
  usart_print_string("\n");
  usart_print_string(p_tag);
 
  if (level == ERROR)
  {
    usart_print_string(", ERROR: ");
  }
 
  else if (level == WARNING)
  {
    usart_print_string(", WARNING: ");
  }
 
  else if (level == INFO)
  {
    usart_print_string(", INFO: ");
  }
 
  else if (level == DEBUG)
  {
    usart_print_string(", DEBUG: ");
  }
 
  else if (level == VERBOSE_DEBUG)
  {
    usart_print_string(", VERBOSE_DEBUG: ");
  }
 
  else
  {
    usart_print_string(", INVALID_LOG_LEVEL: ");
  }
}
 
 
/**
 * Utility function to test if the log message level meets the preferences set.
 */
bool log_message_preference_check(log_system_config_t *p_config,
                                  log_type_t level)
{
  // Test if log_system is enabled globally, if not then do nothing. 
  if (log_system_enabled)
  {
    // Test if the level of this log message meets global log preferences. 
    if (level <= global_max_output_level)
    {
      // Test if the level of this log message meets file level preferences.
      if (level <= p_config->file_log_level)
      {
        return true;
      }
    }
  }
  // If any of the above conditionals evaluate to false, return false. 
  return false;
}
 
/*** end of file ***/