logs.h

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/*
 * SPDX-FileCopyrightText: 2024-2025 Rafael V. Volkmer
 * SPDX-FileCopyrightText: <rafael.v.volkmer@gmail.com>
 * SPDX-License-Identifier: MIT
 */
 
#pragma once
 
/* < C++ Compatibility > */
#ifdef __cplusplus
extern "C"
{
#endif
 
/*< Dependencies >*/
#include <errno.h>
#include <pthread.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
 
typedef enum LogLevel
{
  LOG_LEVEL_NONE    = (uint8_t)(0u), 
  LOG_LEVEL_ERROR   = (uint8_t)(1u), 
  LOG_LEVEL_WARNING = (uint8_t)(2u), 
  LOG_LEVEL_INFO    = (uint8_t)(3u), 
  LOG_LEVEL_DEBUG   = (uint8_t)(4u)  
} log_level_t;
 
#ifndef LOG_LEVEL
  #define LOG_LEVEL LOG_LEVEL_DEBUG
#endif
 
#ifndef _POSIX_C_SOURCE
  #define _POSIX_C_SOURCE 200809UL
#endif
 
#if defined(__has_builtin)
  #if __has_builtin(__builtin_fprintf)
    #define LOG_PRINTF(...) __builtin_fprintf(__VA_ARGS__)
  #else
    #define LOG_PRINTF(...) fprintf(__VA_ARGS__)
  #endif
#else
  #if defined(__GNUC__)
    #define LOG_PRINTF(...) __builtin_fprintf(__VA_ARGS__)
  #else
    #define LOG_PRINTF(...) fprintf(__VA_ARGS__)
  #endif
#endif
 
#if defined(__has_builtin)
  #if __has_builtin(__builtin_vfprintf)
    #define LOG_VPRINTF(...) __builtin_vfprintf(__VA_ARGS__)
  #else
    #define LOG_VPRINTF(...) vfprintf(__VA_ARGS__)
  #endif
#else
  #if defined(__GNUC__)
    #define LOG_VPRINTF(...) __builtin_vfprintf(__VA_ARGS__)
  #else
    #define LOG_VPRINTF(...) vfprintf(__VA_ARGS__)
  #endif
#endif
 
#define PREFIX_ERROR   "[ERROR]"
#define PREFIX_WARNING "[WARNING]"
#define PREFIX_INFO    "[INFO]"
#define PREFIX_DEBUG   "[DEBUG]"
 
#define COLOR_RED      "\033[0;31m"
#define COLOR_YELLOW   "\033[0;33m"
#define COLOR_BLUE     "\033[0;34m"
#define COLOR_GREEN    "\033[0;32m"
#define COLOR_RESET    "\033[0m"
 
#ifndef ATTR_PRINTF
  #if defined(__has_attribute)
    #if __has_attribute(format)
      #define ATTR_PRINTF(fmt_idx, var_idx) \
        __attribute__((format(printf, fmt_idx, var_idx)))
    #else
      #define ATTR_PRINTF(fmt_idx, var_idx)
    #endif
  #elif defined(__GNUC__)
    #define ATTR_PRINTF(fmt_idx, var_idx) \
      __attribute__((format(printf, fmt_idx, var_idx)))
  #else
    #define ATTR_PRINTF(fmt_idx, var_idx)
  #endif
#endif
 
static inline int LOG_output(log_level_t level,
                             const char *color,
                             const char *prefix,
                             const char *file,
                             const char *func,
                             int         line,
                             const char *fmt,
                             ...) ATTR_PRINTF(7, 8);
 
static inline int LOG_output(log_level_t level,
                             const char *color,
                             const char *prefix,
                             const char *file,
                             const char *func,
                             int         line,
                             const char *fmt,
                             ...)
{
  int ret = EXIT_SUCCESS;
 
  FILE *out = (FILE *)NULL;
 
  static pthread_mutex_t log_mutex = PTHREAD_MUTEX_INITIALIZER;
 
  struct timespec ts;
  struct tm      *ptm = (struct tm *)NULL;
 
  time_t now = 0;
 
  long msec = 0u;
 
  if (level > LOG_LEVEL)
  {
    ret = -EIO;
    goto function_output;
  }
 
  pthread_mutex_lock(&log_mutex);
 
  memset(&ts, 0, sizeof(ts));
 
  clock_gettime(CLOCK_REALTIME, &ts);
 
  now = ts.tv_sec;
  ptm = localtime(&now);
 
  out  = (level <= LOG_LEVEL_WARNING) ? stderr : stdout;
  msec = ts.tv_nsec / 1000000L;
 
  LOG_PRINTF(out,
             "[%02d:%02d:%02d.%03ld] ",
             ptm->tm_hour,
             ptm->tm_min,
             ptm->tm_sec,
             msec);
 
  if (isatty(fileno(out)))
    LOG_PRINTF(out, "%s%s%s ", color, prefix, COLOR_RESET);
  else
    LOG_PRINTF(out, "%s ", prefix);
 
  va_list args;
  va_start(args, fmt);
  LOG_VPRINTF(out, fmt, args);
  va_end(args);
 
  LOG_PRINTF(out, " (at %s:%d:%s())\n", file, line, func);
  pthread_mutex_unlock(&log_mutex);
 
function_output:
  return ret;
}
 
#define LOG_ERROR(...)        \
  LOG_output(LOG_LEVEL_ERROR, \
             COLOR_RED,       \
             PREFIX_ERROR,    \
             __FILE__,        \
             __func__,        \
             __LINE__,        \
             __VA_ARGS__)
 
#define LOG_WARNING(...)        \
  LOG_output(LOG_LEVEL_WARNING, \
             COLOR_YELLOW,      \
             PREFIX_WARNING,    \
             __FILE__,          \
             __func__,          \
             __LINE__,          \
             __VA_ARGS__)
 
#define LOG_INFO(...)        \
  LOG_output(LOG_LEVEL_INFO, \
             COLOR_BLUE,     \
             PREFIX_INFO,    \
             __FILE__,       \
             __func__,       \
             __LINE__,       \
             __VA_ARGS__)
 
#define LOG_DEBUG(...)        \
  LOG_output(LOG_LEVEL_DEBUG, \
             COLOR_GREEN,     \
             PREFIX_DEBUG,    \
             __FILE__,        \
             __func__,        \
             __LINE__,        \
             __VA_ARGS__)
 
/* < C++ Compatibility End > */
#ifdef __cplusplus
}
#endif
 
/* < End of header file > */