git.sesse.net Git - cubemap/blob - log.cpp

   1 #include "log.h"
   2
   3 #include <stdio.h>
   4 #include <stdarg.h>
   5 #include <syslog.h>
   6 #include <assert.h>
   7 #include <string>
   8 #include <vector>
   9
  10 using namespace std;
  11
  12 // Yes, it's a bit ugly.
  13 #define SYSLOG_FAKE_FILE (static_cast<FILE *>(NULL))
  14
  15 bool logging_started = false;
  16 std::vector<FILE *> log_destinations;
  17
  18 void add_log_destination_file(const std::string &filename)
  19 {
  20         FILE *fp = fopen(filename.c_str(), "a");
  21         if (fp == NULL) {
  22                 perror(filename.c_str());
  23                 return;
  24         }
  25
  26         log_destinations.push_back(fp);
  27 }
  28
  29 void add_log_destination_console()
  30 {
  31         log_destinations.push_back(stderr);
  32 }
  33
  34 void add_log_destination_syslog()
  35 {
  36         openlog("cubemap", LOG_PID, LOG_DAEMON);
  37         log_destinations.push_back(SYSLOG_FAKE_FILE);
  38 }
  39
  40 void start_logging()
  41 {
  42         logging_started = true;
  43 }
  44
  45 void shut_down_logging()
  46 {
  47         for (size_t i = 0; i < log_destinations.size(); ++i) {
  48                 if (log_destinations[i] == SYSLOG_FAKE_FILE) {
  49                         closelog();
  50                 } else if (log_destinations[i] != stderr) {
  51                         if (fclose(log_destinations[i]) != 0) {
  52                                 perror("fclose");
  53                         }
  54                 }
  55         }
  56         log_destinations.clear();
  57         logging_started = false;
  58 }
  59
  60 void log(LogLevel log_level, const char *fmt, ...)
  61 {
  62         char formatted_msg[4096];
  63         va_list ap;
  64         va_start(ap, fmt);
  65         vsnprintf(formatted_msg, sizeof(formatted_msg), fmt, ap);
  66         va_end(ap);
  67
  68         const char *log_level_str;
  69         int syslog_level;
  70
  71         switch (log_level) {
  72         case NO_LEVEL:
  73                 log_level_str = "";
  74                 syslog_level = LOG_INFO;
  75                 break;
  76         case INFO:
  77                 log_level_str = "INFO: ";
  78                 syslog_level = LOG_INFO;
  79                 break;
  80         case WARNING:
  81                 log_level_str = "WARNING: ";
  82                 syslog_level = LOG_WARNING;
  83                 break;
  84         case ERROR:
  85                 log_level_str = "ERROR: ";
  86                 syslog_level = LOG_ERR;
  87                 break;
  88         default:
  89                 assert(false);
  90         }
  91
  92         // Log to stderr if logging hasn't been set up yet. Note that this means
  93         // that such messages will come even if there are no “error_log” lines.
  94         if (!logging_started) {
  95                 fprintf(stderr, "%s%s\n", log_level_str, formatted_msg);
  96                 return;
  97         }
  98
  99         for (size_t i = 0; i < log_destinations.size(); ++i) {
 100                 if (log_destinations[i] == SYSLOG_FAKE_FILE) {
 101                         syslog(syslog_level, "%s", formatted_msg);
 102                 } else {
 103                         int err = fprintf(log_destinations[i], "%s%s\n", log_level_str, formatted_msg);
 104                         if (err < 0) {
 105                                 perror("fprintf");
 106                         }
 107                         if (log_destinations[i] != stderr) {
 108                                 fflush(log_destinations[i]);
 109                         }
 110                 }
 111         }
 112 }