src/videolib/videolib_dbglog.c

   1 /* coded by Ketmar // Vampire Avalon (psyc://ketmar.no-ip.org/~Ketmar)
   2  * Understanding is not required. Only obedience.
   3  *
   4  * This program is free software. It comes without any warranty, to
   5  * the extent permitted by applicable law. You can redistribute it
   6  * and/or modify it under the terms of the Do What The Fuck You Want
   7  * To Public License, Version 2, as published by Sam Hocevar. See
   8  * http://sam.zoy.org/wtfpl/COPYING for more details.
   9  */
  10 /* debug logs */
  11 #include "videolib.h"
  12
  13 #include <fcntl.h>
  14 #include <stdarg.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <time.h>
  19 #include <unistd.h>
  20
  21 #include <sys/stat.h>
  22 #include <sys/types.h>
  23
  24
  25 ////////////////////////////////////////////////////////////////////////////////
  26 static char dbg_locker = 0;
  27
  28 void vl_dbglog_lock (void) {
  29   while (__sync_bool_compare_and_swap(&dbg_locker, 0, 1)) usleep(1);
  30 }
  31
  32
  33 void vl_dbglog_unlock (void) {
  34   /*
  35   __sync_synchronize();
  36   dbg_locker = 0;
  37   */
  38   __sync_fetch_and_and(&dbg_locker, 0);
  39 }
  40
  41
  42 ////////////////////////////////////////////////////////////////////////////////
  43 #ifdef VIDEOLIB_ENABLE_DEBUG_LOG
  44 static pid_t mypid;
  45 static char log_file_name[8192];
  46 static char bin_path[8192];
  47 static int flag_dofile = 1; /* default: yes */
  48 static int flag_dostderr = 1; /* default: yes */
  49 static int logfile = -1;
  50 static int logfile_err = 0;
  51
  52
  53 static __attribute__((destructor)) void _dtor_dbglog (void) {
  54   vl_dbglog_lock();
  55   if (logfile >= 0) {
  56     close(logfile);
  57     logfile = -1;
  58   }
  59   vl_dbglog_unlock();
  60 }
  61
  62
  63 static __attribute__((constructor)) void _ctor_dbglog (void) {
  64   mypid = getpid();
  65   bin_path[sizeof(bin_path)-1] = 0;
  66   if (readlink("/proc/self/exe", bin_path, sizeof(bin_path)-1) < 0) {
  67     strcpy(bin_path, "./");
  68   } else {
  69     char *p = strrchr(bin_path, '/');
  70     if (p == NULL) strcpy(bin_path, "./"); else p[1] = '\0';
  71   }
  72   if (bin_path[strlen(bin_path)-1] != '/') strcat(bin_path, "/"); // just in case, hehe
  73   log_file_name[0] = 0;
  74   vl_dbglog_set_filename("debug.log");
  75 }
  76
  77
  78 void vl_dbglog_set_filename (const char *fname) {
  79   vl_dbglog_lock();
  80   if (fname != NULL && fname[0] && strlen(fname)) {
  81     if (fname[0] != '/' && !(fname[0] == '.' && fname[1] == '/') && !(fname[0] == '.' && fname[1] == '.' && fname[2] == '/')) {
  82       snprintf(log_file_name, sizeof(log_file_name), "%s%s", bin_path, fname);
  83     } else {
  84       snprintf(log_file_name, sizeof(log_file_name), "%s", fname);
  85     }
  86   } else {
  87     log_file_name[0] = '\0';
  88   }
  89   if (logfile >= 0) {
  90     close(logfile);
  91     logfile = -1;
  92   }
  93   logfile_err = (log_file_name[0] == 0);
  94   vl_dbglog_unlock();
  95 }
  96
  97
  98 int vl_dbglog_set_fileout (int doIt) {
  99   int old;
 100   vl_dbglog_lock();
 101   old = flag_dofile;
 102   flag_dofile = !!doIt;
 103   vl_dbglog_unlock();
 104   return old;
 105 }
 106
 107
 108 int vl_dbglog_set_stderr (int doIt) {
 109   int old;
 110   vl_dbglog_lock();
 111   old = flag_dostderr;
 112   flag_dostderr = !!doIt;
 113   vl_dbglog_unlock();
 114   return old;
 115 }
 116
 117
 118 void vl_dlogf (const char *fmt, ...) {
 119   va_list ap;
 120   va_start(ap, fmt);
 121   dlogfVA(fmt, ap);
 122   va_end(ap);
 123 }
 124
 125
 126 static void write_to_file (int fd, const char *pfx, const char *buf) {
 127   int pfxlen = strlen(pfx);
 128   while (*buf) {
 129     const char *eol;
 130     // first write prefix
 131     if (pfxlen > 0) write(fd, pfx, pfxlen);
 132     // now look for EOL
 133     if ((eol = strpbrk(buf, "\r\n")) == NULL) eol = buf+strlen(buf);
 134     // write string part
 135     if (eol > buf) write(fd, buf, eol-buf);
 136     // write EOL
 137     write(fd, "\n", 1);
 138     // skip EOL
 139     switch ((buf = eol)[0]) {
 140       case '\0': break; // done with buf
 141       case '\r':
 142         if (*(++buf) != '\n') break;
 143         // fallthru
 144       default: ++buf; break;
 145     }
 146   }
 147 }
 148
 149
 150 void dlogfVA (const char *fmt, va_list inap) {
 151   char timebuf[128];
 152   char buf[512], *dbuf = buf;
 153   time_t t;
 154   int buf_sz;
 155   struct tm bt;
 156   va_list ap;
 157
 158   if (fmt == NULL) return;
 159   vl_dbglog_lock();
 160   if (!flag_dofile && !flag_dostderr) goto quit;
 161
 162   t = time(NULL);
 163   localtime_r(&t, &bt);
 164   sprintf(timebuf, "[%05i] %04i/%02i/%02i %02i:%02i:%02i: ",
 165     mypid,
 166     bt.tm_year+1900, bt.tm_mon+1, bt.tm_mday,
 167     bt.tm_hour, bt.tm_min, bt.tm_sec
 168   );
 169
 170   memset(buf, 0, sizeof(buf));
 171   va_copy(ap, inap);
 172   if ((buf_sz = vsnprintf(buf, sizeof(buf), fmt, ap)) >= sizeof(buf)) {
 173     va_end(ap);
 174     if ((dbuf = malloc(buf_sz+1)) == NULL) goto quit; // alas, out of memory
 175     va_copy(ap, inap);
 176     vsnprintf(dbuf, buf_sz+1, fmt, ap);
 177   }
 178   va_end(ap);
 179
 180   if (flag_dofile && logfile < 0 && logfile_err == 0 && log_file_name[0]) {
 181     // try to open debug log file
 182     logfile = open(log_file_name, O_WRONLY|O_APPEND|O_CLOEXEC|O_CREAT, 0644);
 183     ++logfile_err; // don't do this again
 184   }
 185
 186   if (flag_dofile && logfile >= 0) {
 187     write_to_file(logfile, timebuf, dbuf);
 188   }
 189
 190   if (flag_dostderr) {
 191     write(2, "\r\x1b[K", 4);
 192     write_to_file(2, timebuf+13, dbuf); // skip PID and year
 193   }
 194
 195   if (dbuf != buf) free(dbuf);
 196
 197 quit:
 198   vl_dbglog_unlock();
 199 }
 200
 201 #else
 202
 203 void vl_dbglog_set_filename (const char *fname) {}
 204 int vl_dbglog_set_stderr (int doIt) { return 0; }
 205 int vl_dbglog_set_fileout (int doIt) { return 0; }
 206
 207 #endif