unix4lyfe git - darkstat/blob - daylog.c

   1 /* darkstat 3
   2  * copyright (c) 2007 Emil Mikulic.
   3  *
   4  * daylog.c: daily usage log
   5  *
   6  * You may use, modify and redistribute this file under the terms of the
   7  * GNU General Public License version 2. (see COPYING.GPL)
   8  */
   9
  10 #define _GNU_SOURCE 1 /* for O_NOFOLLOW on Linux */
  11
  12 #include <sys/types.h>
  13 #include <assert.h>
  14 #include <fcntl.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18
  19 #include "darkstat.h"
  20 #include "err.h"
  21 #include "daylog.h"
  22 #include "str.h"
  23 #include "now.h"
  24
  25 static const char *daylog_fn = NULL;
  26 static time_t today_time, tomorrow_time;
  27 static uint64_t bytes_in, bytes_out, pkts_in, pkts_out;
  28
  29 #define DAYLOG_DATE_LEN 26 /* strlen("1900-01-01 00:00:00 +1234") + 1 */
  30 static char datebuf[DAYLOG_DATE_LEN];
  31
  32 static char *
  33 fmt_date(const time_t when)
  34 {
  35     time_t tmp = when;
  36     if (strftime(datebuf, DAYLOG_DATE_LEN,
  37         "%Y-%m-%d %H:%M:%S %z", localtime(&tmp) ) == 0)
  38             errx(1, "strftime() failed in fmt_date()");
  39     return (datebuf);
  40 }
  41
  42 /* Given some time today, find the first second of tomorrow. */
  43 static time_t
  44 tomorrow(const time_t today)
  45 {
  46    time_t tmp = today;
  47    struct tm tm, *lt;
  48
  49    lt = localtime(&tmp);
  50    memcpy(&tm, lt, sizeof(tm));
  51    tm.tm_sec = 0;
  52    tm.tm_min = 0;
  53    tm.tm_hour = 0;
  54    tm.tm_mday = lt->tm_mday + 1; /* tomorrow */
  55    return mktime(&tm);
  56 }
  57
  58 static int
  59 daylog_open(void)
  60 {
  61    return open(daylog_fn, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW, 0600);
  62 }
  63
  64 static void
  65 daylog_emit(void)
  66 {
  67    int fd = daylog_open();
  68
  69    if (fd != -1) {
  70       struct str *buf = str_make();
  71       char *s;
  72       size_t len;
  73       str_appendf(buf, "%s|%u|%qu|%qu|%qu|%qu\n",
  74          fmt_date(today_time), (unsigned int)today_time,
  75          bytes_in, bytes_out, pkts_in, pkts_out);
  76       str_extract(buf, &len, &s);
  77
  78       (void)write(fd, s, len); /* ignore write errors */
  79       close(fd);
  80       free(s);
  81    }
  82 }
  83
  84 void
  85 daylog_init(const char *filename)
  86 {
  87    int fd;
  88    struct str *buf;
  89    char *s;
  90    size_t len;
  91
  92    daylog_fn = filename;
  93    today_time = time(NULL);
  94    tomorrow_time = tomorrow(today_time);
  95    verbosef("today is %u, tomorrow is %u",
  96       (unsigned int)today_time, (unsigned int)tomorrow_time);
  97    bytes_in = bytes_out = pkts_in = pkts_out = 0;
  98
  99    fd = daylog_open();
 100    if (fd == -1)
 101       err(1, "couldn't open(\"%s\") for append", filename);
 102
 103    buf = str_make();
 104    str_appendf(buf, "# logging started at %s (%u)\n",
 105       fmt_date(today_time), (unsigned int)today_time);
 106    str_extract(buf, &len, &s);
 107    (void)write(fd, s, len); /* ignore write errors */
 108    close(fd);
 109    free(s);
 110 }
 111
 112 void daylog_free(void)
 113 {
 114    int fd;
 115    struct str *buf;
 116    char *s;
 117    size_t len;
 118
 119    today_time = time(NULL);
 120
 121    /* Emit what's currently accumulated. */
 122    daylog_emit();
 123
 124    fd = daylog_open();
 125    if (fd == -1) return;
 126
 127    buf = str_make();
 128    str_appendf(buf, "# logging stopped at %s (%u)\n",
 129       fmt_date(today_time), (unsigned int)today_time);
 130    str_extract(buf, &len, &s);
 131    (void)write(fd, s, len); /* ignore write errors */
 132    close(fd);
 133    free(s);
 134 }
 135
 136 void
 137 daylog_acct(uint64_t amount, enum graph_dir dir)
 138 {
 139    if (daylog_fn == NULL) return; /* disabled */
 140
 141    /* Check if we need to rotate. */
 142    if (now >= tomorrow_time) {
 143       daylog_emit();
 144
 145       today_time = now;
 146       tomorrow_time = tomorrow(today_time);
 147       bytes_in = bytes_out = pkts_in = pkts_out = 0;
 148       verbosef("rotated daylog, tomorrow = %u",
 149          (unsigned int)tomorrow_time);
 150    }
 151
 152    /* Accounting. */
 153    if (dir == GRAPH_IN) {
 154       bytes_in += amount;
 155       pkts_in++;
 156    } else {
 157       assert(dir == GRAPH_OUT);
 158       bytes_out += amount;
 159       pkts_out++;
 160    }
 161 }
 162
 163 /* vim:set ts=3 sw=3 tw=78 et: */