dockapps/wmsupermon/stat_dev.c

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/* Copyright (C) 2006 Sergei Golubchik
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2
as published by the Free Software Foundation
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
/*
originally based on
WMgMon - Window Maker Generic Monitor
by Nicolas Chauvat <nico@caesium.fr>
*/
#include <stdlib.h>
#include <regex.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <math.h>
#include "expr.h"
#include "stat_dev.h"
/******************************************************************************/
/* stat_dev structure and related functions */
/******************************************************************************/
void stat_dev_init(stat_dev * st)
{
bzero(st, sizeof(*st));
st->update_interval=1;
st->hist_update_interval=5;
}
void stat_dev_initstat (stat_dev * st)
{
if (st->flags & F_USED)
update_stat(st); /* to get first value for DIFF */
else
st->next_update=~0; /* that is never */
}
void stat_dev_update_history (stat_dev *st)
{
int i;
for (i=0; i <= P_HIST; i++) {
int j;
history *hist=st->hist[i];
if (!hist) continue;
/* history is updated more often than the value is sampled. Use previous
value to avoid a gap in the history */
if (hist->count == 0)
hist->data[HIST_LAST]=hist->data[HIST_LAST-1];
/* we probably sampled several times since last time we updated,
let's normalize value by dividing by the number of times we sampled */
if (hist->count > 1)
hist->data[HIST_LAST] /= hist->count;
if (i & P_LOG && hist->count)
hist->data[HIST_LAST]=hist->data[HIST_LAST]*3 <= 1 ?
0 : log(hist->data[HIST_LAST]*3);
/* shift values to the left (discard his[0]) */
for (j=1; j < HIST_SIZE; j++)
hist->data[j-1]=hist->data[j];
/* reset sample */
hist->data[HIST_LAST]=0;
hist->count=0;
}
}
/******************************************************************************/
/* update stat functions */
/******************************************************************************/
/* returns 1 on a match */
static int do_regex(stat_dev *st, char *str) {
regmatch_t pmatch[MAX_VAR];
Econtext ctx={str, pmatch, st->diff_old, st->diff_new, st->sum_acc};
if (regexec(&st->regex, str, MAX_VAR, pmatch, 0))
return 0;
st->value[0]=st->expr->eval(st->expr, &ctx)/st->scale;
return 1;
}
static void stat_perror(stat_dev *st, char *op)
{
fprintf(stderr, "[%s]: %s() failed: %s\n", st->name, op, strerror(errno));
}
void update_stat(stat_dev *st)
{
char *buf;
double *tmp;
FILE *f;
int matched=0;
f= (st->source[0] == '!') ?
popen(st->source+1, "r") : fopen(st->source, "r");
if (!f) {
stat_perror(st, "open");
return;
}
if (!st->expr) {
double value;
if (fscanf(f, "%lf", &value) == 1)
st->value[0]=value/st->scale;
goto done;
}
/* ok, doing regexp */
if (st->flags & F_SINGLE_LINE) {
struct stat stat;
if (fstat(fileno(f), &stat) < 0) { stat_perror(st, "fstat"); goto ret; }
if (stat.st_size < MIN_FILE_LEN)
stat.st_size=MIN_FILE_LEN; /* because /proc files may have zero length */
buf=malloc(stat.st_size); /* and it'd better be small! */
if (!buf) { stat_perror(st, "malloc"); goto ret; }
fread(buf, stat.st_size, 1, f);
matched=do_regex(st, buf);
free(buf);
goto done;
}
buf=alloca(TEMP_SIZE);
if (st->nsum) bzero(st->sum_acc, st->nsum*sizeof(double));
while (fgets(buf, TEMP_SIZE, f)) {
if ((matched|=do_regex(st, buf)) && !st->nsum)
break;
}
done:
if (st->flags & F_DEBUG) {
if (matched)
printf("%-4s: %f\n", st->name, st->value[0]);
else
printf("%-4s: match failed\n", st->name);
}
tmp=st->diff_old; st->diff_old=st->diff_new; st->diff_new=tmp;
ret:
(st->source[0] == '!') ? pclose(f) : fclose(f);
}