boinc/client/time_stats.C

114 lines
3.3 KiB
C

// The contents of this file are subject to the Mozilla Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
// License for the specific language governing rights and limitations
// under the License.
//
// The Original Code is the Berkeley Open Infrastructure for Network Computing.
//
// The Initial Developer of the Original Code is the SETI@home project.
// Portions created by the SETI@home project are Copyright (C) 2002
// University of California at Berkeley. All Rights Reserved.
//
// Contributor(s):
//
#include <stdio.h>
#include <time.h>
#include <math.h>
#include "parse.h"
#include "error_numbers.h"
#include "time_stats.h"
// exponential decay constant.
// The last 30 days have a weight of 1/e;
// everything before that has a weight of (1-1/e)
#define ALPHA (3600.*24*7*30)
TIME_STATS::TIME_STATS() {
first = true;
last_update = 0;
on_frac = 1;
connected_frac = 1;
active_frac = 1;
}
void TIME_STATS::update(bool is_connected, bool is_active) {
int now = time(0), dt;
double w1, w2;
if (last_update == 0) {
// this is the first time this client has executed.
// Assume that its state has always been what it is now
on_frac = 1;
connected_frac = is_connected?1:0;
active_frac = is_active?1:0;
first = false;
last_update = now;
} else {
dt = now - last_update;
if (dt <= 0) return;
w1 = 1 - exp(-dt/ALPHA);
w2 = 1 - w1;
if (first) {
// the client has just started; this is the first call.
// The client has been off (and disconnected and inactive)
// since the last time it ran.
on_frac *= w2;
connected_frac *= w2;
active_frac *= w2;
first = false;
} else {
on_frac = w1 + w2*on_frac;
connected_frac *= w2;
if (is_connected) connected_frac += w1;
active_frac *= w2;
if (is_active) active_frac += w1;
}
last_update = now;
}
}
int TIME_STATS::write(FILE* out, bool to_server) {
fprintf(out,
"<time_stats>\n"
" <on_frac>%f</on_frac>\n"
" <connected_frac>%f</connected_frac>\n"
" <active_frac>%f</active_frac>\n",
on_frac,
connected_frac,
active_frac
);
if (!to_server) {
fprintf(out,
" <last_update>%d</last_update>\n",
last_update
);
}
fprintf(out, "</time_stats>\n");
return 0;
}
int TIME_STATS::parse(FILE* in) {
char buf[256];
while (fgets(buf, 256, in)) {
if (match_tag(buf, "</time_stats>")) return 0;
else if (parse_int(buf, "<last_update>", last_update)) continue;
else if (parse_double(buf, "<on_frac>", on_frac)) continue;
else if (parse_double(buf, "<connected_frac>", connected_frac)) continue;
else if (parse_double(buf, "<active_frac>", active_frac)) continue;
else fprintf(stderr, "TIME_STATS:: parse(): unrecognized: %s\n", buf);
}
return ERR_XML_PARSE;
}