/* timing.c -- optional support for run-time time stamp collection
* Copyright (C) 2009 SEIKO EPSON CORPORATION
*
* License: GPLv2+|iscan
* Authors: AVASYS CORPORATION
*
* This file is part of the SANE backend distributed with Image Scan!
*
* Image Scan!'s SANE backend is free software.
* You can redistribute it and/or modify it under the terms of the GNU
* General Public License as published by the Free Software Foundation;
* either version 2 of the License or at your option any later version.
*
* 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 ought to have received a copy of the GNU General Public License
* along with this package. If not, see .
*
*
* Linking Image Scan!'s SANE backend statically or dynamically with
* other modules is making a combined work based on this SANE backend.
* Thus, the terms and conditions of the GNU General Public License
* cover the whole combination.
*
* As a special exception, the copyright holders of Image Scan!'s SANE
* backend give you permission to link Image Scan!'s SANE backend with
* SANE frontends that communicate with Image Scan!'s SANE backend
* solely through the SANE Application Programming Interface,
* regardless of the license terms of these SANE frontends, and to
* copy and distribute the resulting combined work under terms of your
* choice, provided that every copy of the combined work is
* accompanied by a complete copy of the source code of Image Scan!'s
* SANE backend (the version of Image Scan!'s SANE backend used to
* produce the combined work), being distributed under the terms of
* the GNU General Public License plus this exception. An independent
* module is a module which is not derived from or based on Image
* Scan!'s SANE backend.
*
* As a special exception, the copyright holders of Image Scan!'s SANE
* backend give you permission to link Image Scan!'s SANE backend with
* independent modules that communicate with Image Scan!'s SANE
* backend solely through the "Interpreter" interface, regardless of
* the license terms of these independent modules, and to copy and
* distribute the resulting combined work under terms of your choice,
* provided that every copy of the combined work is accompanied by a
* complete copy of the source code of Image Scan!'s SANE backend (the
* version of Image Scan!'s SANE backend used to produce the combined
* work), being distributed under the terms of the GNU General Public
* License plus this exception. An independent module is a module
* which is not derived from or based on Image Scan!'s SANE backend.
*
* Note that people who make modified versions of Image Scan!'s SANE
* backend are not obligated to grant special exceptions for their
* modified versions; it is their choice whether to do so. The GNU
* General Public License gives permission to release a modified
* version without this exception; this exception also makes it
* possible to release a modified version which carries forward this
* exception.
*/
#ifdef HAVE_CONFIG_H
#include
#endif
#include "timing.h"
#if ENABLE_TIMING
#include
#include
size_t time_pass_count = 0;
struct time_interval_ time_scan;
struct time_interval_ time_pass[TIME_PASS_MAX];
static const long NANOS_PER_SEC = 1000000000;
static void
time_compute_span (struct time_interval_ *m)
{
m->span.t.tv_nsec = m->stop.t.tv_nsec - m->start.t.tv_nsec;
if (0 > m->span.t.tv_nsec)
{
m->span.t.tv_nsec += NANOS_PER_SEC;
m->stop.t.tv_sec -= 1;
}
m->span.t.tv_sec = m->stop.t.tv_sec - m->start.t.tv_sec;
m->span.is_valid = m->start.is_valid && m->stop.is_valid;
}
void
time_clear (void)
{
memset (&time_scan, 0, sizeof (time_scan));
memset ( time_pass, 0, sizeof (*time_pass) * TIME_PASS_MAX);
}
static double
time_stamp_to_double (const struct time_stamp_ *ts)
{
return ((double) ts->t.tv_nsec) / NANOS_PER_SEC + ts->t.tv_sec;
}
static void
time_fprintf_interval (FILE *stream, const struct time_interval_ *ti,
const char *prefix)
{
char str[512];
if (ti->span.is_valid)
snprintf (str, num_of (str), "%s: %f (start: %f, stop: %f)", prefix,
time_stamp_to_double (&ti->span),
time_stamp_to_double (&ti->start),
time_stamp_to_double (&ti->stop));
else if (ti->start.is_valid)
snprintf (str, num_of (str), "%s: --- (start: %f, stop: ---)", prefix,
time_stamp_to_double (&ti->start));
else if (ti->stop.is_valid)
snprintf (str, num_of (str), "%s: --- (start: ---, stop: %f)", prefix,
time_stamp_to_double (&ti->stop));
else
snprintf (str, num_of (str), "%s: --- (start: ---, stop: ---)", prefix);
fprintf (stream, "%s\n", str);
}
/* There is a script in utils/ that can combine the results of
multiple scans (in one or more SANE frontend sessions) into
a single CSV file.
*/
void
time_stats (size_t count)
{
size_t i, n = 0;
double t, sum = 0, sum_sq = 0;
fprintf (stderr, "\f\n"); /* start a new form */
fprintf (stderr, "Per pass timing data (in seconds)\n");
for (i = 0; i < count && i < TIME_PASS_MAX; ++i)
{
time_compute_span (&time_pass[i]);
time_fprintf_interval (stderr, &time_pass[i], "pass");
}
fprintf (stderr, "\n");
fprintf (stderr, "Scan timing data (in seconds)\n");
time_compute_span (&time_scan);
time_fprintf_interval (stderr, &time_scan, "scan");
fprintf (stderr, "\n");
if (time_scan.span.is_valid)
{
if (0 < count)
fprintf (stderr, "Scan avg: %f s/pass\n",
time_stamp_to_double (&time_scan.span) / count);
}
for (i = 0; i < count && i < TIME_PASS_MAX; ++i)
{
if (time_pass[i].span.is_valid)
{
++n;
t = time_stamp_to_double (&time_pass[i].span);
sum += t;
sum_sq += (t * t);
}
}
if (0 != n)
{
fprintf (stderr, "Pass sum: %f s, %zd passes\n", sum, n);
fprintf (stderr, "Pass avg: %f", sum / n);
if (1 < n) /* add standard deviation */
{
fprintf (stderr, " (+/- %f)",
sqrt ((n * sum_sq - sum * sum) / n / (n-1)));
}
fprintf (stderr, " s/pass\n");
}
}
#endif /* ENABLE_TIMING */