diff options
Diffstat (limited to 'backend/timing.c')
| -rw-r--r-- | backend/timing.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/backend/timing.c b/backend/timing.c new file mode 100644 index 0000000..1b370ce --- /dev/null +++ b/backend/timing.c @@ -0,0 +1,188 @@ +/* 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 <http://www.gnu.org/licenses/>. + * + * + * 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 <config.h> +#endif + +#include "timing.h" + +#if ENABLE_TIMING + +#include <math.h> +#include <string.h> + +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 */ |