/*  timing.h -- 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.
 */


#ifndef timing_h_included
#define timing_h_included

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>

#ifndef ENABLE_TIMING
#define ENABLE_TIMING 0
#endif

#define TIME_PASS_MAX 100
extern size_t time_pass_count;

#if !ENABLE_TIMING              /* turn API calls into no-ops */

#define time_clear()             do {} while (0)
#define time_stamp(interval,end) do {} while (0)
#define time_stats(count)        do {} while (0)

#else                           /* do something useful */

#include <time.h>
#include "defines.h"

struct time_stamp_
{
  bool is_valid;
  struct timespec t;
};

struct time_interval_
{
  struct time_stamp_ start;
  struct time_stamp_ stop;
  struct time_stamp_ span;
};

extern struct time_interval_ time_scan;
extern struct time_interval_ time_pass[TIME_PASS_MAX];

#define time_stamp(interval,end)                                      \
  do {                                                                \
    interval.end.is_valid = (0 == clock_gettime (CLOCK_MONOTONIC,     \
                                                 &(interval.end.t))); \
  } while (0)

void time_clear (void);
void time_stats (size_t count);

#endif  /* ENABLE_TIMING */

#endif  /* !defined (timing_h_included) */