util.h

/*
 * Copyright (c) 2010 Andreas Kloeckner
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef UTIL_H
#define UTIL_H

#include <stdlib.h>
#include <stdio.h>

#ifdef __APPLE__

#include <sys/time.h>

typedef struct timeval timestamp_type;

static void get_timestamp(timestamp_type *t)
{
  gettimeofday(t, NULL);
}

static double timestamp_diff_in_seconds(timestamp_type start,
timestamp_type end)
{
  /* Perform the carry for the later subtraction by updating start. */
  if (end.tv_usec < start.tv_usec) {
    int nsec = (start.tv_usec - end.tv_usec) / 1000000 + 1;
    start.tv_usec -= 1000000 * nsec;
    start.tv_sec += nsec;
  }
  if (end.tv_usec - start.tv_usec > 1000000) {
    int nsec = (end.tv_usec - start.tv_usec) / 1000000;
    start.tv_usec += 1000000 * nsec;
    start.tv_sec -= nsec;
  }

  return end.tv_sec - start.tv_sec + (end.tv_usec - start.tv_usec)*1e-6;
}

#else

#include <time.h>

typedef struct timespec timestamp_type;

static void get_timestamp(timestamp_type *t)
{
  clock_gettime(CLOCK_REALTIME, t);
}

static double timestamp_diff_in_seconds(timestamp_type start, timestamp_type end)
{
  struct timespec temp;
  if ((end.tv_nsec-start.tv_nsec)<0) {
    temp.tv_sec = end.tv_sec-start.tv_sec-1;
    temp.tv_nsec = 1000000000+end.tv_nsec-start.tv_nsec;
  } else {
    temp.tv_sec = end.tv_sec-start.tv_sec;
    temp.tv_nsec = end.tv_nsec-start.tv_nsec;
  }
  return temp.tv_sec + 1e-9*temp.tv_nsec;
}



#endif

#define MAX_LINE_LEN 1024

/*
 * Read a line from stdin.
 * From http://stackoverflow.com/a/314422/1148634
 */
static char *read_a_line(void)
{
  char * line = (char *) malloc(MAX_LINE_LEN), * linep = line;
  size_t lenmax = MAX_LINE_LEN, len = lenmax;
  int c;

  if(line == NULL)
    return NULL;

  for(;;)
  {
    c = fgetc(stdin);
    if(c == EOF)
      break;

    if(--len == 0)
    {
      char *linen = (char *) realloc(linep, lenmax *= 2);
      len = lenmax;

      if(linen == NULL)
      {
        free(linep);
        return NULL;
      }
      line = linen + (line - linep);
      linep = linen;
    }

    if((*line++ = c) == '\n')
      break;
  }
  *line = '\0';
  return linep;
}

#endif