text: /*
   * 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
  