netcdf-c/nc_test4/bm_many_atts.c

104 lines
3.0 KiB
C

/*
Copyright 2010, UCAR/Unidata
See COPYRIGHT file for copying and redistribution conditions.
This program benchmarks creating a netCDF file with many objects.
$Id $
*/
#include <config.h>
#include <nc_tests.h>
#include <netcdf.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h> /* Extra high precision time info. */
/* We will create this file. */
#define FILE_NAME "bm_many_atts.nc"
/* Subtract the `struct timeval' values X and Y, storing the result in
RESULT. Return 1 if the difference is negative, otherwise 0. This
function from the GNU documentation. */
int
timeval_subtract (result, x, y)
struct timeval *result, *x, *y;
{
/* Perform the carry for the later subtraction by updating Y. */
if (x->tv_usec < y->tv_usec) {
int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
y->tv_usec -= 1000000 * nsec;
y->tv_sec += nsec;
}
if (x->tv_usec - y->tv_usec > 1000000) {
int nsec = (x->tv_usec - y->tv_usec) / 1000000;
y->tv_usec += 1000000 * nsec;
y->tv_sec -= nsec;
}
/* Compute the time remaining to wait.
`tv_usec' is certainly positive. */
result->tv_sec = x->tv_sec - y->tv_sec;
result->tv_usec = x->tv_usec - y->tv_usec;
/* Return 1 if result is negative. */
return x->tv_sec < y->tv_sec;
}
int main(int argc, char **argv)
{
struct timeval start_time, end_time, diff_time;
double sec;
int nitem = 1000; /* default number of objects of each type */
int i;
int ncid;
int data[] = {42};
int g, grp, numgrp;
char gname[16];
int a, numatt, an, aleft, natts;
if(argc > 2) { /* Usage */
printf("NetCDF performance test, writing many groups, variables, and attributes.\n");
printf("Usage:\t%s [N]\n", argv[0]);
printf("\tN: number of objects\n");
return(0);
}
for(i = 1; i < argc; i++) {
nitem = atoi(argv[i]);
}
/* create new file */
if (nc_create(FILE_NAME, NC_NETCDF4, &ncid)) ERR;
/* create N group/global attributes, printing time after every 100.
* Because only NC_MAX_ATTRS are permitted per group, create the
* necessary number of groups to hold nitem attributes. */
numatt = nitem;
a = 1;
numgrp = (numatt - 1) / NC_MAX_ATTRS + 1;
aleft = numatt - (NC_MAX_ATTRS * (numgrp - 1));
if (gettimeofday(&start_time, NULL))
ERR;
for(g = 1; g < numgrp + 1; g++) {
sprintf(gname, "group%d", g);
if (nc_def_grp(ncid, gname, &grp)) ERR;
natts = g < numgrp ? NC_MAX_ATTRS : aleft; /* leftovers on last time through */
for(an = 1; an < natts + 1; an++) {
char aname[20];
sprintf(aname, "attribute%d", a);
if (nc_put_att_int(grp, NC_GLOBAL, aname, NC_INT, 1, data)) ERR;
if(a%100 == 0) { /* only print every 100th attribute name */
if (gettimeofday(&end_time, NULL)) ERR;
if (timeval_subtract(&diff_time, &end_time, &start_time)) ERR;
sec = diff_time.tv_sec + 1.0e-6 * diff_time.tv_usec;
printf("%s/%s\t%.3g sec\n", gname, aname, sec);
}
a++;
}
}
nc_close(ncid);
return(0);
}