/* Copyright 2010, UCAR/Unidata See COPYRIGHT file for copying and redistribution conditions. This program benchmarks creating a netCDF file with many objects. $Id $ */ #include #include #include #include #include #include #include /* Extra high precision time info. */ /* We will create this file. */ #define FILE_NAME "bm_many_atts.nc" 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 (nc4_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); }