/* This is part of the netCDF package. Copyright 2011 University Corporation for Atmospheric Research/Unidata See COPYRIGHT file for conditions of use. Test netcdf-4 chunking. */ #include #define FILE_NAME "tst_chunks2.nc" /* Calculate the waste of the chunking. A waste of 10% means the * chunked data is 10% larget then the unchunked data. */ static int calculate_waste(int ndims, size_t *dimlen, size_t *chunksize, float *waste) { int d; float chunked = 1, unchunked = 1; size_t *num_chunks; size_t chunk_size = 1; assert(waste && dimlen && chunksize && ndims); if (!(num_chunks = calloc(ndims, sizeof(size_t)))) ERR; printf("\n"); /* Caclulate the total space taken up by the chunked data. */ for (d = 0; d < ndims; d++) { /* How many chunks along this dimension are required to hold all the data? */ for (num_chunks[d] = 0; (num_chunks[d] * chunksize[d]) < (dimlen[d] ? dimlen[d] : 1); num_chunks[d]++) ; chunked *= (num_chunks[d] * chunksize[d]); } /* Calculate the minimum space required for this data * (i.e. unchunked) or one record of it. */ for (d = 0; d < ndims; d++) unchunked *= (dimlen[d] ? dimlen[d] : 1); printf("size for unchunked %g elements; size for chunked %g elements\n", unchunked, chunked); /* Percent of the chunked file that is wasted space. */ *waste = ((float)(chunked - unchunked) / (float)chunked) * 100.0; printf("\ndimlen\tchunksize\tnum_chunks\n"); for (d = 0; d < ndims; d++) { printf("%ld\t%ld\t\t%ld\n", dimlen[d], chunksize[d], num_chunks[d]); chunk_size *= chunksize[d]; } printf("size of chunk: %ld elements; wasted space: %2.2f percent\n", chunk_size, *waste); free(num_chunks); return 0; } int main(int argc, char **argv) { printf("\n*** Testing netcdf-4 variable chunking.\n"); printf("**** testing default chunksizes..."); { #define NDIMS3 3 #define NUM_VARS 1 #define Y_NAME "y" #define X_NAME "x" #define Z_NAME "z" #define VAR_NAME_JOE "joe" #define XDIM_LEN 2 #define YDIM_LEN 5 #define ZDIM_LEN 3000 #define MAX_WASTE 10.0 int varid, ncid, dims[NDIMS3], dims_in[NDIMS3]; int ndims, nvars, ngatts, unlimdimid, natts; char name_in[NC_MAX_NAME + 1]; nc_type type_in; size_t len_in[NDIMS3]; int storage = 0; size_t chunksizes[NDIMS3]; float waste = 0; /* Create a file with 3D var, turn on chunking, but don't provide chunksizes. */ if (nc_create(FILE_NAME, NC_NETCDF4 | NC_CLOBBER, &ncid)) ERR; if (nc_def_dim(ncid, X_NAME, XDIM_LEN, &dims[0])) ERR; if (nc_def_dim(ncid, Y_NAME, YDIM_LEN, &dims[1])) ERR; if (nc_def_dim(ncid, Z_NAME, ZDIM_LEN, &dims[2])) ERR; if (nc_def_var(ncid, VAR_NAME_JOE, NC_FLOAT, NDIMS3, dims, &varid)) ERR; if (nc_def_var_chunking(ncid, 0, NC_CHUNKED, NULL)) ERR; /* Check it out. */ if (nc_inq(ncid, &ndims, &nvars, &ngatts, &unlimdimid)) ERR; if (nvars != NUM_VARS || ndims != NDIMS3 || ngatts != 0 || unlimdimid != -1) ERR; if (nc_inq_var(ncid, 0, name_in, &type_in, &ndims, dims_in, &natts)) ERR; if (strcmp(name_in, VAR_NAME_JOE) || type_in != NC_FLOAT || ndims != NDIMS3 || dims_in[0] != dims[0] || dims_in[1] != dims[1] || dims_in[2] != dims[2] || natts != 0) ERR; if (nc_inq_dim(ncid, 0, name_in, &len_in[0])) ERR; if (strcmp(name_in, X_NAME) || len_in[0] != XDIM_LEN) ERR; if (nc_inq_dim(ncid, 1, name_in, &len_in[1])) ERR; if (strcmp(name_in, Y_NAME) || len_in[1] != YDIM_LEN) ERR; if (nc_inq_dim(ncid, 2, name_in, &len_in[2])) ERR; if (strcmp(name_in, Z_NAME) || len_in[2] != ZDIM_LEN) ERR; if (nc_inq_var_chunking(ncid, 0, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (nc_close(ncid)) ERR; /* Open the file and check again. */ if (nc_open(FILE_NAME, NC_WRITE, &ncid)) ERR; if (nc_inq(ncid, &ndims, &nvars, &ngatts, &unlimdimid)) ERR; if (nvars != NUM_VARS || ndims != NDIMS3 || ngatts != 0 || unlimdimid != -1) ERR; if (nc_inq_var(ncid, 0, name_in, &type_in, &ndims, dims_in, &natts)) ERR; if (strcmp(name_in, VAR_NAME_JOE) || type_in != NC_FLOAT || ndims != NDIMS3 || dims_in[0] != dims[0] || dims_in[1] != dims[1] || dims_in[2] != dims[2] || natts != 0) ERR; if (nc_inq_dim(ncid, 0, name_in, &len_in[0])) ERR; if (strcmp(name_in, X_NAME) || len_in[0] != XDIM_LEN) ERR; if (nc_inq_dim(ncid, 1, name_in, &len_in[1])) ERR; if (strcmp(name_in, Y_NAME) || len_in[1] != YDIM_LEN) ERR; if (nc_inq_dim(ncid, 2, name_in, &len_in[2])) ERR; if (strcmp(name_in, Z_NAME) || len_in[2] != ZDIM_LEN) ERR; if (nc_inq_var_chunking(ncid, 0, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (calculate_waste(NDIMS3, len_in, chunksizes, &waste)) ERR; /*if (waste > MAX_WASTE) ERR;*/ if (nc_close(ncid)) ERR; } SUMMARIZE_ERR; printf("**** testing default chunksizes some more for a 3D var..."); { #define NDIMS3 3 #define VAR_NAME "op-amp" int varid, ncid; int dimids[NDIMS3]; size_t dim_len[NDIMS3] = {1, 11, 152750}; int storage = 0; size_t chunksizes[NDIMS3]; int d; char dim_name[NC_MAX_NAME + 1]; float waste; if (nc_create(FILE_NAME, NC_NETCDF4 | NC_CLOBBER, &ncid)) ERR; /* Create a few dimensions. */ for (d = 0; d < NDIMS3; d++) { sprintf(dim_name, "dim_%d", d); if (nc_def_dim(ncid, dim_name, dim_len[d], &dimids[d])) ERR; } /* Define a var with these dimensions, and turn on chunking. */ if (nc_def_var(ncid, VAR_NAME, NC_FLOAT, NDIMS3, dimids, &varid)) ERR; if (nc_def_var_chunking(ncid, varid, NC_CHUNKED, NULL)) ERR; /* Check how default chunking worked. */ if (nc_inq_var_chunking(ncid, varid, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (calculate_waste(NDIMS3, dim_len, chunksizes, &waste)) ERR; /* if (waste > MAX_WASTE) ERR;*/ if (nc_close(ncid)) ERR; /* Open the file and check. */ if (nc_open(FILE_NAME, NC_WRITE, &ncid)) ERR; if (nc_close(ncid)) ERR; } SUMMARIZE_ERR; printf("**** testing default chunksizes for very large 3D var..."); { #define NDIMS3 3 int varid, ncid; int dimids[NDIMS3]; size_t dim_len[NDIMS3] = {1804289383, 846930886, 1681692777}; int storage = 0; size_t chunksizes[NDIMS3]; int d; char dim_name[NC_MAX_NAME + 1]; float waste; if (nc_create(FILE_NAME, NC_NETCDF4 | NC_CLOBBER, &ncid)) ERR; /* Create a few dimensions. */ for (d = 0; d < NDIMS3; d++) { sprintf(dim_name, "dim_%d", d); if (nc_def_dim(ncid, dim_name, dim_len[d], &dimids[d])) ERR; } /* Define a var with these dimensions, and turn on chunking. */ if (nc_def_var(ncid, VAR_NAME, NC_FLOAT, NDIMS3, dimids, &varid)) ERR; if (nc_def_var_chunking(ncid, varid, NC_CHUNKED, NULL)) ERR; /* Check how default chunking worked. */ if (nc_inq_var_chunking(ncid, varid, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (calculate_waste(NDIMS3, dim_len, chunksizes, &waste)) ERR; /* if (waste > MAX_WASTE) ERR;*/ if (nc_close(ncid)) ERR; /* Open the file and check. */ if (nc_open(FILE_NAME, NC_WRITE, &ncid)) ERR; if (nc_close(ncid)) ERR; } SUMMARIZE_ERR; printf("**** testing default chunksizes some randomly sized 3D vars..."); { #define NDIMS3 3 #define NUM_TESTS 5 int varid, ncid; int dimids[NDIMS3]; size_t dim_len[NDIMS3]; int storage = 0; size_t chunksizes[NDIMS3]; int d, t; char dim_name[NC_MAX_NAME + 1]; float waste; for (t = 0; t < NUM_TESTS; t++) { if (nc_create(FILE_NAME, NC_NETCDF4 | NC_CLOBBER, &ncid)) ERR; /* Create a few dimensions. */ for (d = 0; d < NDIMS3; d++) { dim_len[d] = rand(); sprintf(dim_name, "dim_%d", d); if (nc_def_dim(ncid, dim_name, dim_len[d], &dimids[d])) ERR; } /* Define a var with these dimensions, and turn on chunking. */ if (nc_def_var(ncid, VAR_NAME, NC_FLOAT, NDIMS3, dimids, &varid)) ERR; if (nc_def_var_chunking(ncid, varid, NC_CHUNKED, NULL)) ERR; /* Check how well default chunking worked. */ if (nc_inq_var_chunking(ncid, varid, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (calculate_waste(NDIMS3, dim_len, chunksizes, &waste)) ERR; if (waste > MAX_WASTE) ERR; if (nc_close(ncid)) ERR; } } SUMMARIZE_ERR; printf("**** testing default chunksizes some randomly sized 3D vars, with one small dimension..."); { #define NDIMS3 3 #define NUM_TESTS1 1 int varid, ncid; int dimids[NDIMS3]; size_t dim_len[NDIMS3]; int storage = 0; size_t chunksizes[NDIMS3]; int d, t; char dim_name[NC_MAX_NAME + 1]; float waste; for (t = 0; t < NUM_TESTS1; t++) { if (nc_create(FILE_NAME, NC_NETCDF4 | NC_CLOBBER, &ncid)) ERR; dim_len[0] = rand(); dim_len[1] = rand(); dim_len[2] = rand() % 1000; /* Create a few dimensions. */ for (d = 0; d < NDIMS3; d++) { sprintf(dim_name, "dim_%d", d); if (nc_def_dim(ncid, dim_name, dim_len[d], &dimids[d])) ERR; } /* Define a var with these dimensions, and turn on chunking. */ if (nc_def_var(ncid, VAR_NAME, NC_FLOAT, NDIMS3, dimids, &varid)) ERR; if (nc_def_var_chunking(ncid, varid, NC_CHUNKED, NULL)) ERR; /* Check how well default chunking worked. */ if (nc_inq_var_chunking(ncid, varid, &storage, chunksizes)) ERR; if (storage != NC_CHUNKED) ERR; if (calculate_waste(NDIMS3, dim_len, chunksizes, &waste)) ERR; if (waste > MAX_WASTE) ERR; if (nc_close(ncid)) ERR; } } SUMMARIZE_ERR; FINAL_RESULTS; }