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/*
* This program illustrates how references to the objects can be used.
* Program creates two datasets in the file. It also creates the third
* dataset, and references to the first two datasets are stored in it.
* Program reopens the file and reads dataset with the references.
* References are used to open first two datasets and read datatspace
* and datatype information about them.
*
*/
#include<hdf5.h>
#define FILE "refere.h5"
int
main(void) {
hid_t fid; /* File, datasets, datatypes and */
hid_t did_a, sid_a; /* dataspaces identifiers for three */
hid_t did_b, tid_b, sid_b; /* datasets. */
hid_t did_r, tid_r, sid_r;
herr_t status;
hobj_ref_t *wbuf; /* buffer to write to disk */
hobj_ref_t *rbuf; /* buffer to read from disk */
hsize_t dim_r[1];
hsize_t dim_a[1];
hsize_t dim_b[2];
herr_t ret; /* return values */
/*
* Create a file using default properties.
*/
fid = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
/*
* Create dataset "A" in the file.
*/
dim_a[0] = 5;
sid_a = H5Screate_simple(1, dim_a, NULL);
did_a = H5Dcreate(fid, "A", H5T_NATIVE_INT, sid_a, H5P_DEFAULT);
/*
* Create dataset "B" in the file.
*/
dim_b[0] = 2;
dim_b[1] = 6;
sid_b = H5Screate_simple(2, dim_b, NULL);
did_b = H5Dcreate(fid, "B", H5T_NATIVE_FLOAT, sid_b, H5P_DEFAULT);
/*
* Create dataset "R" to store references to the datasets "A" and "B".
*/
dim_r[0] = 2;
sid_r = H5Screate_simple(1, dim_r, NULL);
tid_r = H5Tcopy(H5T_STD_REF_OBJ);
did_r = H5Dcreate(fid, "R", tid_r, sid_r, H5P_DEFAULT );
/*
* Allocate write and read buffers.
*/
wbuf = malloc(sizeof(hobj_ref_t)*2);
rbuf = malloc(sizeof(hobj_ref_t)*2);
/*
* Create references to the datasets "A" and "B"
* and store them in the wbuf.
*/
H5Rcreate(&wbuf[0], fid, "A", H5R_OBJECT, -1);
H5Rcreate(&wbuf[1], fid, "B", H5R_OBJECT, -1);
/*
* Write dataset R using default transfer properties.
*/
status = H5Dwrite(did_r, H5T_STD_REF_OBJ, H5S_ALL, H5S_ALL,
H5P_DEFAULT, wbuf);
/*
* Close all objects.
*/
H5Sclose(sid_a);
H5Dclose(did_a);
H5Sclose(sid_b);
H5Dclose(did_b);
H5Tclose(tid_r);
H5Sclose(sid_r);
H5Dclose(did_r);
H5Fclose(fid);
/*
* Reopen the file.
*/
fid = H5Fopen(FILE, H5F_ACC_RDWR, H5P_DEFAULT);
/*
* Open and read dataset "R".
*/
did_r = H5Dopen(fid, "R");
status = H5Dread(did_r, H5T_STD_REF_OBJ, H5S_ALL, H5S_ALL,
H5P_DEFAULT, rbuf);
/*
* Open dataset A using reference to it.
*/
did_a = H5Rdereference(did_r, H5R_OBJECT, &rbuf[0]);
/*
* Get rank of the dataset "A"
*/
printf("\n");
sid_a = H5Dget_space(did_a);
ret = H5Sget_simple_extent_ndims(sid_a);
if(ret == 1) printf("Rank of A is %d.\n", ret);
printf("\n");
/*
* Get datatype of the dataset "B"
*/
did_b = H5Rdereference(did_r, H5R_OBJECT, &rbuf[1]);
tid_b = H5Dget_type(did_b);
if(H5Tequal(tid_b, H5T_NATIVE_FLOAT))
printf("Datatype of B is H5T_NATIVE_FLOAT.\n");
printf("\n");
/*
* Close all objects.
*/
H5Dclose(did_a);
H5Sclose(sid_a);
H5Dclose(did_b);
H5Tclose(tid_b);
H5Fclose(fid);
return 0;
}
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