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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* terms governing use, modification, and redistribution, is contained in *
* the COPYING file, which can be found at the root of the source code *
* distribution tree, or in https://www.hdfgroup.org/licenses. *
* If you do not have access to either file, you may request a copy from *
* help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* The example below illustrates the use of the new API with files that are
* opened read-only. Created references to the objects in that file are
* stored into a separate file, and accessed from that file, without the user
* explicitly opening the original file that was referenced.
*/
#include <stdlib.h>
#include "hdf5.h"
#include <assert.h>
#define H5FILE_NAME1 "refer_extern1.h5"
#define H5FILE_NAME2 "refer_extern2.h5"
#define NDIMS 1 /* Number of dimensions */
#define BUF_SIZE 4 /* Size of example buffer */
#define NREFS 1 /* Number of references */
int
main(void)
{
hid_t file1, dset1, space1;
hsize_t dset1_dims[NDIMS] = {BUF_SIZE};
int dset_buf[BUF_SIZE];
hid_t file2, dset2, space2;
hsize_t dset2_dims[NDIMS] = {NREFS};
H5R_ref_t ref_buf[NREFS] = {0};
H5O_type_t obj_type;
int i;
for (i = 0; i < BUF_SIZE; i++)
dset_buf[i] = i;
/* Create file with one dataset and close it */
file1 = H5Fcreate(H5FILE_NAME1, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
space1 = H5Screate_simple(NDIMS, dset1_dims, NULL);
dset1 = H5Dcreate2(file1, "dataset1", H5T_NATIVE_INT, space1, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
H5Dwrite(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, dset_buf);
H5Dclose(dset1);
H5Sclose(space1);
H5Fclose(file1);
/* Create reference to dataset1 in "refer_extern1.h5" */
file1 = H5Fopen(H5FILE_NAME1, H5F_ACC_RDONLY, H5P_DEFAULT);
H5Rcreate_object(file1, "dataset1", H5P_DEFAULT, &ref_buf[0]);
H5Fclose(file1);
/* Store reference in dataset in separate file "refer_extern2.h5" */
file2 = H5Fcreate(H5FILE_NAME2, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
space2 = H5Screate_simple(NDIMS, dset2_dims, NULL);
dset2 = H5Dcreate2(file2, "references", H5T_STD_REF, space2, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
H5Dwrite(dset2, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, ref_buf);
H5Dclose(dset2);
H5Sclose(space2);
H5Fclose(file2);
H5Rdestroy(&ref_buf[0]);
/* Read reference back from "refer_extern2.h5" */
file2 = H5Fopen(H5FILE_NAME2, H5F_ACC_RDONLY, H5P_DEFAULT);
dset2 = H5Dopen2(file2, "references", H5P_DEFAULT);
H5Dread(dset2, H5T_STD_REF, H5S_ALL, H5S_ALL, H5P_DEFAULT, ref_buf);
H5Dclose(dset2);
H5Fclose(file2);
/* Access reference and read dataset data without opening original file */
assert(H5Rget_type((const H5R_ref_t *)&ref_buf[0]) == H5R_OBJECT2);
H5Rget_obj_type3(&ref_buf[0], H5P_DEFAULT, &obj_type);
assert(obj_type == H5O_TYPE_DATASET);
dset1 = H5Ropen_object(&ref_buf[0], H5P_DEFAULT, H5P_DEFAULT);
H5Dread(dset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, dset_buf);
H5Dclose(dset1);
H5Rdestroy(&ref_buf[0]);
for (i = 0; i < BUF_SIZE; i++)
assert(dset_buf[i] == i);
return 0;
}
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