static void plist_link_example(void)
{
hid_t file_id;
hid_t group_id, group2_id;
hid_t gapl_id;
char *path = NULL;
/* Define the link class that we'll use to register "plist
* links" using the callback we defined above.
* A link class can have NULL for any callback except its traverse
* callback.
*/
const H5L_class_t UD_plist_class[1] = {{
H5L_LINK_CLASS_T_VERS, /* Version number for this struct.
* This field is always H5L_LINK_CLASS_T_VERS */
(H5L_type_t)UD_PLIST_CLASS, /* Link class id number. This can be any
* value between H5L_TYPE_UD_MIN (64) and
* H5L_TYPE_MAX (255). It should be a
* value that isn't already being used by
* another kind of link. We'll use 67. */
"UD_plist_link", /* Link class name for debugging */
NULL, /* Creation callback */
NULL, /* Move callback */
NULL, /* Copy callback */
UD_plist_traverse, /* The actual traversal function */
NULL, /* Deletion callback */
NULL /* Query callback */
}};
/* First, create a file and two objects within the file for the link to
* point to.
*/
file_id = H5Fcreate(HARD_LINK_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
group_id = H5Gcreate2(file_id, "group_1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
H5Gclose(group_id);
group_id = H5Gcreate2(file_id, "group_1/group_2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
H5Gclose(group_id);
/* Register "plist links" and create one. It has no udata at all. */
H5Lregister(UD_plist_class);
H5Lcreate_ud(file_id, "plist_link", (H5L_type_t)UD_PLIST_CLASS, NULL, 0,
H5P_DEFAULT, H5P_DEFAULT);
/* Create a group access property list to pass in the target for the
* plist link.
*/
gapl_id = H5Pcreate(H5P_GROUP_ACCESS);
/* There is no HDF5 API for setting the property that controls these
* links, so we have to add the property manually
*/
H5Pinsert2(gapl_id, PLIST_LINK_PROP, sizeof(const char *), &(path), NULL, NULL, NULL, NULL, NULL, NULL);
/* Set the property to point to the first group. */
path = "group_1";
H5Pset(gapl_id, PLIST_LINK_PROP, &path);
/* Open the first group through the plist link using the GAPL we just
* created */
group_id = H5Gopen2(file_id, "plist_link", gapl_id);
/* If we change the value set on the property list, it will change where
* the plist link points.
*/
path = "group_1/group_2";
H5Pset(gapl_id, PLIST_LINK_PROP, &path);
group2_id = H5Gopen2(file_id, "plist_link", gapl_id);
/* group_id points to group_1 and group2_id points to group_2, both opened
* through the same link.
* Using more than one of this type of link could quickly become confusing,
* since they will all use the same property list; however, there is
* nothing to prevent the links from changing the property list in their
* traverse callbacks.
*/
/* Clean up */
H5Pclose(gapl_id);
H5Gclose(group_id);
H5Gclose(group2_id);
H5Fclose(file_id);
}
/*
* Create datasets in the location (in "/" or "/group") with
* message id: (a) H5O_BOGUS_VALID_ID or (b)H5O_BOGUS_INVALID_ID
* and various unknown message flags
*/
static int
generate_datasets(hid_t loc_id, unsigned bogus_id)
{
hid_t sid = -1; /* Dataspace ID */
hid_t dcpl = -1; /* Dataset creation property list ID */
hid_t did = -1; /* Dataset ID */
uint8_t bogus_flags = 0; /* Flags for bogus message */
/* Create dataspace for datasets */
if((sid = H5Screate(H5S_SCALAR)) < 0) goto error;
/* Create dataset creation property list */
if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0) goto error;
/* Add property for bogus message flags */
if(H5Pinsert2(dcpl, H5O_BOGUS_MSG_FLAGS_NAME, H5O_BOGUS_MSG_FLAGS_SIZE, &bogus_flags, NULL, NULL, NULL, NULL, NULL, NULL) < 0) goto error;
/* Add property for bogus message ID */
if(H5Pinsert2(dcpl, H5O_BOGUS_MSG_ID_NAME, H5O_BOGUS_MSG_ID_SIZE, &bogus_id, NULL, NULL, NULL, NULL, NULL, NULL) < 0) goto error;
/* Create dataset with "bogus" message, but no message flags */
if((did = H5Dcreate2(loc_id, "Dataset1", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) goto error;
if(H5Dclose(did) < 0) goto error;
/* Set "fail if unknown and open for write" message flag for bogus message */
bogus_flags = H5O_MSG_FLAG_FAIL_IF_UNKNOWN_AND_OPEN_FOR_WRITE;
if(H5Pset(dcpl, H5O_BOGUS_MSG_FLAGS_NAME, &bogus_flags) < 0) goto error;
/* Create second dataset, with "fail if unknown" message flag */
if((did = H5Dcreate2(loc_id, "Dataset2", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) goto error;
if(H5Dclose(did) < 0) goto error;
/* Set "fail if unknown always" message flag for bogus message */
bogus_flags = H5O_MSG_FLAG_FAIL_IF_UNKNOWN_ALWAYS;
if(H5Pset(dcpl, H5O_BOGUS_MSG_FLAGS_NAME, &bogus_flags) < 0) goto error;
/* Create third dataset, with "fail if unknown always" message flag */
if((did = H5Dcreate2(loc_id, "Dataset3", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) goto error;
if(H5Dclose(did) < 0) goto error;
/* Set "mark if unknown" message flag for bogus message */
bogus_flags = H5O_MSG_FLAG_MARK_IF_UNKNOWN;
if(H5Pset(dcpl, H5O_BOGUS_MSG_FLAGS_NAME, &bogus_flags) < 0) goto error;
/* Create fourth dataset, with "mark if unknown" message flag */
if((did = H5Dcreate2(loc_id, "Dataset4", H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) goto error;
if(H5Dclose(did) < 0) goto error;
/* Close dataset creation property list */
if(H5Pclose(dcpl) < 0) goto error;
/* Close dataspace */
if(H5Sclose(sid) < 0) goto error;
return 0;
error:
H5E_BEGIN_TRY {
H5Dclose(did);
H5Sclose(sid);
H5Pclose(dcpl);
} H5E_END_TRY;
return -1;
} /* generate_datasets() */
