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Diffstat (limited to 'HDF5Examples/C/H5T/h5ex_t_objref.c')
| -rw-r--r-- | HDF5Examples/C/H5T/h5ex_t_objref.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5T/h5ex_t_objref.c b/HDF5Examples/C/H5T/h5ex_t_objref.c new file mode 100644 index 0000000..1109720 --- /dev/null +++ b/HDF5Examples/C/H5T/h5ex_t_objref.c @@ -0,0 +1,203 @@ +/************************************************************ + + This example shows how to read and write object references + to a dataset. The program first creates objects in the + file and writes references to those objects to a dataset + with a dataspace of DIM0, then closes the file. Next, it + reopens the file, dereferences the references, and outputs + the names of their targets to the screen. + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_t_objref.h5" +#define DATASET "DS1" +#define DIM0 2 +#define RANK 1 + +int +main(void) +{ + hid_t file = H5I_INVALID_HID; /* File Handle */ + hid_t space = H5I_INVALID_HID; /* Dataspace Handle */ + hid_t dset = H5I_INVALID_HID; /* Dataset Handle */ + hid_t obj = H5I_INVALID_HID; /* Object Handle */ + herr_t status; + hsize_t dims[1] = {DIM0}; + ssize_t size; + char *name = NULL; + int ndims; + hsize_t i; + +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + hid_t ref_type = H5T_STD_REF; /* Reference datatype */ + H5R_ref_t wdata[DIM0]; /* buffer to write to disk */ + H5R_ref_t *rdata = NULL; /* buffer to read into*/ + H5R_type_t objtype; /* Reference type */ +#else + hid_t ref_type = H5T_STD_REF_OBJ; /* Reference datatype */ + hobj_ref_t wdata[DIM0]; /* Write buffer */ + hobj_ref_t *rdata = NULL; /* Read buffer */ + H5O_type_t objtype; +#endif + + /* + * Create a new file using the default properties. + */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* + * Create a dataset with a null dataspace. + */ + space = H5Screate(H5S_NULL); + obj = H5Dcreate(file, "DS2", H5T_STD_I32LE, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + status = H5Dclose(obj); + status = H5Sclose(space); + + /* + * Create a group. + */ + obj = H5Gcreate(file, "G1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + status = H5Gclose(obj); + + /* + * Create dataspace. Setting maximum size to NULL sets the maximum + * size to be the current size. + */ + space = H5Screate_simple(RANK, dims, NULL); + + /* + * Create references to the previously created objects. + */ +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + status = H5Rcreate_object(file, "G1", H5R_OBJECT, &wdata[0]); + status = H5Rcreate_object(file, "DS2", H5R_OBJECT, &wdata[1]); +#else + /* + * Passing -1 + * as space_id causes this parameter to be ignored. Other values + * besides valid dataspaces result in an error. + */ + status = H5Rcreate(&wdata[0], file, "G1", H5R_OBJECT, -1); + status = H5Rcreate(&wdata[1], file, "DS2", H5R_OBJECT, -1); +#endif + + /* + * Create the dataset and write the object references to it. + */ + dset = H5Dcreate(file, DATASET, ref_type, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + status = H5Dwrite(dset, ref_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata); + + /* + * Close and release resources. + */ +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + status = H5Rdestroy(&wdata[0]); + status = H5Rdestroy(&wdata[1]); +#endif + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Fclose(file); + + /* + * Now we begin the read section of this example. Here we assume + * the dataset has the same name and rank, but can have any size. + * Therefore we must allocate a new array to read in data using + * malloc(). + */ + + /* + * Open file and dataset. + */ + file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dset = H5Dopen(file, DATASET, H5P_DEFAULT); + + /* + * Get dataspace and allocate memory for read buffer. + */ + space = H5Dget_space(dset); + ndims = H5Sget_simple_extent_dims(space, dims, NULL); + +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + rdata = (H5R_ref_t *)malloc(dims[0] * sizeof(H5R_ref_t)); +#else + rdata = (hobj_ref_t *)malloc(dims[0] * sizeof(hobj_ref_t)); +#endif + /* + * Read the data. + */ + status = H5Dread(dset, ref_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata); + + /* + * Output the data to the screen. + */ + for (i = 0; i < dims[0]; i++) { + printf("%s[%llu]:\n ->", DATASET, i); + + /* + * Open the referenced object, get its name and type. + */ +#if H5_VERSION_GE(1, 10, 0) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + obj = H5Ropen_object(&rdata[i], H5P_DEFAULT, H5P_DEFAULT); + status = H5Rget_obj_type3(&rdata[i], H5P_DEFAULT, &objtype); +#else + obj = H5Rdereference(dset, H5P_DEFAULT, H5R_OBJECT, &rdata[i]); + status = H5Rget_obj_type(dset, H5R_OBJECT, &rdata[i], &objtype); +#endif +#else + obj = H5Rdereference(dset, H5R_OBJECT, &rdata[i]); + status = H5Rget_obj_type(dset, H5R_OBJECT, &rdata[i], &objtype); +#endif + + /* + * Get the length of the name, allocate space, then retrieve + * the name. + */ + size = 1 + H5Iget_name(obj, NULL, 0); + name = (char *)malloc(size); + size = H5Iget_name(obj, name, size); + + /* + * Print the object type and close the object. + */ + switch (objtype) { + case H5O_TYPE_GROUP: + printf("Group"); + break; + case H5O_TYPE_DATASET: + printf("Dataset"); + break; + case H5O_TYPE_NAMED_DATATYPE: + printf("Named Datatype"); + break; + case H5O_TYPE_UNKNOWN: + case H5O_TYPE_NTYPES: + printf("Unknown"); + } + status = H5Oclose(obj); + + /* + * Print the name and deallocate space for the name. + */ + printf(": %s\n", name); + free(name); + +#if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) + status = H5Rdestroy(&rdata[i]); +#endif + } + + /* + * Close and release resources. + */ + free(rdata); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Fclose(file); + + return 0; +} |