/************************************************************ This example shows how to read and write region references to a dataset. The program first creates a dataset containing characters and writes references to region of the dataset to a new dataset with a dataspace of DIM0, then closes the file. Next, it reopens the file, dereferences the references, and outputs the referenced regions to the screen. ************************************************************/ #include "hdf5.h" #include #include #define FILE "h5ex_t_regref.h5" #define DATASET "DS1" #define DATASET2 "DS2" #define DIM0 2 #define DS2DIM0 3 #define DS2DIM1 16 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 dset2 = H5I_INVALID_HID; /* Dataset Handle */ hid_t memspace = H5I_INVALID_HID; /* Mem dataspace */ herr_t status; hsize_t dims[1] = {DIM0}; hsize_t dims2[2] = {DS2DIM0, DS2DIM1}; hsize_t coords[4][2] = {{0, 1}, {2, 11}, {1, 0}, {2, 4}}; hsize_t start[2] = {0, 0}; hsize_t stride[2] = {2, 11}; hsize_t count[2] = {2, 2}; hsize_t block[2] = {1, 3}; hssize_t npoints; ssize_t size; char *name = NULL; int ndims; hsize_t i; char wdata2[DS2DIM0][DS2DIM1] = {"The quick brown", "fox jumps over ", "the 5 lazy dogs"}; char *rdata2 = NULL; #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_DSETREG; /* Reference datatype */ hdset_reg_ref_t wdata[DIM0]; /* Write buffer */ hdset_reg_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); if (file < 0) goto done; /* * Create a dataset with character data. */ space = H5Screate_simple(2, dims2, NULL); dset2 = H5Dcreate(file, DATASET2, H5T_STD_I8LE, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); if (dset2 < 0) goto done; status = H5Dwrite(dset2, H5T_NATIVE_CHAR, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata2); /* * Create reference to a list of elements in dset2. */ status = H5Sselect_elements(space, H5S_SELECT_SET, 4, coords[0]); #if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) status = H5Rcreate_region(file, DATASET2, space, H5P_DEFAULT, &wdata[0]); #else status = H5Rcreate(&wdata[0], file, DATASET2, H5R_DATASET_REGION, space); #endif if (status < 0) goto done; /* * Create reference to a hyperslab in dset2, close dataspace. */ status = H5Sselect_hyperslab(space, H5S_SELECT_SET, start, stride, count, block); #if H5_VERSION_GE(1, 12, 0) && !defined(H5_USE_110_API) && !defined(H5_USE_18_API) && !defined(H5_USE_16_API) status = H5Rcreate_region(file, DATASET2, space, H5P_DEFAULT, &wdata[1]); #else status = H5Rcreate(&wdata[1], file, DATASET2, H5R_DATASET_REGION, space); #endif if (status < 0) goto done; status = H5Sclose(space); /* * Create dataspace. Setting maximum size to NULL sets the maximum * size to be the current size. */ space = H5Screate_simple(1, dims, NULL); /* * Create the dataset and write the region references to it. */ dset = H5Dcreate(file, DATASET, ref_type, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); if (dset < 0) goto done; 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 = H5Dclose(dset2); 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); if (file < 0) goto done; dset = H5Dopen(file, DATASET, H5P_DEFAULT); if (dset < 0) goto done; /* * 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 = (hdset_reg_ref_t *)malloc(dims[0] * sizeof(hdset_reg_ref_t)); #endif status = H5Sclose(space); /* * 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[%" PRIuHSIZE "]:\n ->", DATASET, i); /* * Open the referenced object, retrieve its region as a * dataspace selection. */ #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) dset2 = H5Ropen_object(&rdata[i], H5P_DEFAULT, H5P_DEFAULT); space = H5Ropen_region(&rdata[i], H5P_DEFAULT, H5P_DEFAULT); #else dset2 = H5Rdereference(dset, H5P_DEFAULT, H5R_DATASET_REGION, &rdata[i]); space = H5Rget_region(dset, H5R_DATASET_REGION, &rdata[i]); #endif #else dset2 = H5Rdereference(dset, H5R_DATASET_REGION, &rdata[i]); space = H5Rget_region(dset, H5R_DATASET_REGION, &rdata[i]); #endif if (dset2 < 0) goto done; /* * Get the length of the object's name, allocate space, then * retrieve the name. */ size = 1 + H5Iget_name(dset2, NULL, 0); name = (char *)malloc(size); size = H5Iget_name(dset2, name, size); /* * Allocate space for the read buffer. We will only allocate * enough space for the selection, plus a null terminator. The * read buffer will be 1-dimensional. */ npoints = H5Sget_select_npoints(space); rdata2 = (char *)malloc(npoints + 1); /* * Read the dataset region, and add a null terminator so we can * print it as a string. */ memspace = H5Screate_simple(1, (hsize_t *)&npoints, NULL); status = H5Dread(dset2, H5T_NATIVE_CHAR, memspace, space, H5P_DEFAULT, rdata2); rdata2[npoints] = '\0'; /* * Print the name and region data, close and release resources. */ printf(" %s: %s\n", name, rdata2); free(rdata2); 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 status = H5Sclose(space); status = H5Sclose(memspace); status = H5Dclose(dset2); } /* * Close and release resources. */ free(rdata); status = H5Dclose(dset); status = H5Fclose(file); return 0; done: return 1; }