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Diffstat (limited to 'HDF5Examples/C/H5VDS/h5ex_vds.c')
| -rw-r--r-- | HDF5Examples/C/H5VDS/h5ex_vds.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5VDS/h5ex_vds.c b/HDF5Examples/C/H5VDS/h5ex_vds.c new file mode 100644 index 0000000..96a8137 --- /dev/null +++ b/HDF5Examples/C/H5VDS/h5ex_vds.c @@ -0,0 +1,254 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * 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. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ +/************************************************************ + + This example illustrates the concept of virtual dataset. + The program creates three 1-dim source datasets and writes + data to them. Then it creates a 2-dim virtual dataset and + maps the first three rows of the virtual dataset to the data + in the source datasets. Elements of a row are mapped to all + elements of the corresponding source dataset. + The fourth row is not mapped and will be filled with the fill + values when virtual dataset is read back. + + The program closes all datasets, and then reopens the virtual + dataset, and finds and prints its creation properties. + Then it reads the values. + + This file is intended for use with HDF5 Library version 1.10 + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_vds.h5" +#define DATASET "VDS" +#define VDSDIM1 6 +#define VDSDIM0 4 +#define DIM0 6 +#define RANK1 1 +#define RANK2 2 + +const char *SRC_FILE[] = {"h5ex_vds_a.h5", "h5ex_vds_b.h5", "h5ex_vds_c.h5"}; + +const char *SRC_DATASET[] = {"A", "B", "C"}; + +int +main(void) +{ + hid_t file = H5I_INVALID_HID; + hid_t space = H5I_INVALID_HID; + hid_t dset = H5I_INVALID_HID; + hid_t src_space = H5I_INVALID_HID; + hid_t vspace = H5I_INVALID_HID; + hid_t dcpl = H5I_INVALID_HID; + herr_t status; + hsize_t vdsdims[2] = {VDSDIM0, VDSDIM1}; /* Virtual datasets dimension */ + hsize_t dims[1] = {DIM0}; /* Source datasets dimensions */ + hsize_t start[2], count[2], block[2]; /* Hyperslab parameters */ + hsize_t start_out[2], stride_out[2], count_out[2], block_out[2]; + int wdata[DIM0]; /* Write buffer for source dataset */ + int rdata[VDSDIM0][VDSDIM1]; /* Read buffer for virtual dataset */ + int i, j, k, l, block_inc; + int fill_value = -1; /* Fill value for VDS */ + H5D_layout_t layout; /* Storage layout */ + size_t num_map; /* Number of mappings */ + ssize_t len; /* Length of the string; also a return value */ + hsize_t *buf = NULL; /* Buffer to hold hyperslab coordinates */ + char *filename = NULL; + char *dsetname = NULL; + hsize_t nblocks; + + /* + * Create source files and datasets. This step is optional. + */ + for (i = 0; i < 3; i++) { + /* + * Initialize data for i-th source dataset. + */ + for (j = 0; j < DIM0; j++) + wdata[j] = i + 1; + + /* + * Create the source files and datasets. Write data to each dataset and + * close all resources. + */ + + file = H5Fcreate(SRC_FILE[i], H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + space = H5Screate_simple(RANK1, dims, NULL); + dset = H5Dcreate2(file, SRC_DATASET[i], H5T_NATIVE_INT, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata); + status = H5Sclose(space); + status = H5Dclose(dset); + status = H5Fclose(file); + } + + /* Create file in which virtual dataset will be stored. */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* Create VDS dataspace. */ + space = H5Screate_simple(RANK2, vdsdims, NULL); + + /* Set VDS creation property. */ + dcpl = H5Pcreate(H5P_DATASET_CREATE); + status = H5Pset_fill_value(dcpl, H5T_NATIVE_INT, &fill_value); + + /* Initialize hyperslab values. */ + start[0] = 0; + start[1] = 0; + count[0] = 1; + count[1] = 1; + block[0] = 1; + block[1] = VDSDIM1; + + /* + * Build the mappings. + * Selections in the source datasets are H5S_ALL. + * In the virtual dataset we select the first, the second and the third rows + * and map each row to the data in the corresponding source dataset. + */ + src_space = H5Screate_simple(RANK1, dims, NULL); + for (i = 0; i < 3; i++) { + start[0] = (hsize_t)i; + /* Select i-th row in the virtual dataset; selection in the source datasets is the same. */ + status = H5Sselect_hyperslab(space, H5S_SELECT_SET, start, NULL, count, block); + status = H5Pset_virtual(dcpl, space, SRC_FILE[i], SRC_DATASET[i], src_space); + } + + /* Create a virtual dataset. */ + dset = H5Dcreate2(file, DATASET, H5T_NATIVE_INT, space, H5P_DEFAULT, dcpl, H5P_DEFAULT); + status = H5Sclose(space); + status = H5Sclose(src_space); + status = H5Dclose(dset); + status = H5Fclose(file); + + /* + * Now we begin the read section of this example. + */ + + /* + * Open file and dataset using the default properties. + */ + file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dset = H5Dopen2(file, DATASET, H5P_DEFAULT); + + /* + * Get creation property list and mapping properties. + */ + dcpl = H5Dget_create_plist(dset); + + /* + * Get storage layout. + */ + layout = H5Pget_layout(dcpl); + if (H5D_VIRTUAL == layout) + printf(" Dataset has a virtual layout \n"); + else + printf("Wrong layout found \n"); + + /* + * Find the number of mappings. + */ + status = H5Pget_virtual_count(dcpl, &num_map); + printf(" Number of mappings is %lu\n", (unsigned long)num_map); + + /* + * Get mapping parameters for each mapping. + */ + for (i = 0; i < (int)num_map; i++) { + printf(" Mapping %d \n", i); + printf(" Selection in the virtual dataset "); + /* Get selection in the virtual dataset */ + vspace = H5Pget_virtual_vspace(dcpl, (size_t)i); + + /* Make sure that this is a hyperslab selection and then print information. */ + if (H5Sget_select_type(vspace) == H5S_SEL_HYPERSLABS) { + nblocks = H5Sget_select_hyper_nblocks(vspace); + buf = (hsize_t *)malloc(sizeof(hsize_t) * 2 * RANK2 * nblocks); + status = H5Sget_select_hyper_blocklist(vspace, (hsize_t)0, nblocks, buf); + for (l = 0; l < nblocks; l++) { + block_inc = 2 * RANK2 * l; + printf("("); + for (k = 0; k < RANK2 - 1; k++) + printf("%d,", (int)buf[block_inc + k]); + printf("%d) - (", (int)buf[block_inc + k]); + for (k = 0; k < RANK2 - 1; k++) + printf("%d,", (int)buf[block_inc + RANK2 + k]); + printf("%d)\n", (int)buf[block_inc + RANK2 + k]); + } + /* We also can use new APIs to get start, stride, count and block */ + if (H5Sis_regular_hyperslab(vspace)) { + status = H5Sget_regular_hyperslab(vspace, start_out, stride_out, count_out, block_out); + printf(" start = [%llu, %llu] \n", (unsigned long long)start_out[0], + (unsigned long long)start_out[1]); + printf(" stride = [%llu, %llu] \n", (unsigned long long)stride_out[0], + (unsigned long long)stride_out[1]); + printf(" count = [%llu, %llu] \n", (unsigned long long)count_out[0], + (unsigned long long)count_out[1]); + printf(" block = [%llu, %llu] \n", (unsigned long long)block_out[0], + (unsigned long long)block_out[1]); + } + } + /* Get source file name */ + len = H5Pget_virtual_filename(dcpl, (size_t)i, NULL, 0); + filename = (char *)malloc((size_t)len * sizeof(char) + 1); + H5Pget_virtual_filename(dcpl, (size_t)i, filename, len + 1); + printf(" Source filename %s\n", filename); + + /* Get source dataset name */ + len = H5Pget_virtual_dsetname(dcpl, (size_t)i, NULL, 0); + dsetname = (char *)malloc((size_t)len * sizeof(char) + 1); + H5Pget_virtual_dsetname(dcpl, (size_t)i, dsetname, len + 1); + printf(" Source dataset name %s\n", dsetname); + + /* Get selection in the source dataset */ + printf(" Selection in the source dataset "); + src_space = H5Pget_virtual_srcspace(dcpl, (size_t)i); + + /* Make sure it is ALL selection and then print the coordinates. */ + if (H5Sget_select_type(src_space) == H5S_SEL_ALL) { + printf("(0) - (%d) \n", DIM0 - 1); + } + H5Sclose(vspace); + H5Sclose(src_space); + free(filename); + free(dsetname); + free(buf); + } + + /* + * Read the data using the default properties. + */ + status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata[0]); + + /* + * Output the data to the screen. + */ + printf(" VDS Data:\n"); + for (i = 0; i < VDSDIM0; i++) { + printf(" ["); + for (j = 0; j < VDSDIM1; j++) + printf(" %3d", rdata[i][j]); + printf("]\n"); + } + + /* + * Close and release resources. + */ + status = H5Pclose(dcpl); + status = H5Dclose(dset); + status = H5Fclose(file); + + return 0; +} |