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Diffstat (limited to 'examples/h5_vds-simpleIO.c')
| -rw-r--r-- | examples/h5_vds-simpleIO.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/examples/h5_vds-simpleIO.c b/examples/h5_vds-simpleIO.c new file mode 100644 index 0000000..b707ae4 --- /dev/null +++ b/examples/h5_vds-simpleIO.c @@ -0,0 +1,184 @@ +/************************************************************ + + This example illustrates the concept of virtual dataset I/O + The program creates 2-dim source dataset and writes + data to it. Then it creates 2-dim virtual dataset that has + the same dimesnion sizes and maps the all elements of the + virtual dataset to all elements of the source dataset. + Then VDS is read back. + + This file is intended for use with HDF5 Library version 1.10 + + ************************************************************/ +/* EIP Add link to the picture */ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "vds-simpleIO.h5" +#define DATASET "VDS" +#define DIM1 6 +#define DIM0 4 +#define RANK 2 + +#define SRC_FILE "a.h5" +#define SRC_DATASET "/A" + + +int +main (void) +{ + hid_t file, space, src_space, vspace, dset; /* Handles */ + hid_t dcpl; + herr_t status; + hsize_t vdsdims[2] = {DIM0, DIM1}, /* Virtual dataset dimension */ + dims[2] = {DIM0, DIM1}; /* Source dataset dimensions */ + int wdata[DIM0][DIM1], /* Write buffer for source dataset */ + rdata[DIM0][DIM1], /* Read buffer for virtual dataset */ + i, j; + H5D_layout_t layout; /* Storage layout */ + size_t num_map; /* Number of mappings */ + ssize_t len; /* Length of the string; also a return value */ + char *filename; + char *dsetname; + /* + * Initialize data. + */ + for (i = 0; i < DIM0; i++) + for (j = 0; j < DIM1; j++) wdata[i][j] = i+1; + + /* + * Create the source file and the dataset. Write data to the source dataset + * and close all resources. + */ + + file = H5Fcreate (SRC_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + space = H5Screate_simple (RANK, dims, NULL); + dset = H5Dcreate2 (file, SRC_DATASET, H5T_NATIVE_INT, space, H5P_DEFAULT, + H5P_DEFAULT, H5P_DEFAULT); + status = H5Dwrite (dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, + wdata[0]); + 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. */ + vspace = H5Screate_simple (RANK, vdsdims, NULL); + + /* Set VDS creation property. */ + dcpl = H5Pcreate (H5P_DATASET_CREATE); + + /* + * 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 (RANK, dims, NULL); + status = H5Pset_virtual (dcpl, vspace, SRC_FILE, SRC_DATASET, src_space); + + /* Create a virtual dataset. */ + dset = H5Dcreate2 (file, DATASET, H5T_NATIVE_INT, vspace, H5P_DEFAULT, + dcpl, H5P_DEFAULT); + status = H5Sclose (vspace); + status = H5Sclose (src_space); + status = H5Dclose (dset); + status = H5Fclose (file); + + /* + * Now we begin the read section of this example. + */ + + /* + * Open the file and virtual dataset. + */ + 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 virttual dataset */ + vspace = H5Pget_virtual_vspace (dcpl, (size_t)i); + + /* Make sure it is ALL selection and then print selection. */ + if(H5Sget_select_type(vspace) == H5S_SEL_ALL) { + printf("Selection is H5S_ALL \n"); + } + /* 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 selection. */ + if(H5Sget_select_type(src_space) == H5S_SEL_ALL) { + printf("Selection is H5S_ALL \n"); + } + H5Sclose(vspace); + H5Sclose(src_space); + free(filename); + free(dsetname); + } + /* + * 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<DIM0; i++) { + printf (" ["); + for (j=0; j<DIM1; j++) + printf (" %3d", rdata[i][j]); + printf ("]\n"); + } + /* + * Close and release resources. + */ + status = H5Pclose (dcpl); + status = H5Dclose (dset); + status = H5Fclose (file); + + return 0; +} + |