mirror of
https://github.com/HDFGroup/hdf5.git
synced 2024-11-27 02:10:55 +08:00
268 lines
9.9 KiB
C
268 lines
9.9 KiB
C
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
|
|
* Copyright by The HDF Group. *
|
|
* Copyright by the Board of Trustees of the University of Illinois. *
|
|
* 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 files COPYING and Copyright.html. COPYING can be found at the root *
|
|
* of the source code distribution tree; Copyright.html can be found at the *
|
|
* root level of an installed copy of the electronic HDF5 document set and *
|
|
* is linked from the top-level documents page. It can also be found at *
|
|
* http://hdfgroup.org/HDF5/doc/Copyright.html. 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
|
|
|
|
************************************************************/
|
|
/* EIP Add link to the picture */
|
|
|
|
#include "hdf5.h"
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#define FILE "vds.h5"
|
|
#define DATASET "VDS"
|
|
#define VDSDIM1 6
|
|
#define VDSDIM0 4
|
|
#define DIM0 6
|
|
#define RANK1 1
|
|
#define RANK2 2
|
|
|
|
const char *SRC_FILE[] = {
|
|
"a.h5",
|
|
"b.h5",
|
|
"c.h5"
|
|
};
|
|
|
|
const char *SRC_DATASET[] = {
|
|
"A",
|
|
"B",
|
|
"C"
|
|
};
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
hid_t file, space, src_space, vspace, dset; /* Handles */
|
|
hid_t dcpl;
|
|
herr_t status;
|
|
hsize_t vdsdims[2] = {VDSDIM0, VDSDIM1}, /* Virtual datasets dimension */
|
|
dims[1] = {DIM0}, /* Source datasets dimensions */
|
|
start[2], /* Hyperslab parameters */
|
|
stride[2],
|
|
count[2],
|
|
block[2];
|
|
hsize_t start_out[2],
|
|
stride_out[2],
|
|
count_out[2],
|
|
block_out[2];
|
|
int wdata[DIM0], /* Write buffer for source dataset */
|
|
rdata[VDSDIM0][VDSDIM1], /* Read buffer for virtual dataset */
|
|
i, j, k, l;
|
|
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 */
|
|
char *filename;
|
|
char *dsetname;
|
|
hsize_t nblocks;
|
|
hsize_t *buf; /* Buffer to hold hyperslab coordinates */
|
|
|
|
/*
|
|
* 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 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 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++) {
|
|
printf("(");
|
|
for (k=0; k<RANK2-1; k++)
|
|
printf("%d,", (int)buf[k]);
|
|
printf("%d ) - (", (int)buf[k]);
|
|
for (k=0; k<RANK2-1; k++)
|
|
printf("%d,", (int)buf[RANK2+k]);
|
|
printf("%d)\n", (int)buf[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;
|
|
}
|
|
|