/************************************************************

  This example shows how to read and write data to a compact
  dataset.  The program first writes integers to a compact
  dataset with dataspace dimensions of DIM0xDIM1, then
  closes the file.  Next, it reopens the file, reads back
  the data, and outputs it to the screen.

  This file is intended for use with HDF5 Library version 1.8

 ************************************************************/

#include "hdf5.h"
#include <stdio.h>
#include <stdlib.h>

#define FILE            "h5ex_d_compact.h5"
#define DATASET         "DS1"
#define DIM0            4
#define DIM1            7

int
main (void)
{
    hid_t       file, space, dset, dcpl;    /* Handles */
    herr_t      status;
    H5D_layout_t    layout;
    hsize_t     dims[2] = {DIM0, DIM1};
    int         wdata[DIM0][DIM1],          /* Write buffer */
                rdata[DIM0][DIM1],          /* Read buffer */
                i, j;

    /*
     * Initialize data.
     */
    for (i=0; i<DIM0; i++)
        for (j=0; j<DIM1; j++)
            wdata[i][j] = i * j - j;

    /*
     * Create a new file using the default properties.
     */
    file = H5Fcreate (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /*
     * Create dataspace.  Setting maximum size to NULL sets the maximum
     * size to be the current size.
     */
    space = H5Screate_simple (2, dims, NULL);

    /*
     * Create the dataset creation property list, set the layout to
     * compact.
     */
    dcpl = H5Pcreate (H5P_DATASET_CREATE);
    status = H5Pset_layout (dcpl, H5D_COMPACT);

    /*
     * Create the dataset.  We will use all default properties for this
     * example.
     */
    dset = H5Dcreate (file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, dcpl,
                H5P_DEFAULT);

    /*
     * Write the data to the dataset.
     */
    status = H5Dwrite (dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
                wdata[0]);

    /*
     * Close and release resources.
     */
    status = H5Pclose (dcpl);
    status = H5Dclose (dset);
    status = H5Sclose (space);
    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 = H5Dopen (file, DATASET, H5P_DEFAULT);

    /*
     * Retrieve the dataset creation property list, and print the
     * storage layout.
     */
    dcpl = H5Dget_create_plist (dset);
    layout = H5Pget_layout (dcpl);
    printf ("Storage layout for %s is: ", DATASET);
    switch (layout) {
        case H5D_COMPACT:
            printf ("H5D_COMPACT\n");
            break;
        case H5D_CONTIGUOUS:
            printf ("H5D_CONTIGUOUS\n");
            break;
        case H5D_CHUNKED:
            printf ("H5D_CHUNKED\n");
            break;
        case H5D_VIRTUAL:
            printf ("H5D_VIRTUAL\n");
            break;
        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
            printf ("H5D_LAYOUT_ERROR\n");
    }

    /*
     * 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 ("%s:\n", DATASET);
    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;
}
