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

  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 1.6

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

#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  = H5I_INVALID_HID;
    hid_t        space = H5I_INVALID_HID;
    hid_t        dset  = H5I_INVALID_HID;
    hid_t        dcpl  = H5I_INVALID_HID;
    herr_t       status;
    H5D_layout_t layout;
    hsize_t      dims[2] = {DIM0, DIM1};
    int          wdata[DIM0][DIM1]; /* Write buffer */
    int          rdata[DIM0][DIM1]; /* Read buffer */
    hsize_t      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, dcpl);

    /*
     * 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);

    /*
     * 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");
    }

    /*
     * 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;
}