/************************************************************
  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 DIM_XxDIM_Y, then
  closes the file.  Next, it reopens the file, reads back
  the data, and outputs it to the screen.
 ************************************************************/
package examples.datasets;

import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;

import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
import hdf.object.Dataset;
import hdf.object.Datatype;
import hdf.object.FileFormat;
import hdf.object.Group;
import hdf.object.h5.H5Datatype;
import hdf.object.h5.H5File;
import hdf.object.h5.H5ScalarDS;

public class H5ObjectEx_D_Compact {
    private static String FILENAME = "H5ObjectEx_D_Compact.h5";
    private static String DATASETNAME = "DS1";
    private static final int DIM_X = 4;
    private static final int DIM_Y = 7;
    private static final int RANK = 2;
    private static final int DATATYPE_SIZE = 4;

    // Values for the status of space allocation
    enum H5D_layout {
        H5D_LAYOUT_ERROR(-1), H5D_COMPACT(0), H5D_CONTIGUOUS(1), H5D_CHUNKED(2), H5D_NLAYOUTS(
                3);
        private static final Map<Integer, H5D_layout> lookup = new HashMap<Integer, H5D_layout>();

        static {
            for (H5D_layout s : EnumSet.allOf(H5D_layout.class))
                lookup.put(s.getCode(), s);
        }

        private int code;

        H5D_layout(int layout_type) {
            this.code = layout_type;
        }

        public int getCode() {
            return this.code;
        }

        public static H5D_layout get(int code) {
            return lookup.get(code);
        }
    }

    private static void writeCompact() {
        H5File file = null;
        Dataset dset = null;
        long file_id = -1;
        long filespace_id = -1;
        long dataset_id = -1;
        long dcpl_id = -1;
        long type_id = -1;
        long[] dims = { DIM_X, DIM_Y };
        int[][] dset_data = new int[DIM_X][DIM_Y];
        final H5Datatype typeInt = new H5Datatype(Datatype.CLASS_INTEGER,
                DATATYPE_SIZE, Datatype.ORDER_LE, -1);

        // Initialize data.
        for (int indx = 0; indx < DIM_X; indx++)
            for (int jndx = 0; jndx < DIM_Y; jndx++)
                dset_data[indx][jndx] = indx * jndx - jndx;

        // Create a new file using default properties.
        try {
            file = new H5File(FILENAME, FileFormat.CREATE);
            file_id = file.open();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create dataspace. Setting maximum size to NULL sets the maximum
        // size to be the current size.
        try {
            filespace_id = H5.H5Screate_simple(RANK, dims, null);
            type_id = typeInt.createNative();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create the dataset creation property list.
        try {
            dcpl_id = H5.H5Pcreate(HDF5Constants.H5P_DATASET_CREATE);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Set the layout to compact.
        try {
            if (dcpl_id >= 0)
                H5.H5Pset_layout(dcpl_id, H5D_layout.H5D_COMPACT.getCode());
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create the dataset. We will use all default properties for this example.
        try {
            if ((file_id >= 0) && (filespace_id >= 0) && (dcpl_id >= 0))
                dataset_id = H5.H5Dcreate(file_id, DATASETNAME,
                        type_id, filespace_id, HDF5Constants.H5P_DEFAULT, dcpl_id, HDF5Constants.H5P_DEFAULT);
            dset = new H5ScalarDS(file, DATASETNAME, "/");
            Group pgroup = (Group) file.get("/");
            pgroup.addToMemberList(dset);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Write the data to the dataset.
        try {
            dset.write(dset_data);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // End access to the dataset and release resources used by it.
        try {
            if (dcpl_id >= 0)
                H5.H5Pclose(dcpl_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (type_id >= 0)
                H5.H5Tclose(type_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (dataset_id >= 0)
                dset.close(dataset_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (filespace_id >= 0)
                H5.H5Sclose(filespace_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Close the file.
        try {
            file.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void readCompact() {
        H5File file = null;
        Dataset dset = null;
        long filespace_id = -1;
        long dataset_id = -1;
        long dcpl_id = -1;
        int[] dset_data = new int[DIM_X*DIM_Y];

        // Open file and dataset using the default properties.
        try {
            file = new H5File(FILENAME, FileFormat.READ);
            file.open();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Open an existing dataset.
        try {
            dset = (Dataset) file.get(DATASETNAME);
            dataset_id = dset.open();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Retrieve the dataset creation property list.
        try {
            if (dataset_id >= 0)
                dcpl_id = H5.H5Dget_create_plist(dataset_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Print the storage layout.
        try {
            if (dcpl_id >= 0) {
                int layout_type = H5.H5Pget_layout(dcpl_id);
                System.out.print("Storage layout for " + DATASETNAME + " is: ");
                switch (H5D_layout.get(layout_type)) {
                    case H5D_COMPACT:
                        System.out.println("H5D_COMPACT");
                        break;
                    case H5D_CONTIGUOUS:
                        System.out.println("H5D_CONTIGUOUS");
                        break;
                    case H5D_CHUNKED:
                        System.out.println("H5D_CHUNKED");
                        break;
                }
                System.out.println();
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Read the data using the default properties.
        try {
            dset.init();
            dset_data = (int[]) dset.getData();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Output the data to the screen.
        System.out.println("Data for " + DATASETNAME + " is: ");
        for (int indx = 0; indx < DIM_X; indx++) {
            System.out.print(" [ ");
            for (int jndx = 0; jndx < DIM_Y; jndx++)
                System.out.print(dset_data[indx*DIM_Y+jndx] + " ");
            System.out.println("]");
        }
        System.out.println();

        // End access to the dataset and release resources used by it.
        try {
            if (dcpl_id >= 0)
                H5.H5Pclose(dcpl_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (dataset_id >= 0)
                dset.close(dataset_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (filespace_id >= 0)
                H5.H5Sclose(filespace_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Close the file.
        try {
            file.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        H5ObjectEx_D_Compact.writeCompact();
        H5ObjectEx_D_Compact.readCompact();
    }

}