/************************************************************
  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 ncsa.hdf.hdf5lib.H5;
import ncsa.hdf.hdf5lib.HDF5Constants;
import ncsa.hdf.object.Dataset;
import ncsa.hdf.object.Datatype;
import ncsa.hdf.object.FileFormat;
import ncsa.hdf.object.Group;
import ncsa.hdf.object.h5.H5Datatype;
import ncsa.hdf.object.h5.H5File;
import ncsa.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;
		int file_id = -1;
		int filespace_id = -1;
		int dataset_id = -1;
		int dcpl_id = -1;
        int 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.toNative();
		}
		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;
		int filespace_id = -1;
		int dataset_id = -1;
		int 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();
	}

}