path: root/java/examples/groups/H5Ex_G_Phase.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
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 * 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     *
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 * access to either file, you may request a copy from help@hdfgroup.org.     *
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/************************************************************
  This example shows how to set the conditions for
  conversion between compact and dense (indexed) groups.
 ************************************************************/
package examples.groups;

import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
import hdf.hdf5lib.structs.H5G_info_t;

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

public class H5Ex_G_Phase {
    private static String FILE = "H5Ex_G_Phase.h5";
    private static int MAX_GROUPS = 7;
    private static int MAX_COMPACT = 5;
    private static int MIN_DENSE = 3;

    enum H5G_storage {
        H5G_STORAGE_TYPE_UNKNOWN(-1),
        H5G_STORAGE_TYPE_SYMBOL_TABLE(0),
        H5G_STORAGE_TYPE_COMPACT(1),
        H5G_STORAGE_TYPE_DENSE(2);

        private static final Map<Integer, H5G_storage> lookup = new HashMap<Integer, H5G_storage>();

        static {
            for (H5G_storage s : EnumSet.allOf(H5G_storage.class))
                lookup.put(s.getCode(), s);
        }

        private int code;

        H5G_storage(int layout_type) {
            this.code = layout_type;
        }

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

        public static H5G_storage get(int code) {
            return lookup.get(code);
        }
    }

    private static void CreateGroup() {
        long file_id = -1;
        long group_id = -1;
        long subgroup_id = -1;
        long fapl_id = -1;
        long gcpl_id = -1;
        H5G_info_t ginfo;
        String name = "G0"; // Name of subgroup_id
        int i;

        // Set file access property list to allow the latest file format.This will allow the library to create new
        // format groups.
        try {
            fapl_id = H5.H5Pcreate(HDF5Constants.H5P_FILE_ACCESS);
            if (fapl_id >= 0)
                H5.H5Pset_libver_bounds(fapl_id, HDF5Constants.H5F_LIBVER_LATEST, HDF5Constants.H5F_LIBVER_LATEST);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create group access property list and set the phase change conditions.
        try {
            gcpl_id = H5.H5Pcreate(HDF5Constants.H5P_GROUP_CREATE);
            if (gcpl_id >= 0)
                H5.H5Pset_link_phase_change(gcpl_id, MAX_COMPACT, MIN_DENSE);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create a new file using the default properties.
        try {
            if (fapl_id >= 0)
                file_id = H5.H5Fcreate(FILE, HDF5Constants.H5F_ACC_TRUNC, HDF5Constants.H5P_DEFAULT, fapl_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Create primary group.
        try {
            if ((file_id >= 0) && (gcpl_id >= 0))
                group_id = H5.H5Gcreate(file_id, name, HDF5Constants.H5P_DEFAULT, gcpl_id, HDF5Constants.H5P_DEFAULT);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Add subgroups to "group" one at a time, print the storage type for "group" after each subgroup is created.
        for (i = 1; i <= MAX_GROUPS; i++) {
            // Define the subgroup name and create the subgroup.
            char append = (char) (((char) i) + '0');
            name = name + append; /* G1, G2, G3 etc. */
            try {
                if (group_id >= 0) {
                    subgroup_id = H5.H5Gcreate(group_id, name, HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT,
                            HDF5Constants.H5P_DEFAULT);
                    H5.H5Gclose(subgroup_id);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }

            // Obtain the group info and print the group storage type
            try {
                if (group_id >= 0) {
                    ginfo = H5.H5Gget_info(group_id);
                    System.out.print(ginfo.nlinks + " Group" + (ginfo.nlinks == 1 ? " " : "s") + ": Storage type is ");
                    switch (H5G_storage.get(ginfo.storage_type)) {
                    case H5G_STORAGE_TYPE_COMPACT:
                        System.out.println("H5G_STORAGE_TYPE_COMPACT"); // New compact format
                        break;
                    case H5G_STORAGE_TYPE_DENSE:
                        System.out.println("H5G_STORAGE_TYPE_DENSE"); // New dense (indexed) format
                        break;
                    case H5G_STORAGE_TYPE_SYMBOL_TABLE:
                        System.out.println("H5G_STORAGE_TYPE_SYMBOL_TABLE"); // Original format
                        break;
                    case H5G_STORAGE_TYPE_UNKNOWN:
                        System.out.println("H5G_STORAGE_TYPE_UNKNOWN");
                        break;
                    default:
                        System.out.println("Storage Type Invalid");
                        break;
                    }
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }

        System.out.println();

        // Delete subgroups one at a time, print the storage type for "group" after each subgroup is deleted.
        for (i = MAX_GROUPS; i >= 1; i--) {
            // Define the subgroup name and delete the subgroup.
            try {
                H5.H5Ldelete(group_id, name, HDF5Constants.H5P_DEFAULT);
            }
            catch (Exception e) {
                e.printStackTrace();
            }
            name = name.substring(0, i + 1);

            // Obtain the group info and print the group storage type
            try {
                if (group_id >= 0) {
                    ginfo = H5.H5Gget_info(group_id);
                    System.out.print(ginfo.nlinks + " Group" + (ginfo.nlinks == 1 ? " " : "s") + ": Storage type is ");
                    switch (H5G_storage.get(ginfo.storage_type)) {
                    case H5G_STORAGE_TYPE_COMPACT:
                        System.out.println("H5G_STORAGE_TYPE_COMPACT"); // New compact format
                        break;
                    case H5G_STORAGE_TYPE_DENSE:
                        System.out.println("H5G_STORAGE_TYPE_DENSE"); // New dense (indexed) format
                        break;
                    case H5G_STORAGE_TYPE_SYMBOL_TABLE:
                        System.out.println("H5G_STORAGE_TYPE_SYMBOL_TABLE"); // Original format
                        break;
                    case H5G_STORAGE_TYPE_UNKNOWN:
                        System.out.println("H5G_STORAGE_TYPE_UNKNOWN");
                        break;
                    default:
                        System.out.println("Storage Type Invalid");
                        break;
                    }
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }

        // Close and release resources
        try {
            if (fapl_id >= 0)
                H5.H5Pclose(fapl_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            if (gcpl_id >= 0)
                H5.H5Pclose(gcpl_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Close the group
        try {
            if (group_id >= 0)
                H5.H5Gclose(group_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        // Close the file
        try {
            if (file_id >= 0)
                H5.H5Fclose(file_id);
        }
        catch (Exception e) {
            e.printStackTrace();
        }

    }

    public static void main(String[] args) {
        H5Ex_G_Phase.CreateGroup();
    }

}