awips2/nativeLib/rary.cots.hdf5/examples/datasets/H5Ex_D_Shuffle.java
root 06a8b51d6d Initial revision of AWIPS2 11.9.0-7p5
Former-commit-id: 64fa9254b946eae7e61bbc3f513b7c3696c4f54f
2012-01-06 08:55:05 -06:00

360 lines
9.3 KiB
Java

/************************************************************
This example shows how to read and write data to a dataset
using the shuffle filter with gzip compression. The
program first checks if the shuffle and gzip filters are
available, then if they are it writes integers to a
dataset using shuffle+gzip, then closes the file. Next,
it reopens the file, reads back the data, and outputs the
types of filters and the maximum value in the dataset to
the screen.
This file is intended for use with HDF5 Library verion 1.6
************************************************************/
package datasets;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import ncsa.hdf.hdf5lib.H5;
import ncsa.hdf.hdf5lib.HDF5Constants;
public class H5Ex_D_Shuffle {
private static String FILENAME = "h5ex_d_shuffle.h5";
private static String DATASETNAME = "DS1";
private static final int DIM_X = 32;
private static final int DIM_Y = 64;
private static final int CHUNK_X = 4;
private static final int CHUNK_Y = 8;
private static final int RANK = 2;
private static final int NDIMS = 2;
// Values for the status of space allocation
enum H5Z_filter {
H5Z_FILTER_ERROR(-1), H5Z_FILTER_NONE(0), H5Z_FILTER_DEFLATE(1), H5Z_FILTER_SHUFFLE(
2), H5Z_FILTER_FLETCHER32(3), H5Z_FILTER_SZIP(4), H5Z_FILTER_NBIT(5), H5Z_FILTER_SCALEOFFSET(
6), H5Z_FILTER_RESERVED(256), H5Z_FILTER_MAX(65535);
private static final Map<Integer, H5Z_filter> lookup = new HashMap<Integer, H5Z_filter>();
static {
for (H5Z_filter s : EnumSet.allOf(H5Z_filter.class))
lookup.put(s.getCode(), s);
}
private int code;
H5Z_filter(int layout_type) {
this.code = layout_type;
}
public int getCode() {
return this.code;
}
public static H5Z_filter get(int code) {
return lookup.get(code);
}
}
private static boolean checkGzipFilter() {
try {
int available = H5.H5Zfilter_avail(H5Z_filter.H5Z_FILTER_DEFLATE
.getCode());
if (available == 0) {
System.out.println("gzip filter not available.");
return false;
}
}
catch (Exception e) {
e.printStackTrace();
}
try {
int filter_info = H5.H5Zget_filter_info(HDF5Constants.H5Z_FILTER_DEFLATE);
if (((filter_info & HDF5Constants.H5Z_FILTER_CONFIG_ENCODE_ENABLED) == 0)
|| ((filter_info & HDF5Constants.H5Z_FILTER_CONFIG_DECODE_ENABLED) == 0)) {
System.out
.println("gzip filter not available for encoding and decoding.");
return false;
}
}
catch (Exception e) {
e.printStackTrace();
}
return true;
}
private static boolean checkShuffleFilter() {
try {
int available = H5.H5Zfilter_avail(H5Z_filter.H5Z_FILTER_SHUFFLE
.getCode());
if (available == 0) {
System.out.println("Shuffle filter not available.");
return false;
}
}
catch (Exception e) {
e.printStackTrace();
}
try {
int filter_info = H5.H5Zget_filter_info(HDF5Constants.H5Z_FILTER_SHUFFLE);
if (((filter_info & HDF5Constants.H5Z_FILTER_CONFIG_ENCODE_ENABLED) == 0)
|| ((filter_info & HDF5Constants.H5Z_FILTER_CONFIG_DECODE_ENABLED) == 0)) {
System.out
.println("Shuffle filter not available for encoding and decoding.");
return false;
}
}
catch (Exception e) {
e.printStackTrace();
}
return true;
}
private static void writeShuffle() {
int file_id = -1;
int filespace_id = -1;
int dataset_id = -1;
int dcpl_id = -1;
long[] dims = { DIM_X, DIM_Y };
long[] chunk_dims = { CHUNK_X, CHUNK_Y };
int[][] dset_data = new int[DIM_X][DIM_Y];
// 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_id = H5.H5Fcreate(FILENAME, HDF5Constants.H5F_ACC_TRUNC,
HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
}
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);
}
catch (Exception e) {
e.printStackTrace();
}
// Create the dataset creation property list, add the shuffle
// filter and the gzip compression filter.
// The order in which the filters are added here is significant -
// we will see much greater results when the shuffle is applied
// first. The order in which the filters are added to the property
// list is the order in which they will be invoked when writing
// data.
try {
dcpl_id = H5.H5Pcreate(HDF5Constants.H5P_DATASET_CREATE);
if (dcpl_id >= 0) {
H5.H5Pset_shuffle(dcpl_id);
H5.H5Pset_deflate(dcpl_id, 9);
// Set the chunk size.
H5.H5Pset_chunk(dcpl_id, NDIMS, chunk_dims);
}
}
catch (Exception e) {
e.printStackTrace();
}
// Create the dataset.
try {
if ((file_id >= 0) && (filespace_id >= 0) && (dcpl_id >= 0))
dataset_id = H5.H5Dcreate(file_id, DATASETNAME,
HDF5Constants.H5T_STD_I32LE, filespace_id, dcpl_id);
}
catch (Exception e) {
e.printStackTrace();
}
// Write the data to the dataset.
try {
if (dataset_id >= 0)
H5.H5Dwrite(dataset_id, HDF5Constants.H5T_NATIVE_INT,
HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
HDF5Constants.H5P_DEFAULT, 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 (dataset_id >= 0)
H5.H5Dclose(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 {
if (file_id >= 0)
H5.H5Fclose(file_id);
}
catch (Exception e) {
e.printStackTrace();
}
}
private static void readShuffle() {
int file_id = -1;
int dataset_id = -1;
int dcpl_id = -1;
int[][] dset_data = new int[DIM_X][DIM_Y];
// Open an existing file.
try {
file_id = H5.H5Fopen(FILENAME, HDF5Constants.H5F_ACC_RDONLY,
HDF5Constants.H5P_DEFAULT);
}
catch (Exception e) {
e.printStackTrace();
}
// Open an existing dataset.
try {
if (file_id >= 0)
dataset_id = H5.H5Dopen(file_id, DATASETNAME);
}
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();
}
// Retrieve the number of filters, and retrieve and print the
// type of each.
try {
if (dcpl_id >= 0) {
int nfilters = H5.H5Pget_nfilters(dcpl_id);
for (int indx = 0; indx < nfilters; indx++) {
// Java lib requires a valid filter_name object and cd_values
int[] flags = { 0 };
int[] cd_nelmts = { 1 };
int[] cd_values = { 0 };
String[] filter_name = { "" };
int filter_type = -1;
filter_type = H5.H5Pget_filter(dcpl_id, indx, flags, cd_nelmts,
cd_values, 120, filter_name);
System.out.print("Filter " + indx + ": Type is: ");
switch (H5Z_filter.get(filter_type)) {
case H5Z_FILTER_DEFLATE:
System.out.println("H5Z_FILTER_DEFLATE");
break;
case H5Z_FILTER_SHUFFLE:
System.out.println("H5Z_FILTER_SHUFFLE");
break;
case H5Z_FILTER_FLETCHER32:
System.out.println("H5Z_FILTER_FLETCHER32");
break;
case H5Z_FILTER_SZIP:
System.out.println("H5Z_FILTER_SZIP");
break;
default:
System.out.println("H5Z_FILTER_ERROR");
}
System.out.println();
}
}
}
catch (Exception e) {
e.printStackTrace();
}
// Read the data using the default properties.
try {
if (dataset_id >= 0) {
H5.H5Dread(dataset_id, HDF5Constants.H5T_NATIVE_INT,
HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
HDF5Constants.H5P_DEFAULT, dset_data);
}
}
catch (Exception e) {
e.printStackTrace();
}
// Find the maximum value in the dataset, to verify that it was read
// correctly.
int max = dset_data[0][0];
for (int indx = 0; indx < DIM_X; indx++) {
for (int jndx = 0; jndx < DIM_Y; jndx++)
if (max < dset_data[indx][jndx])
max = dset_data[indx][jndx];
}
// Print the maximum value.
System.out.println("Maximum value in " + DATASETNAME + " is: " + max);
// 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)
H5.H5Dclose(dataset_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) {
// Check if gzip compression is available and can be used for both
// compression and decompression. Normally we do not perform error
// checking in these examples for the sake of clarity, but in this
// case we will make an exception because this filter is an
// optional part of the hdf5 library.
// Similarly, check for availability of the shuffle filter.
if (H5Ex_D_Shuffle.checkGzipFilter() && H5Ex_D_Shuffle.checkShuffleFilter()) {
H5Ex_D_Shuffle.writeShuffle();
H5Ex_D_Shuffle.readShuffle();
}
}
}