path: root/c++/test/dsets.cpp

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * 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     *
 * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
 * access to either file, you may request a copy from help@hdfgroup.org.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*****************************************************************************
   FILE
   dsets.cpp - HDF5 C++ testing the functionalities associated with the
	       C dataset interface (H5D)

   EXTERNAL ROUTINES/VARIABLES:
     These routines are in the test directory of the C library:
	h5_reset() -- in h5test.c, resets the library by closing it
	h5_fileaccess() -- in h5test.c, returns a file access template

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

#ifdef OLD_HEADER_FILENAME
#include <iostream.h>
#else
#include <iostream>
#endif
#include <string>

#ifndef H5_NO_NAMESPACE
#ifndef H5_NO_STD
    using std::cerr;
    using std::endl;
#endif  // H5_NO_STD
#endif

#include "H5Cpp.h"	// C++ API header file

#ifndef H5_NO_NAMESPACE
    using namespace H5;
#endif

#include "h5cpputil.h"	// C++ utilility header file

const H5std_string	FILE1("dataset.h5");
const H5std_string	DSET_DEFAULT_NAME("default");
const H5std_string	DSET_CHUNKED_NAME("chunked");
const H5std_string	DSET_SIMPLE_IO_NAME("simple_io");
const H5std_string	DSET_TCONV_NAME	("tconv");
const H5std_string	DSET_COMPRESS_NAME("compressed");
const H5std_string	DSET_BOGUS_NAME	("bogus");

const int H5Z_FILTER_BOGUS = 305;

// Local prototypes
static size_t filter_bogus(unsigned int flags, size_t cd_nelmts,
    const unsigned int *cd_values, size_t nbytes, size_t *buf_size, void **buf);

/*-------------------------------------------------------------------------
 * Function:	test_create
 *
 * Purpose:	Attempts to create a dataset.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Friday, January 5, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_create( H5File& file)
{
    SUBTEST("create, open, close");

    // Setting this to NULL for cleaning up in failure situations
    DataSet *dataset = NULL;
    try {
	// Create a data space
	hsize_t     dims[2];
	dims[0] = 256;
	dims[1] = 512;
	DataSpace space (2, dims, NULL);

	// Create a dataset using the default dataset creation properties.
	// We're not sure what they are, so we won't check.
	dataset = new DataSet (file.createDataSet
		(DSET_DEFAULT_NAME, PredType::NATIVE_DOUBLE, space));

	// Add a comment to the dataset
	file.setComment (DSET_DEFAULT_NAME, "This is a dataset");

	// Close the dataset
	delete dataset;
	dataset = NULL;

	// Try creating a dataset that already exists.  This should fail since a
	// dataset can only be created once.  If an exception is not thrown for
	// this action by createDataSet, then throw an invalid action exception.
	try {
	    dataset = new DataSet (file.createDataSet
			(DSET_DEFAULT_NAME, PredType::NATIVE_DOUBLE, space));

	    // continuation here, that means no exception has been thrown
	    throw InvalidActionException("H5File::createDataSet", "Library allowed overwrite of existing dataset");
	}
	catch (FileIException E)	// catching invalid creating dataset
	{} // do nothing, exception expected

	// Open the dataset we created above and then close it.  This is one
	// way to open an existing dataset for accessing.
	dataset = new DataSet (file.openDataSet (DSET_DEFAULT_NAME));

	// Get and verify the comment from this dataset, using
	// H5std_string getComment(const H5std_string& name, <buf_size=0, by default>)
	H5std_string comment = file.getComment(DSET_DEFAULT_NAME);
	verify_val(comment, "This is a dataset", "H5Location::getComment", __LINE__, __FILE__);

	// Close the dataset when accessing is completed
	delete dataset;

	// This is another way to open an existing dataset for accessing.
	DataSet another_dataset(file.openDataSet (DSET_DEFAULT_NAME));

	// Try opening a non-existent dataset.  This should fail so if an
	// exception is not thrown for this action by openDataSet, then
	// display failure information and throw an exception.
	try {
	    dataset = new DataSet (file.openDataSet( "does_not_exist" ));

	    // continuation here, that means no exception has been thrown
	    throw InvalidActionException("H5File::openDataSet", "Attempted to open a non-existent dataset");
	}
	catch (FileIException E ) // catching creating non-existent dataset
	{} // do nothing, exception expected

	// Create a new dataset that uses chunked storage instead of the default
	// layout.
	DSetCreatPropList create_parms;
	hsize_t     csize[2];
	csize[0] = 5;
	csize[1] = 100;
	create_parms.setChunk( 2, csize );

	dataset = new DataSet (file.createDataSet
		(DSET_CHUNKED_NAME, PredType::NATIVE_DOUBLE, space, create_parms));
	// Note: this one has no error message in C when failure occurs?

	// clean up and return with success
	delete dataset;

	PASSED();
	return 0;
    }	// outer most try block

    catch (InvalidActionException E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	// clean up and return with failure
	if (dataset != NULL)
	    delete dataset;
	return -1;
    }
    // catch all other exceptions
    catch (Exception E)
    {
	issue_fail_msg("test_create", __LINE__, __FILE__);

	// clean up and return with failure
	if (dataset != NULL)
	    delete dataset;
	return -1;
    }
}   // test_create

/*-------------------------------------------------------------------------
 * Function:	test_simple_io
 *
 * Purpose:	Tests simple I/O.  That is, reading and writing a complete
 *		multi-dimensional array without data type or data space
 *		conversions, without compression, and stored contiguously.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Friday, January 5, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_simple_io( H5File& file)
{

    SUBTEST("simple I/O");

    int	points[100][200];
    int	check[100][200];
    int		i, j, n;

    // Initialize the dataset
    for (i = n = 0; i < 100; i++)
    {
	for (j = 0; j < 200; j++) {
	    points[i][j] = n++;
	}
    }

    char* tconv_buf = new char [1000];
    try
    {
	// Create the data space
	hsize_t	dims[2];
	dims[0] = 100;
	dims[1] = 200;
	DataSpace space (2, dims, NULL);

	// Create a small conversion buffer to test strip mining
	DSetMemXferPropList xfer;

	xfer.setBuffer (1000, tconv_buf, NULL);

	// Create the dataset
	DataSet dataset (file.createDataSet (DSET_SIMPLE_IO_NAME, PredType::NATIVE_INT, space));

	// Write the data to the dataset
	dataset.write ((void*) points, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Read the dataset back
	dataset.read ((void*) check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Check that the values read are the same as the values written
	for (i = 0; i < 100; i++)
	    for (j = 0; j < 200; j++)
	    {
		int status = check_values (i, j, points[i][j], check[i][j]);
		if (status == -1)
		    throw Exception("DataSet::read");
	    }

	// clean up and return with success
	delete [] tconv_buf;
	PASSED();
	return 0;
    }  // end try

    // catch all dataset, space, plist exceptions
    catch (Exception E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	// clean up and return with failure
	if (tconv_buf)
	    delete [] tconv_buf;
	return -1;
    }
}   // test_simple_io

/*-------------------------------------------------------------------------
 * Function:	test_datasize
 *
 * Purpose:	Tests DataSet::getInMemDataSize().  
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler
 *		Thursday, March 22, 2012
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_datasize(FileAccPropList &fapl)
{
    SUBTEST("DataSet::getInMemDataSize()");
    try
    {
	// Open FILE1.
	H5File file(FILE1, H5F_ACC_RDWR, FileCreatPropList::DEFAULT, fapl);

	// Open dataset DSET_SIMPLE_IO_NAME.
	DataSet dset = file.openDataSet (DSET_SIMPLE_IO_NAME);

	// Get the dataset's dataspace to calculate the size for verification.
	DataSpace space(dset.getSpace());

	// Get the dimension sizes.
	hsize_t dims[2];
	int n_dims = space.getSimpleExtentDims(dims);

	// Calculate the supposed size.  Size of each value is int (4), from
	// test_simple_io.
	int expected_size = 4 * dims[0] * dims[1];

	// getInMemDataSize() returns the in memory size of the data.
	size_t ds_size = dset.getInMemDataSize();

	// Verify the data size.
	if (ds_size != expected_size)
	{
	    H5_FAILED();
	    cerr << " Expected data size = " << expected_size;
	    cerr << " but dset.getInMemDataSize() returned " << ds_size << endl;
	    throw Exception("test_compression", "Failed in testing DataSet::getInMemDataSize()");
	}

	PASSED();
	return 0;
    }  // end try

    // catch all dataset, space, plist exceptions
    catch (Exception E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	return -1;
    }
}   // test_datasize

/*-------------------------------------------------------------------------
 * Function:	test_tconv
 *
 * Purpose:	Test some simple data type conversion stuff.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Friday, January 5, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_tconv( H5File& file)
{
    // Prepare buffers for input/output
    char	*out=NULL, *in=NULL;
    out = new char [4*1000000];
    // assert (out); - should use exception handler for new - BMR
    in = new char [4*1000000];
    //assert (in);

    SUBTEST("data type conversion");

    // Initialize the dataset
    for (int i = 0; i < 1000000; i++) {
	out[i*4+0] = 0x11;
	out[i*4+1] = 0x22;
	out[i*4+2] = 0x33;
	out[i*4+3] = 0x44;
    }

    try
    {
	// Create the data space
	hsize_t	dims[1];
	dims[0] = 1000000;
	DataSpace space (1, dims, NULL);

	// Create the data set
	DataSet dataset (file.createDataSet (DSET_TCONV_NAME, PredType::STD_I32LE, space));

	// Write the data to the dataset
	dataset.write ((void*) out, PredType::STD_I32LE);

	// Read data with byte order conversion
	dataset.read ((void*) in, PredType::STD_I32BE);

	// Check
	for (int i = 0; i < 1000000; i++) {
	    if (in[4*i+0]!=out[4*i+3] ||
		in[4*i+1]!=out[4*i+2] ||
		in[4*i+2]!=out[4*i+1] ||
		in[4*i+3]!=out[4*i+0])
	    {
		throw Exception("DataSet::read", "Read with byte order conversion failed");
	    }
	}

	// clean up and return with success
	delete [] out;
	delete [] in;
	PASSED();
	return 0;
    }  // end try

    // catch all dataset and space exceptions
    catch (Exception E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	// clean up and return with failure
	delete [] out;
	delete [] in;
	return -1;
    }
}   // test_tconv

/* This message derives from H5Z */
const H5Z_class2_t H5Z_BOGUS[1] = {{
    H5Z_CLASS_T_VERS,		/* H5Z_class_t version number   */
    H5Z_FILTER_BOGUS,		/* Filter id number		*/
    1, 1,			/* Encode and decode enabled    */
    "bogus",			/* Filter name for debugging	*/
    NULL,                       /* The "can apply" callback     */
    NULL,                       /* The "set local" callback     */
    (H5Z_func_t)filter_bogus,   /* The actual filter function	*/
}};

/*-------------------------------------------------------------------------
 * Function:	bogus
 *
 * Purpose:	A bogus compression method that doesn't do anything.
 *
 * Return:	Success:	Data chunk size
 *
 *		Failure:	0
 *
 * Programmer:	Robb Matzke
 *		Tuesday, April 21, 1998
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static size_t
/*bogus(unsigned int UNUSED flags, size_t UNUSED cd_nelmts,
      const unsigned int UNUSED cd_values[], size_t nbytes,
      size_t UNUSED *buf_size, void UNUSED **buf)
BMR: removed UNUSED for now until asking Q. or R. to pass compilation*/
filter_bogus(unsigned int flags, size_t cd_nelmts,
      const unsigned int cd_values[], size_t nbytes,
      size_t *buf_size, void **buf)
{
    return nbytes;
}

/*-------------------------------------------------------------------------
 * Function:	test_compression
 *
 * Purpose:	Tests dataset compression. If compression is requested when
 *		it hasn't been compiled into the library (such as when
 *		updating an existing compressed dataset) then data is sent to
 *		the file uncompressed but no errors are returned.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Friday, January 5, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_compression(H5File& file)
{
#ifndef H5_HAVE_FILTER_DEFLATE
    const char		*not_supported;
    not_supported = "    Deflate compression is not enabled.";
#endif /* H5_HAVE_FILTER_DEFLATE */
    int		points[100][200];
    int		check[100][200];
    hsize_t	i, j, n;

    // Initialize the dataset
    for (i = n = 0; i < 100; i++)
    {
	for (j = 0; j < 200; j++) {
	    points[i][j] = (int)n++;
	}
    }
    char* tconv_buf = new char [1000];
    DataSet* dataset = NULL;
    try
    {
	const hsize_t	size[2] = {100, 200};
	// Create the data space
	DataSpace space1(2, size, NULL);

	// Create a small conversion buffer to test strip mining
	DSetMemXferPropList xfer;

	xfer.setBuffer (1000, tconv_buf, NULL);

	// Use chunked storage with compression
	DSetCreatPropList dscreatplist;

	const hsize_t	chunk_size[2] = {2, 25};
	dscreatplist.setChunk (2, chunk_size);
	dscreatplist.setDeflate (6);

#ifdef H5_HAVE_FILTER_DEFLATE
	SUBTEST("Compression (setup)");

	// Create the dataset
	dataset = new DataSet (file.createDataSet
	    (DSET_COMPRESS_NAME, PredType::NATIVE_INT, space1, dscreatplist));

	PASSED();

	/*----------------------------------------------------------------------
	* STEP 1: Read uninitialized data.  It should be zero.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (uninitialized read)");

	dataset->read ((void*) check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	for (i=0; i<size[0]; i++) {
	    for (j=0; j<size[1]; j++) {
		if (0!=check[i][j]) {
		    H5_FAILED();
		    cerr << "    Read a non-zero value." << endl;
		    cerr << "    At index " << (unsigned long)i << "," <<
		   (unsigned long)j << endl;
		    throw Exception("test_compression", "Failed in uninitialized read");
		}
	    }
	}
	PASSED();

	/*----------------------------------------------------------------------
	* STEP 2: Test compression by setting up a chunked dataset and writing
	* to it.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (write)");

	for (i=n=0; i<size[0]; i++)
	{
	    for (j=0; j<size[1]; j++)
	    {
		points[i][j] = (int)n++;
	    }
	}

	dataset->write ((void*) points, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	PASSED();

	/*----------------------------------------------------------------------
	* STEP 3: Try to read the data we just wrote.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (read)");

	// Read the dataset back
	dataset->read ((void*)check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Check that the values read are the same as the values written
	for (i = 0; i < size[0]; i++)
	    for (j = 0; j < size[1]; j++)
	    {
		int status = check_values (i, j, points[i][j], check[i][j]);
		if (status == -1)
		    throw Exception("test_compression", "Failed in read");
	    }

	PASSED();

	/*----------------------------------------------------------------------
	* STEP 4: Write new data over the top of the old data.  The new data is
	* random thus not very compressible, and will cause the chunks to move
	* around as they grow.  We only change values for the left half of the
	* dataset although we rewrite the whole thing.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (modify)");

	for (i=0; i<size[0]; i++)
	{
	    for (j=0; j<size[1]/2; j++)
	    {
	    	points[i][j] = rand ();
	    }
	}
	dataset->write ((void*)points, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Read the dataset back and check it
	dataset->read ((void*)check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Check that the values read are the same as the values written
	for (i = 0; i < size[0]; i++)
	    for (j = 0; j < size[1]; j++)
	    {
		int status = check_values (i, j, points[i][j], check[i][j]);
		if (status == -1)
		    throw Exception("test_compression", "Failed in modify");
	    }

	PASSED();

	/*----------------------------------------------------------------------
	* STEP 5: Close the dataset and then open it and read it again.  This
	* insures that the compression message is picked up properly from the
	* object header.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (re-open)");

	// close this dataset to reuse the var
	delete dataset;

	dataset = new DataSet (file.openDataSet (DSET_COMPRESS_NAME));
	dataset->read ((void*)check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Check that the values read are the same as the values written
	for (i = 0; i < size[0]; i++)
	    for (j = 0; j < size[1]; j++)
	    {
		int status = check_values (i, j, points[i][j], check[i][j]);
		if (status == -1)
		    throw Exception("test_compression", "Failed in re-open");
	    }

	PASSED();


	/*----------------------------------------------------------------------
	* STEP 6: Test partial I/O by writing to and then reading from a
	* hyperslab of the dataset.  The hyperslab does not line up on chunk
	* boundaries (we know that case already works from above tests).
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (partial I/O)");

	const hsize_t	hs_size[2] = {4, 50};
	const hsize_t	hs_offset[2] = {7, 30};
	for (i = 0; i < hs_size[0]; i++) {
	    for (j = 0; j < hs_size[1]; j++) {
		points[hs_offset[0]+i][hs_offset[1]+j] = rand ();
	    }
	}
	space1.selectHyperslab( H5S_SELECT_SET, hs_size, hs_offset );
	dataset->write ((void*)points, PredType::NATIVE_INT, space1, space1, xfer);
	dataset->read ((void*)check, PredType::NATIVE_INT, space1, space1, xfer);

	// Check that the values read are the same as the values written
	for (i=0; i<hs_size[0]; i++) {
	for (j=0; j<hs_size[1]; j++) {
	    if (points[hs_offset[0]+i][hs_offset[1]+j] !=
		check[hs_offset[0]+i][hs_offset[1]+j]) {
		H5_FAILED();
		cerr << "    Read different values than written.\n" << endl;
		cerr << "    At index " << (unsigned long)(hs_offset[0]+i) <<
		   "," << (unsigned long)(hs_offset[1]+j) << endl;

		cerr << "    At original: " << (int)points[hs_offset[0]+i][hs_offset[1]+j] << endl;
		cerr << "    At returned: " << (int)check[hs_offset[0]+i][hs_offset[1]+j] << endl;
		throw Exception("test_compression", "Failed in partial I/O");
	    }
	} // for j
	} // for i

	delete dataset;
	dataset = NULL;

	PASSED();

#else
	SUBTEST("deflate filter");
	SKIPPED();
	cerr << not_supported << endl;
#endif

	/*----------------------------------------------------------------------
	* STEP 7: Register an application-defined compression method and use it
	* to write and then read the dataset.
	*----------------------------------------------------------------------
	*/
	SUBTEST("Compression (app-defined method)");

        if (H5Zregister (H5Z_BOGUS)<0)
		throw Exception("test_compression", "Failed in app-defined method");
	if (H5Pset_filter (dscreatplist.getId(), H5Z_FILTER_BOGUS, 0, 0, NULL)<0)
	    throw Exception("test_compression", "Failed in app-defined method");
	dscreatplist.setFilter (H5Z_FILTER_BOGUS, 0, 0, NULL);

	DataSpace space2 (2, size, NULL);
	dataset = new DataSet (file.createDataSet (DSET_BOGUS_NAME, PredType::NATIVE_INT, space2, dscreatplist));

	dataset->write ((void*)points, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);
	dataset->read ((void*)check, PredType::NATIVE_INT, DataSpace::ALL, DataSpace::ALL, xfer);

	// Check that the values read are the same as the values written
	for (i = 0; i < size[0]; i++)
	    for (j = 0; j < size[1]; j++)
	    {
		int status = check_values (i, j, points[i][j], check[i][j]);
		if (status == -1)
		    throw Exception("test_compression", "Failed in app-defined method");
	    }

	PASSED();

	/*----------------------------------------------------------------------
	* Cleanup
	*----------------------------------------------------------------------
	*/
	delete dataset;
	delete [] tconv_buf;
	return 0;
    } // end try

    // catch all dataset, file, space, and plist exceptions
    catch (Exception E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	// clean up and return with failure
	if (dataset != NULL)
	    delete dataset;
	if (tconv_buf)
	    delete [] tconv_buf;
	return -1;
    }
}   // test_compression

/*-------------------------------------------------------------------------
 * Function:	test_multiopen
 *
 * Purpose:	Tests that a bug no longer exists.  If a dataset is opened
 *		twice and one of the handles is used to extend the dataset,
 *		then the other handle should return the new size when
 *		queried.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Saturday, February 17, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_multiopen (H5File& file)
{

    SUBTEST("Multi-open with extending");

    DataSpace* space = NULL;
    try {

	// Create a dataset creation property list
	DSetCreatPropList dcpl;

	// Set chunk size to given size
	hsize_t		cur_size[1] = {10};
	dcpl.setChunk (1, cur_size);

	// Create a simple data space with unlimited size
	static hsize_t	max_size[1] = {H5S_UNLIMITED};
	space = new DataSpace (1, cur_size, max_size);

	// Create first dataset
	DataSet dset1 = file.createDataSet ("multiopen", PredType::NATIVE_INT, *space, dcpl);

	// Open again the first dataset from the file to another DataSet object.
	DataSet dset2 = file.openDataSet ("multiopen");

	// Relieve the dataspace
	delete space;
	space = NULL;

	// Extend the dimensionality of the first dataset
	cur_size[0] = 20;
	dset1.extend (cur_size);

	// Get the size from the second handle
	space = new DataSpace (dset2.getSpace());

	hsize_t		tmp_size[1];
	space->getSimpleExtentDims (tmp_size);
	if (cur_size[0]!=tmp_size[0])
	{
	    cerr << "    Got " << (int)tmp_size[0] << " instead of "
		    << (int)cur_size[0] << "!" << endl;
	    throw Exception("test_multiopen", "Failed in multi-open with extending");
	}

	// clean up and return with success
	delete space;
	PASSED();
	return 0;
    } // end try block

    // catch all dataset, file, space, and plist exceptions
    catch (Exception E)
    {
	cerr << " FAILED" << endl;
	cerr << "    <<<  " << E.getDetailMsg() << "  >>>" << endl << endl;

	// clean up and return with failure
	if (space != NULL)
	    delete space;
	return -1;
    }
}   // test_multiopen

/*-------------------------------------------------------------------------
 * Function:	test_types
 *
 * Purpose:	Test various types - should be moved to dtypes.cpp
 *
 * Return:	Success:	0
 *
 *		Failure:	-1
 *
 * Programmer:  Binh-Minh Ribler (using C version)
 *		February 17, 2001
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
test_types(H5File& file)
{
    SUBTEST("Various datatypes");

    size_t		i;
    DataSet* dset = NULL;
    try {

	// Create a group in the file that was passed in from the caller
	Group grp = file.createGroup ("typetests");

	/* bitfield_1 */
	unsigned char	buf[32];
	hsize_t nelmts = sizeof(buf);
	DataType type;
	try { // block of bitfield_1
	    // test copying a predefined type
	    type.copy (PredType::STD_B8LE);

	    // Test copying a user-defined type using DataType::copy
	    DataType copied_type;
	    copied_type.copy(type);

	    // Test copying a user-defined type using DataType::operator=
	    DataType another_copied_type;
	    another_copied_type = type;

	    // Test copying a user-defined int type using DataType::operator=
	    IntType orig_int(PredType::STD_B8LE);
	    DataType generic_type;
	    generic_type = orig_int;

	    // Test copying an integer predefined type
	    IntType new_int_type(PredType::STD_B8LE);

	    // Test copying an int predefined type using DataType::operator=
	    IntType another_int_type;
	    another_int_type = new_int_type;

	    DataSpace space (1, &nelmts);
	    dset = new DataSet(grp.createDataSet("bitfield_1", type, space));

	    // Fill buffer
	    for (i=0; i<sizeof buf; i++)
	    	buf[i] = (unsigned char)0xff ^ (unsigned char)i;

	    // Write data from buf using all default dataspaces and property list
	    dset->write (buf, type);

	    // no failure in bitfield_1, close this dataset
	    delete dset;
	} // end try block of bitfield_1

	// catch exceptions thrown in try block of bitfield_1
	catch (Exception E)
	{
	    cerr << " FAILED" << endl;
	    cerr << "    <<<  " << "bitfield_1: " << E.getFuncName()
		 << " - " << E.getDetailMsg() << "  >>>" << endl << endl;
	    if (dset != NULL)
		delete dset;
	    return -1;
	}

	/* bitfield_2 */
	nelmts = sizeof(buf)/2;
	try { // bitfield_2 block
	    type.copy (PredType::STD_B16LE);
	    DataSpace space (1, &nelmts);
	    dset = new DataSet(grp.createDataSet("bitfield_2", type, space));

	    // Fill buffer
	    for (i=0; i<sizeof(buf); i++)
		buf[i] = (unsigned char)0xff ^ (unsigned char)i;

	    // Write data from buf using all default dataspaces and property
	    // list; if writing fails, deallocate dset and return.
	    dset->write (buf, type);

	    // no failure in bitfield_2, close this dataset and reset for
	    // variable reuse
	    delete dset;
	    dset = NULL;
	} // end try block of bitfield_2

	// catch exceptions thrown in try block of bitfield_2
	catch (Exception E) {
	    cerr << " FAILED" << endl;
	    cerr << "    <<<  " << "bitfield_2: " << E.getFuncName()
		 << " - " << E.getDetailMsg() << "  >>>" << endl << endl;
	    if (dset != NULL)
		delete dset;
	    throw E; // propagate the exception
	}

	/* opaque_1 */
	DataType* optype = NULL;
	try { // opaque_1 block
	    optype = new DataType(H5T_OPAQUE, 1);
	    nelmts = sizeof(buf);
	    DataSpace space (1, &nelmts);
	    optype->setTag ("testing 1-byte opaque type");
	    dset = new DataSet(grp.createDataSet("opaque_1", *optype, space));

	    // Fill buffer
	    for (i=0; i<sizeof buf; i++)
		buf[i] = (unsigned char)0xff ^ (unsigned char)i;

	    // Write data from buf using all default dataspaces and property
	    // list; if writing fails, deallocate dset and return.
	    dset->write (buf, *optype);

	    // no failure in opaque_1
	    delete dset; dset = NULL;
	    delete optype; optype = NULL;
	} // end try block of opaque_1

	// catch exceptions thrown in try block of opaque_1
	catch (Exception E) {
	    cerr << " FAILED" << endl;
	    cerr << "    <<<  " << "opaque_1: " << E.getFuncName()
		 << " - " << E.getDetailMsg() << "  >>>" << endl << endl;
	    if (dset != NULL)
		delete dset;
	    if (optype != NULL)
		delete optype;
	    throw E; // propagate the exception
	}

	/* opaque_2 */
	try { // block opaque_2
	    nelmts = sizeof(buf)/4;
	    DataSpace space (1, &nelmts);
	    optype = new DataType(H5T_OPAQUE, 4);
	    optype->setTag ("testing 4-byte opaque type");
	    dset = new DataSet(grp.createDataSet("opaque_2", *optype, space));

	    // Fill buffer
	    for (i=0; i<sizeof(buf); i++)
		buf[i] = (unsigned char)0xff ^ (unsigned char)i;

	    // Write data from buf using all default dataspaces and property
	    // list; if writing fails, deallocate dset and return.
	    dset->write (buf, *optype);

	    // no failure in opaque_1
	    delete dset; dset = NULL;
	    delete optype; optype = NULL;
	} //end try block of opaque_2

	// catch exceptions thrown in try block of opaque_2
	catch (Exception E) {
	    cerr << " FAILED" << endl;
	    cerr << "    <<<  " << "opaque_2: " << E.getFuncName()
		 << " - " << E.getDetailMsg() << "  >>>" << endl << endl;
	    if (dset != NULL)
		delete dset;
	    if (optype != NULL)
		delete optype;
	    throw E; // propagate the exception
	}

	PASSED();
	return 0;
    } // end top try block

    catch (Exception E)
    {
	return -1;
    }
}   // test_types

/*-------------------------------------------------------------------------
 * Function:	test_dset
 *
 * Purpose:	Tests the dataset interface (H5D)
 *
 * Return:	Success: 0
 *
 *		Failure: -1
 *
 * Programmer:	Binh-Minh Ribler (using C version)
 *		Friday, January 5, 2001
 *
 * Modifications:
 *	Nov 12, 01:
 *		- moved h5_cleanup to outside of try block because
 *		  dataset.h5 cannot be removed until "file" is out of
 *		  scope and dataset.h5 is closed.
 *	Feb 20, 05:
 *		- cleanup_dsets took care of the cleanup now.
 *
 *-------------------------------------------------------------------------
 */
#ifdef __cplusplus
extern "C"
#endif
void test_dset()
{
    hid_t	fapl_id;
    fapl_id = h5_fileaccess(); // in h5test.c, returns a file access template

    int		nerrors=0;	// keep track of number of failures occurr

    try
    {
	// Turn of the auto-printing when failure occurs so that we can
	// handle the errors appropriately since sometime failures are
	// caused deliberately and expected.
	Exception::dontPrint();

	// Use the file access template id to create a file access prop.
	// list object to pass in H5File::H5File
	FileAccPropList fapl(fapl_id);

	H5File file(FILE1, H5F_ACC_TRUNC, FileCreatPropList::DEFAULT, fapl);

	// Cause the library to emit initial messages
	Group grp = file.createGroup( "emit diagnostics", 0);
	grp.setComment("Causes diagnostic messages to be emitted");

	nerrors += test_create(file)<0 	?1:0;
	nerrors += test_simple_io(file)<0	?1:0;
	nerrors += test_tconv(file)<0	?1:0;
	nerrors += test_compression(file)<0	?1:0;
	nerrors += test_multiopen (file)<0	?1:0;
	nerrors += test_types(file)<0       ?1:0;

	// Get part of the comment, random length using
	// ssize_t getComment(const char* name, const size_t buf_size, char* comment)
	char* comment = new char[11];
	ssize_t comment_len = file.getComment("emit diagnostics", 11, comment);
	verify_val((const char*)comment, "Causes dia", "H5Location::getComment", __LINE__, __FILE__);

	// Close group "emit diagnostics".
	grp.close();

	// Close the file before testing data size.
	file.close();
	nerrors += test_datasize(fapl) <0 ? 1:0;
    }
    catch (Exception E)
    {
	test_report(nerrors, H5std_string(" Dataset"));
    }

    // Clean up data file
    cleanup_dsets();
}   // test_dset

/*-------------------------------------------------------------------------
 * Function:    cleanup_dsets
 *
 * Purpose:     Cleanup temporary test files
 *
 * Return:      none
 *
 * Programmer:  (use C version)
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
#ifdef __cplusplus
extern "C"
#endif
void cleanup_dsets()
{
    HDremove(FILE1.c_str());
} // cleanup_dsets