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+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * 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. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * This example illustrates how to create a compressed dataset.
+ * It is used in the HDF5 Tutorial.
+ */
+
+#include <iostream>
+#include <string>
+
+#include "H5Cpp.h"
+
+#ifndef H5_NO_NAMESPACE
+ using namespace H5;
+#ifndef H5_NO_STD
+ using std::cout;
+ using std::endl;
+#endif // H5_NO_STD
+#endif
+
+const H5std_string FILE_NAME("cmprss.h5");
+const H5std_string DATASET_NAME("Compressed_Data");
+const int DIM0 = 100;
+const int DIM1 = 20;
+
+int main (void)
+{
+ hsize_t dims[2] = { DIM0, DIM1 }; // dataset dimensions
+ hsize_t chunk_dims[2] = { 20, 20 }; // chunk dimensions
+ int i,j, buf[DIM0][DIM1];
+
+ // Try block to detect exceptions raised by any of the calls inside it
+ try
+ {
+ // Turn off the auto-printing when failure occurs so that we can
+ // handle the errors appropriately
+ Exception::dontPrint();
+
+ // Create a new file using the default property lists.
+ H5File file(FILE_NAME, H5F_ACC_TRUNC);
+
+ // Create the data space for the dataset.
+ DataSpace *dataspace = new DataSpace(2, dims);
+
+ // Modify dataset creation property to enable chunking
+ DSetCreatPropList *plist = new DSetCreatPropList;
+ plist->setChunk(2, chunk_dims);
+
+ // Set ZLIB (DEFLATE) Compression using level 6.
+ // To use SZIP compression comment out this line.
+ plist->setDeflate(6);
+
+ // Uncomment these lines to set SZIP Compression
+ // unsigned szip_options_mask = H5_SZIP_NN_OPTION_MASK;
+ // unsigned szip_pixels_per_block = 16;
+ // plist->setSzip(szip_options_mask, szip_pixels_per_block);
+
+ // Create the dataset.
+ DataSet *dataset = new DataSet(file.createDataSet( DATASET_NAME,
+ PredType::STD_I32BE, *dataspace, *plist) );
+
+ for (i = 0; i< DIM0; i++)
+ for (j=0; j<DIM1; j++)
+ buf[i][j] = i+j;
+
+ // Write data to dataset.
+ dataset->write(buf, PredType::NATIVE_INT);
+
+ // Close objects and file. Either approach will close the HDF5 item.
+ delete dataspace;
+ delete dataset;
+ delete plist;
+ file.close();
+
+ // -----------------------------------------------
+ // Re-open the file and dataset, retrieve filter
+ // information for dataset and read the data back.
+ // -----------------------------------------------
+
+ int rbuf[DIM0][DIM1];
+ int numfilt;
+ size_t nelmts={1}, namelen={1};
+ unsigned flags, filter_info, cd_values[1], idx;
+ char name[1];
+ H5Z_filter_t filter_type;
+
+ // Open the file and the dataset in the file.
+ file.openFile(FILE_NAME, H5F_ACC_RDONLY);
+ dataset = new DataSet(file.openDataSet( DATASET_NAME));
+
+ // Get the create property list of the dataset.
+ plist = new DSetCreatPropList(dataset->getCreatePlist ());
+
+ // Get the number of filters associated with the dataset.
+ numfilt = plist->getNfilters();
+ cout << "Number of filters associated with dataset: " << numfilt << endl;
+
+ for (idx=0; idx < numfilt; idx++) {
+ nelmts = 0;
+
+ filter_type = plist->getFilter(idx, flags, nelmts, cd_values, namelen, name , filter_info);
+
+ cout << "Filter Type: ";
+
+ switch (filter_type) {
+ case H5Z_FILTER_DEFLATE:
+ cout << "H5Z_FILTER_DEFLATE" << endl;
+ break;
+ case H5Z_FILTER_SZIP:
+ cout << "H5Z_FILTER_SZIP" << endl;
+ break;
+ default:
+ cout << "Other filter type included." << endl;
+ }
+ }
+
+ // Read data.
+ dataset->read(rbuf, PredType::NATIVE_INT);
+
+ delete plist;
+ delete dataset;
+ file.close(); // can be skipped
+
+ } // end of try block
+
+ // catch failure caused by the H5File operations
+ catch(FileIException error)
+ {
+ error.printError();
+ return -1;
+ }
+
+ // catch failure caused by the DataSet operations
+ catch(DataSetIException error)
+ {
+ error.printError();
+ return -1;
+ }
+
+ // catch failure caused by the DataSpace operations
+ catch(DataSpaceIException error)
+ {
+ error.printError();
+ return -1;
+ }
+
+ return 0; // successfully terminated
+}
+